Cladding Systems, Moisture Protection, Thermal Control and Air Barriers: Effective Enclosure Design Strategies
Water and Air Barriers: Methods of Protection for Wood-Frame Structures
Presented by Richard Keleher AIA, CSI, LEED AP
Disclaimer: This presentation was developed by a third party and is not funded by WoodWorks or the Softwood Lumber Board.
“The Wood Products Council” This course is registered with is a Registered Provider with AIA CES for continuing The American Institute of professional education. As Architects Continuing such, it does not include Education Systems (AIA/CES), content that may be deemed Provider #G516. or construed to be an approval or endorsement by Credit(s) earned on the AIA of any material of completion of this course will construction or any method be reported to AIA CES for AIA or manner of handling, members. Certificates of using, distributing, or dealing Completion for both AIA in any material or product. members and non-AIA ______members are available upon request. Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation. Course Description
This interactive workshop will examine the unique considerations of building enclosure design for wood-frame multi-family and commercial projects. Presented by three experts, it will break enclosure design into its main control layer topics: cladding systems, moisture protection, thermal control and air barriers. Each of these control layers will be addressed, including product options, assembly and detailing strategies, continuity, inspections, and how each control layer affects the others. Using the mid-Atlantic climate as a basis of design, the presenters will then lead a design charrette using parameters selected by the audience. Attendees can expect to gain a deeper understanding of the guiding principles of enclosure design, the variety of products, assemblies and details that can achieve desired performance, and the construction phase know-how to ensure that pen and paper details translate to real-world results. Learning Objectives
1. Review building enclosure design best practices for light wood-frame buildings.
2. Demonstrate effective methods of controlling air movement through wood-frame assemblies and discuss the resulting impacts on overall energy performance.
3. Discuss common products details used for thermal control in light wood-frame wall and roof enclosure assemblies, focusing on the differences between cavity insulation and continuous insulation.
4. Using case studies and details from successful projects, demonstrate unique considerations and best practices associated with a variety of cladding systems and flashing details at interfaces between adjacent enclosure assemblies. Details for the Building Enclosure – Air and Water Layers Details for the Building Enclosure – Water and Air Barriers
• The Thompson & Lichtner Co. Senior Architect
• Richard Keleher Architect AIA, CSI, LEED AP Independent Consultant
• Building Enclosure Services: • Design Assistance • Peer Review • Condition Surveys • Submittal Review • Construction Inspection • Fenestration and Roof Testing
• Building Enclosure Council Founding Chair
• The Green Team Concord, MA; Founder Sheehan Hall, Worcester State University, Goody Clancy Assoc.
Presented for: Mid-Atlantic Enclosure Design Workshops - WoodWorks 5 Details for the Building Enclosure – Water and Air Control Layers
This presentation is protected by US and International Copyright laws. Reproduction, distribution, display and use of the presentation without written permission of the speaker is prohibited. © Thompson & Lichtner, 2019
Disclaimer The following details are intended for educational use only and should not be incorporated directly into a design without careful consideration by a design professional.
Certain assumptions have been made about design conditions and other elements that could make the examples incorrect for some applications.
All materials are generic and no preference for one manufacturer’s product over another is implied.
6 Details for the Building Enclosure – Air and Water Layers
Learning Objectives
Attendees will learn:
1. The principles of building science and detailing of watertight enclosures, especially regarding air and water leakage. 2. Detailing of wood frame enclosures. 3. Detailing of curtain walls, storefronts, and windows. 4. Detailing of roof to wall connections.
7 Details for the Building Enclosure – Water and Air Control Layers Key Concepts
Learning Objectives 1. Five Control Layers 7. One vs. Two Vapor Retarder Application – Never Two! (except 2. Perfect Wall vs. Balanced (Hybrid) roofs that have a high relative humidity Wall vs. Conventional Wall space below) 3. Architects must clearly delineate air 8. Vapor Control, in General – see and water barriers in their Karla’s presentation for details. documents. Particularly important with vapor and 4. Rely on membranes, not metal air open insulation, such as fiberglass. flashings, to keep water out. 9. Climate (Zone 5) is where I practice. 5. 90% of construction litigation is due Key differences in Zone 5: to moisture problems. a. Code requires continuous 6. One vs. Two Air Barrier Application – insulation for Residential the more the better, but useless unless continuous. b. Code allows use of a Type I vapor retarder
8 Details for the Building Enclosure – Air and Water Layers Outline Principles • Sealants (not reliable) • Roofs • Climate • Walls at roofs • Rain Penetration Forces • Low slope roofs • Five Control Layers • Parapets • Fire Issues – not included • Expansion Joints – not included Membranes Quality Assurance Wood Frame Construction • Walls and roofs • Flanged windows Commercial Construction • Slabs on Grade – not included 15 mil. ASTMs. Sucking. Floor failures. Radon. • Opaque Walls • Cavity (veneer) walls • Precast concrete (dual seal joints) • Fenestration (connections to adjacent construction) • Curtain wall • Windows, louvers and doors • Flanged windows • Storefronts • Subsills and receptors Winsor School, William Rawn Associates 9 Details for the Building Enclosure – Water and Air Control Layers
PRINCIPLES
10 Details for the Building Enclosure – Air and Water Layers PRINCIPLES Sealants The Obvious Solution – Sealants - Not Reliable • Design Requirements • Width sufficient to accommodate movement • Width 1/2” ± 1/8” minimum
• Shape Must be Just Right (see diagram) • Correct: depth = 1/2 of width • Too thick: adhesive failure: comes of off adjacent substrate. Maximum thickness: Silicone: 3/8” Silicone doesn’t cure over 3/8” Polyurethane: ½” • Too thin: cohesive failure: comes apart
• Installation Requirements • Compatible sealant and substrate • Proper surface preparation • Proper backer rod type, position, and support • Proper tooling • Proper temperature (Cold-dampness. Hot-workability) Sealant Shapes 1 Correct shape 2 Too thick. 3 Too thin. • And, Many Causes of Deterioration • Ultraviolet radiation • Thermal cycling (worst in New England) • Standing water (horizontal joints) 11
Details for the Building Enclosure – Water and Air Control Layers PRINCIPLES Climate
US Climate Zone Map* *US Department of Energy
12 Details for the Building Enclosure – Water and Air Control Layers PRINCIPLES Control Layers The Five Control Layers
1 Rainscreen: Sheds a majority of the water and protects underlying material from damaging ultra-violet light. Always the outermost layer, usually the veneer.
2 Drainage Plane: (Sometimes labeled “water resistive barrier”). Drains the water away from (Water Barrier) substrate, incorporates flashings, drips, weeps, etc. Must be watertight!
3 Air Barrier: Prevents air leakage and consequent convective energy loss and prevents condensation due to water vapor being carried around vapor barriers, etc. An air barrier is critical to envelope performance. It prevents energy loss. It can be, and often is, used as the drainage plane. It is also often the final water barrier. No gaps! Multiple air barriers OK, but each must be complete!
4 Thermal: Prevents conductive energy loss. Insulation should be protected by a vapor retarder/barrier if it is not closed-cell. Closed-cell insulations can act as their own vapor retarder/barrier. The vapor retarder/barrier should be on the warm- in-winter side of the assembly. In climate zones 3 and 4 no vapor retarder/ barrier is required. See next slide.
5 Vapor Barrier: Prevents warm, humid air from reaching a cold surface where it can be cooled (maybe) to the dew point and condense on vulnerable surfaces. On the warm side of the insulation (inside in northern climates, none in moderate climates, outside in southern climates). Never two vapor barriers! Progressive permeance.
13 Details for the Building Enclosure – Air and Water Layers PRINCIPLES Five Control Layers 1. Rainscreen
Rain Penetration Forces
• Kinetic Energy
• Surface Tension
• Gravity • Capillarity • Air Pressure
Take - Home Messages
Two-stage weather-tightening is the only reliable way to provide weather-tight walls. 3/8” Use veneers with drainage planes behind (cavity walls). Often called rainscreen walls.
The drainage plane is CRITICAL. Attention to the details is as important as ever (75% of construction litigation is for leaks). Build a “boat” out of membranes. Problem Solution 14 Details for the Building Enclosure – Air and Water Layers PRINCIPLES ASHRAE 90.1 Air Barrier Requirements Five Control Layers for Commercial Buildings 2. Air Barriers
Penetrations are Fenestration Note this a serious perimeters requirement; it is It is clear that problem: we see are also a the Architect’s job it is VERY too many projects perennial to design how this important that not in compliance problem is done! Air barriers be continuous. with this section
15 Details for the Building Enclosure – Air and Water Layers PRINCIPLES 2015 IECC Air Barrier Requirements for Five Control Layers Commercial Buildings 2. Air Barriers
Continuous noted AGAIN!
16 Details for the Building Enclosure – Air and Water Layers PRINCIPLES IECC Air Barrier Requirements for Five Control Layers Commercial Buildings 2. Air Barriers
Continuous noted yet AGAIN!
17 Details for the Building Enclosure – Air and Water Layers PRINCIPLES Air Barrier Membranes Five Control Layers
History 2. Air Barrier and The intentional use of air barriers in North 3. Drainage Plane America began with the Canadians. Wagdy (usually the same) Anis, a Boston architect, promoted their use and almost single-handedly introduced them into the building codes. In a parallel Screw Penetrations development, Thompson & Lichtner pioneered the use of air barrier membranes at Rowes We have tested the water tightness of screw Wharf in Boston in 1987. A rubberized asphalt penetrations through rubberized asphalt membrane was used, which the manufacturer membranes, which are often promoted as self- sold for use as waterproofing. Since then, air healing. Although self-healing with punctured barrier membranes have evolved from this penetrations, such as nails, we find that membrane into a whole industry. screws eat up the membrane and do not
create watertight penetrations. Current Membranes The critical first criterion for weather barrier Gaskets behind the screw head on a tie, anchor, membranes is that they be adhered to the or girt is often promoted at a method of sealing backup wall. Our current preferred membranes these penetrations. Sealing at this location is not for air barrier systems tend to be liquid-applied necessary. What IS necessary is to seal at the systems with rubberized asphalt transitions point of penetration of the membrane itself. (flashings).
18 Details for the Building Enclosure – Air and Water Layers PRINCIPLES Air Barriers Common Air Leakage Pathways
The complexity of this list indicates why it is better to achieve air tightness at the plane of the weather barrier
19 Details for the Building Enclosure – Air and Water Layers PRINCIPLES Five Control Layers The Perfect Wall 4. Thermal
The “Perfect Wall” concept was developed The structure should be protected because we centuries ago by the Norwegians and was don’t want it to get wet. Also, thermal bridges th rediscovered by the Canadians in the mid-20 cause energy loss and condensation problems. century and has been promoted here in the
U.S. by Dr. Joe Lstiburek of Building Science Corporation. We want the structure to be insulated; expansion and contraction are worse if the The basic components of walls are: structure structure isn’t insulated, leading to joints that and control layers (plus cladding and finishes). open up, tears in membranes, etc. The control layers are: So, the rainscreen, drainage plane, air barrier, - Rain control (see previous slide) insulation, and vapor barrier go on the outside - Water control (the most important) of the structure. - Air control - Vapor control The control layers are all relatively visible and - Thermal control therefore inspect-able. And there cannot be condensation in vulnerable areas because the In a Perfect Wall all five control layers are on design of a perfect wall limits any possibility of the outside of the structure. condensation to areas of the wall designed to accommodate moisture.
Note that the Perfect Wall laid horizontally becomes the Perfect Floor or Perfect Roof.
20 Details for the Building Enclosure – Air and Water Layers
The Perfect Wall, continued
Some (including Lstiburek) have used the OUTER surface of the insulation as the water control layer by using tapes at the joints in the insulation. T&L believes the top edge of horizontal tapes needs to be sealed. When there is a slight curl in the upper edge where it has not been well rubbed-in, water accumulates and, over time, the tape gets pulled off of the wall. We often find tapes at the bottom of the cavity when doing testing and forensic work.
Image courtesy of ECHOtape
21 Details for the Building Enclosure – Air and Water Layers PRINCIPLES Too much Five Control Layers insulation in stud cavity? 4. Thermal (more than 50% of R- Balanced / Hybrid Walls value) Balanced / hybrid walls are walls where there is insulation both inside and outside of the weather- resistive barrier and the amount of interior insulation is held below the limit that can cause condensation Will this on the inside face of the sheathing, thereby avoiding void be the need for an interior vapor barrier and the filled with complications that entails. The limit is about 40% of insulation the total R-value for the wall for Zone 5 for normal and cause humidity occupancies. The % is more for Zone 6, unbalanced and somewhat less (25%) for Zone 4 and even less condition? for Zones 1-3.
These walls allow the use of vapor-retarding weather barriers, avoiding any concern with moisture-storing claddings that moisture might be driven inwards on sunny days by avoiding the need for interior vapor retarders and their restrictions on drying.
The Code allows this; it says that a vapor retarder is not required in cases where, “moisture or freezing will not damage the materials.“ 22 Details for the Building Enclosure – Air and Water Layers
Continuous Conventional Walls insulation (c.i.)
minimum R- Conventional walls are walls where there is 3.8 in insulation both inside and outside of the weather- Zones 1-4 and resistive barrier and the amount of interior 5, except insulation is not held below the limit that can Group R cause condensation on the inside face of the
sheathing, thereby requiring an interior vapor c.i. minimum barrier. R-7.5 for
Group R in These walls require the use of vapor-permeable Zone 5 and weather barriers, creating concern with moisture- Marine 4 and storing claddings that moisture might be driven in Zones inwards on sunny days. above 5
Cladding Rigid or semi-rigid insulation (extruded polystyrene –beware of NFPA 285- or mineral wool, but not polyisocyanurate) Weather barrier (vapor permeable) Sheathing (plywood or fiberglass-faced silicone impregnated gypsum) Dense-pack cellulose or open-cell spray foam or closed-cell spray foam (interior vapor barrier may be omitted with the latter) 23 Interior gypsum board
Details for the Building Enclosure – Air and Water Layers PRINCIPLES Five Control Layers 4. Thermal
Code Requirements for Insulation
Balanced Wall suggests having at least 40-50% of the insulation as continuous insulation in Zone 5,
24 Details for the Building Enclosure – Air and Water Layers PRINCIPLES Five Control Layers 4. Thermal Issues with Increased Insulation Joe Lstiburek from BSI-028: Decreased Heat Flow Due to Higher Insulation Levels Will Lead “Highly insulated building to Moisture Problems (Corrosion, enclosures with reduced heat gain Staining, Mold, Rot, etc.) have low drying potentials and increased interior moisture loads. When they get wet they don’t dry. Consequently, we need to exercise Stuff is beginning to stink, rot, break greater care in design and and annoy.” construction.
And, “Insulate on the outside. Back See Building Science Corporation ventilate and drain your cladding. BSI-028 (www.buildingscience.com ). Separate your sensible load from you latent load. Don’t over ventilate. Existing buildings are going to be a bear.”
25 Details for the Building Enclosure – Water and Air Control Layers
MEMBRANES
26 Details for the Building Enclosure – Water and Air Control Layers MEMBRANES Drainage Plane Systems Drainage Planes Use fluid-applied membranes. Use vapor-barrier membranes only when Acceptable Alternative: there is no insulation in the stud cavity #30 asphalt-saturated felt (or two layerss (or a “balanced wall”). Use vapor- of #15) as drainage plane. permeable membranes if there is a Joints in sheathing sealed as air barrier. vapor barrier on the interior. Be careful; with moisture-storing claddings. #15 asphalt felt is not a vapor retarder (about 5 perms). Also, once asphalt felt gets In Zones 3 and 4 with moisture-storing wet, its permeance increases (to about 20 – claddings such as brick veneer, avoid 60 perms) -- which is a good thing. That conventional walls. means a wet wall can dry out through the For both permeable and non-permeable now very permeable layer of asphalt felt. membranes, use self-adhered membrane The least preferred acceptable flashing for the transition to windows, alternative: the new systems that tape doors, etc. Seal all penetrations. the sheathing joints to achieve the air
barrier and drainage plane. As noted earlier, Do not rely on metal flashings for water T&L believes the top edge of the horizontal tightness; use membranes. Build a “boat” tapes need to be sealed. Also, the coatings out of membranes. Use metal or other on the face of these systems can be too thin materials to protect those membranes. to prevent damage during construction. 27 Details for the Building Enclosure – Air and Water Layers MEMBRANES Housewraps Do NOT use housewraps and similar un-adhered sheet materials to provide the drainage plane or air or water leakage protection. Problems with housewraps:
1.Not self-sealing around even puncture- type fasteners. Housewraps and similar sheet materials CAN successfully provide 2.Not bonded to substrate – water can secondary drainage planes in front of travel laterally, until it finds a way into the mineral wool or polyiso insulation in the building. veneer cavity.
3.Because they are not bonded to the substrate, they, “make their own water,” For open-jointed cladding systems, which is to say that humid air can get these sheets need to be ultra-violet between the housewrap and the wall, not resistant. having even the approximately R-1 value of the sheathing. Hence condensation occurs which would not otherwise take place.
28 Details for the Building Enclosure – Water and Air Control Layers
WOOD-FRAME
29 WF Details for the Building Enclosure – Water and Air Control Layers WOOD-FRAME Walls Low Performance
Vapor Barriers: Vapor barriers should not be used in Zones 3 & 4. This is typical for all slides that follow.
Air Barriers: Two air barriers are SECTION necessary to keep air currents from going through the batt insulation or causing wind- washing. One is on the interior (the drywall, often called the airtight drywall approach) Studs must be and one is on the exterior (the sheathing). 6” with R-20 insulation, per Airtight outlet Energy Code Housewrap is boxes are very NOT hard to find and recommended; PLAN hard to install see slide 37 airtight and must be used in future for alterations30 R Details for the Building Enclosure – Water and Air Control Layers WOOD-FRAME Walls Low Performance Control Layers
Note that fiberglass insulation can be compromised, due to the risk of convective loops which cause wind-washing and heat loss and might bring warm humid air up against cold surfaces with consequent risk of SECTION condensation.
Note that for all wood frame walls, plywood is shown, rather than OSB. Plywood has the ability to increase its permeance as it gets wetter, allowing it to dry out if it gets wet. This makes it a much more resilient material.
This system assumes that the air barrier can be achieved using the airtight drywall approach, which is difficult to achieve. In PLAN addition, the sheathing joints need to be sealed to make them airtight due to the open-cell batt insulation and possible wind- washing. 31 WF Details for the Building Enclosure – Water and Air Control Layers WOOD-FRAME Walls Medium Performance Flash and Batt or Blow
Note that Class III (latex paint) vapor retarder may be used and the airtight drywall VAPOR BARRIER approach does not have to be used, because the spray foam SECTION prevents warm, humid air from reaching the cold backside of the sheathing.
Studs must be 6” with R-20 For all systems that do not provide an air barrier at the sheathing plane, the airtight insulation, per drywall approach should be used and the Energy Code top and bottom plate need to be sealed and the rim joist area should be treated the same way as the wall. This is difficult PLAN to accomplish consistently in the field and is a common source of air leakage and heat loss. 32 WF Details for the Building Enclosure – Water and Air Control Layers WOOD-FRAME Walls Medium Performance Flash and Batt or Blow Control Layers
With flash and batt/blow design, the closed-cell insulation prevents the vapor- laden air in the interior from SECTION reaching the inside face of sheathing, thereby avoiding the need for a vapor barrier. This design can be used for a cathedral ceiling using flash and batt/blow there, too. The vapor barrier could be foil- faced gypsum board, as long as an air seal is provided at outlets, etc..
PLAN NOTE: With closed-cell foam separate vapor barrier is not needed; it is its own vapor barrier. With open-cell foam, vapor 33 WF barrier is needed inside of fiberglass insulation. Details for the Building Enclosure – Water and Air Control Layers WOOD-FRAME Walls Rainscreen Siding
Note: can be used with all of the wood frame wall designs shown.
Vents at bottom (shown) and top
Shiplap joint
Seal between sheathing and concrete; all walls 34 WF Details for the Building Enclosure – Water and Air Control Layers WOOD-FRAME Walls Higher Performance Ventilated Wall
Ventilation is desirable, but not essential SECTION
Studs must be 6” with R-20 insulation, per Energy Code
If cellulose is PLAN used (cellulose is not an air 35 WF barrier) Details for the Building Enclosure – Water and Air Control Layers WOOD-FRAME Walls Higher Performance Ventilated Wall Control Layers
Top of cladding open to vent (not shown); baffle against wind- VAPOR BARRIER driven rain with SECTION flashing and with insect screening
Inner air barrier hard to achieve, but it prevents convection currents, which can bypass the vapor PLAN barrier and negate the (DRYWALL AND SHEATHING) value of insulation. 36 WF Details for the Building Enclosure – Water and Air Control Layers WOOD-FRAME Walls High Performance Ventilated Wall with Continuous Insulation
Ventilation is desirable, but not essential
VAPOR BARRIER AND INSULATION – CLOSED CELL No Vapor Barrier with POLYURETHANE FOAM – SKIP VAPOR BARRIER BEHIND GWB Balanced Walls: This design works in Zone 5 as long as the R-value c.i. SECTION of the extruded polystyrene insulation is greater than the R-value of open cell foam, batt, or cellulose insulation in the stud cavity. PLAN R 15: 3” 3-1/2”: maximum R13 fiberglass batt or cellulose
37 WF Details for the Building Enclosure – Water and Air Control Layers WOOD-FRAME Walls High Performance Ventilated Wall with Continuous Insulation Control Layers
Note: Some use taped insulating sheathing instead VAPOR BARRIER AND SECTION INSULATION – CLOSED CELL POLYURETHANE of the extruded polystyrene in FOAM – SKIP VAPOR BARRIER BEHIND GWB this detail. We are concerned about the durability of the tape in that approach and the possibility of wetting the foam sheathing, which is not closed-cell. It could be made to work if the top edge of the tape is sealed with sealant. PLAN
38 WF Details for the Building Enclosure – Water and Air Control Layers
OPAQUE WALLS
39 Details for the Building Enclosure – Air and Water Layers
DETAILS Veneer Walls Brick Veneer ISOMETRIC
Veneer Walls Brick Veneer
ISOMETRIC
Note that a metal panel veneer is designed in much the same way; the connections to the backup wall are different but the other components are similar.
Isometric of Brick Veneer Wall* *Drawing developed at Shepley Bulfinch Richardson and Abbott and drawn by The Stubbins Associates 40 Details for the Building Enclosure – Air and Water Layers
DETAILS COMMERCIAL Veneer Walls Veneer Walls Brick Veneer Brick Veneer ISOMETRIC ISOMETRIC Control Layers If using mineral Control Layers wool insulation either add a permeable drainage plane Provide an air that is also a outside of the vapor barrier with moisture- insulation or slope storing claddings (e.g. all ledges brick); avoid an interior vapor barrier in such assemblies. If use insulation inside of the drainage plane, use Balanced Wall approach
Isometric of Brick Veneer Wall with Concrete Block Backup* *Drawing developed at Shepley Bulfinch Richardson and Abbott
41 Details for the Building Enclosure – Air and Water Layers DETAILS Veneer Walls Sheathing
Common problem; overdriven fastener; structural issue. If not repaired, requires filling with urethane sealant before membrane can be installed
42 Details for the Building Enclosure – Air and Water Layers DETAILS Veneer Walls Sheathing
Common problem; spacing of fasteners exceeds manufacturer’s recommendations. Structural issue
43 Details for the Building Enclosure – Air and Water Layers DETAILS Veneer Walls Drainage Plane
Common problem; fishmouths that extend to a seam are particularly worrisome
44 Details for the Building Enclosure – Air and Water Layers DETAILS Veneer Walls Drainage Plane
Common problem;Sealant cannotsealant repaircannot severe repair fishmouthssevere fishmouths
45 Details for the Building Enclosure – Air and Water Layers DETAILS Veneer Walls Drainage Plane
Common problem; undetailed penetrations (often by MEP trades); structural cable above, tubing at right
46 Details for the Building Enclosure – Air and Water Layers DETAILS Veneer Walls Insulation
Mineral wool; used more frequently to avoid issues with fire test performance. Note that foam plastic insulation can usually pass NFPA 285 when behind Note that there are masonry; could have no fasteners for used foam plastic the insulation insulation here other than the brick ties, which have been sealed (see next slide) 47 Details for the Building Enclosure – Air and Water Layers DETAILS Veneer Walls Drainage Plane
Brick tie without sealant
Brick tie with sealant in WRONG location. Head of fastener is NOT where penetration is. Sealant should surround fastener behind vertical plate of anchor and membrane
48 Details for the Building Enclosure – Air and Water Layers DETAILS Veneer Walls Brick Veneer Relieving Angle Brackets
Note relieving angle held off from wall to Note membrane allow room for has not been rolled- continuous in. It will need to be insulation behind replaced because atmospheric dust will have contaminated the adhesive 49 Details for the Building Enclosure – Air and Water Layers DETAILS Veneer Walls Backup Brick Veneer Wall Relieving Angle
Seal at brackets is critical; see next slide for easier solution STEEL BRACKETS
EXPS Even if wall insulation is mineral wool (see previous 50 slide) Details for the Building Enclosure – Air and Water Layers DETAILS Veneer Walls Brick Veneer SEALANT Relieving Angle IF INSULATIO Easier and N IS MINERAL Preferred Solution WOOL ADD METAL FLASHING TO SUPPORT MEMBRAN E
STEEL BRACKE TS EXPS Even if overall wall insulation is mineral wool
Backup Wall
51 Details for the Building Enclosure – Air and Water Layers DETAILS Veneer Walls Brick Veneer Relieving Angle Brackets – Seal
Note double bracket; not helpful, in that the gap between them could be a leak. If the “easier” solution for relieving angle is used, this is no longer an issue and all this sealant is not necessary
52 Details for the Building Enclosure – Air and Water Layers DETAILS Veneer Walls Brick Veneer Relieving Angle Insulation
Note the beveled mineral wool; ready to receive sloped through-wall flashing
But self-adhered membrane flashing will not adhere to mineral wool; must be EXPS or a metal flashing must be inserted to provide for adhesion (but that would be a thermal bridge 53 Details for the Building Enclosure – Air and Water Layers DETAILS Veneer Walls Brick Veneer Relieving Angle Flashing
Note sealant oozing out from behind anchor; good!
Note flashing slopes out over the insulation and then down over the vertical leg of the relieving angle
54 Details for the Building Enclosure – Air and Water Layers Commercial DETAILS version of relieving Veneer Walls angle Brick Veneer bracket Relieving Angle Brackets by HB Typically would be a membrane (air barrier / drainage plane) here
Still requires sealing at points where bolts penetrate membrane, which isn’t shown
55 DetailsJamb for flashingthe Building should Enclosure – Air and Water Layers have been installed DETAILS OVER butterfly; as shown, sealant needs Veneer Walls to be installed at edge Issues that bucks water Membranes
Butterfly joint at corner; the recommended detail
Housewrap NOT recommended
56 Details for the Building Enclosure – Air and Water Layers DETAILS Veneer Walls Issues SPF Insulation
Note that the spray polyurethane foam has bent the 1/8” aluminum tubular girts
Note: Installation of spray polyurethane foam requires a very experienced contractor using the best equipment to avoid installation issues
57 Details for the Building Enclosure – Water and Air Control Layers
FENESTRATION
58 Details for the Building Enclosure – Air and Water Layers PRINCIPLES Three Different Products, All Fenestration Fenestration Fenestration Types
Avoid stacked
Window (maximum size tested in lab by Avoid ganged manufacturer) Curtain Wall or Storefront Window (storefront cheap, low performance)
Window Wall is NOT a fenestration type! 59 Details for the Building Enclosure – Air and Water Layers DETAILS Fenestration Aluminum and Glass Curtain Walls TYPICAL MULLION
OUT IN
Curtain Wall Typical Mullion with Brick Veneer Wall Cladding* *Drawing developed by the Building Enclosure Council Chairs and drawn by Richard Keleher Architect
60 Details for the Building Enclosure – Air and Water Layers DETAILS Fenestration Aluminum and Glass Curtain Walls TYPICAL MULLION Control Layers
OUT IN
Curtain Wall Typical Mullion with Brick Veneer Wall Cladding* *Drawing developed by the Building Enclosure Council Chairs and drawn by Richard Keleher Architect 61 Details for the Building Enclosure – Air and Water Layers DETAILS Fenestration Aluminum and Glass Curtain Walls ISOMETRIC of System
Sealant will not work unless mullion is capped and support is from back of mullion (not a “T” or “F” anchor)! See next slide
Curtain Wall Isometric of System with Brick Veneer Wall Cladding* *Dwg developed by Building Enclosure Council Chairs & drawn by Richard Keleher 62 Details for the Building Enclosure – Air and Water Layers DETAILS Fenestration Aluminum and Glass Curtain Walls Typical Problem with Manufacturers’ Details
Sealant here (what manufacturers typically show) does not seal to the plane of air and water tightnes (see oval below and to left). Use a OUT IN membrane here, with backer rod supporting it
The plane of air and The vertical tubes (which run water tightness is thru) have structural openings here (red dashed line) in their sides. Also, they are open at top and bottom. If capped, cannot use “F” or “T” anchors 63 Details for the Building Enclosure – Air and Water Layers DETAILS Fenestration Aluminum and Glass Curtain Walls HEAD at Brick Veneer
See relieving angle details for options OUT IN
Applicable to all curtain wall details; fillet bead of sealant (see blow up at jamb detail) at edge of air barrier Curtain Wall Head with Brick Veneer Wall Cladding* membrane *Drawing developed by the Building Enclosure Council Chairs and drawn by Richard Keleher Architect 64 Details for the Building Enclosure – Air and Water Layers DETAILS Fenestration Aluminum and Glass Curtain Walls HEAD at Brick Veneer Control Layers Use only vapor- permeable membrane with conventional walls
OUT IN Extruded silicone shown; could be self- adhered membrane flashing going right into the pocket as shown in slide 97 (no return inside). But would require protecting flap of Curtain Wall Head with Brick Veneer Wall Cladding* membrane left *Drawing developed by the Building Enclosure Council Chairs and drawn by Richard Keleher Architect exposed while brick 65 is installed Details for the Building Enclosure – Air and Water Layers DETAILS Fenestration Aluminum and Glass Curtain Walls HEAD at Metal Panels
Note membrane into glazing pocket
OUT IN
66 Details for the Building Enclosure – Air and Water Layers DETAILS Fenestration Aluminum and Glass Curtain Walls HEAD at Metal Panels Control Layers
Use only vapor- permeable membrane with conventional walls
OUT IN
67 Details for the Building Enclosure – Air and Water Layers DETAILS Fenestration Aluminum and Glass Curtain Walls JAMB at Brick Veneer
Provide insulation here to prevent condensation on back of membrane OUT IN
Curtain Wall Jamb with Brick Veneer Wall Cladding* And up to *Drawing developed by the Building Enclosure Council Chairs and drawn by Richard Keleher Architect 50% R-value (climate zone 5) here 68 Details for the Building Enclosure – Air and Water Layers DETAILS Fenestration Aluminum and Glass Curtain Walls JAMB at Brick Veneer Control Layers
OUT IN Use only vapor- permeable membrane with conventional walls
Curtain Wall Jamb with Brick Veneer Wall Cladding* *Drawing developed by the Building Enclosure Council Chairs and drawn by Richard Keleher Architect 69 Details for the Building Enclosure – Air and Water Layers DETAILS Fenestration Aluminum and Glass Curtain Walls JAMB at Metal Panel IN OUT
Sealant would be a better solution from a weatherproofing perspective, due to the difficulty of sealing all of the joints in the metal angle
70 Details for the Building Enclosure – Air and Water Layers DETAILS Fenestration Aluminum and Glass Curtain Walls JAMB at Metal Panel Control Layers IN OUT
Use only vapor- permeable membrane with conventional walls
71 Details for the Building Enclosure – Air and Water Layers DETAILS Fenestration Aluminum and Glass Curtain Walls SILL at Brick Veneer
OUT IN Typical: Horizontal surfaces should be sloped to the outside; it is hard to find systems that do this
The reason for sloping is that most sealants are damaged by standing water; the Curtain Wall Sill with Brick Veneer Wall Cladding* sealants at the *Drawing developed by the Building Enclosure Council Chairs and drawn by Richard Keleher Architect ends and corners will be affected 72 Details for the Building Enclosure – Air and Water Layers DETAILS Fenestration Aluminum and Glass Curtain Walls SILL at Brick Veneer Control Layers OUT IN
Use only vapor- permeable membrane with conventional walls
Curtain Wall Sill with Brick Veneer Wall Cladding* *Drawing developed by the Building Enclosure Council Chairs and drawn by Richard Keleher Architect 73 Details for the Building Enclosure – Air and Water Layers DETAILS Fenestration Aluminum and Glass Curtain Walls Zone Dams and Screw Heads
Screw head sealed
Zone dam sealed. Tooling is neat
74 Details for the Building Enclosure – Air and Water Layers DETAILS Fenestration Aluminum and Glass Curtain Walls Pressure Plates
Groove at bottom of setting block allows drainage to weeps Joint between two pressure plates is sealed
75 Details for the Building Enclosure – Air and Water Layers DETAILS Fenestration Aluminum and Glass Curtain Walls Pressure Plates
Pressure plates are sealed together Cap installed and sealed
76 Details for the Building Enclosure – Air and Water Layers DETAILS Fenestration Aluminum and Glass Zone Curtain Walls dam sealed Vertical Corner
Screw head sealed
Membrane continues from behind brick veneer, into the glazing pocket
77 Details for the Building Enclosure – Air and Water Layers DETAILS Fenestration Aluminum and Glass Curtain Walls Vertical Corner Membrane sealed to face of precast concrete (a barrier wall, not a veneer) Sealant neatly troweled over extruded silicone membrane
Membrane not tooled and sealed to precast at top and bottom
78 Details for the Building Enclosure – Air and Water Layers DETAILS Fenestration Dashed red lines are self- Windows, Louvers, Doors adhered membrane flashing HEAD at Brick End dam at 1st joint after opening
LiquiSealant
BACKER ROD TO SUPPORT MEMBRANE OUT BETWEEN ANCHOR CLIPS IN
SPRAY POLYURETHANE FOAM
Window Head Detail at Brick Veneer* These window details *Drawing developed by the Building Enclosure Council Chairs and drawn by the Façade Group are available at http://www.wbdg.org/d esign/env_fenestratio 79 n_win.php Details for the Building Enclosure – Air and Water Layers DETAILS Fenestration Windows, Louvers, Doors HEAD at Brick Control Layers
Use only vapor- permeable membrane with conventional walls
OUT IN Typical for all non-flanged window details; provide end plug or angle at ends of vertical mullions to support backer rods
Window Head Detail at Brick Veneer* For Whole Building Envelope *Drawing developed by the Building Enclosure Council Design Guide, go to: Chairs and drawn by the Façade Group http://www.wbdg.org/design/e nvelope.php 80 Details for the Building Enclosure – Air and Water Layers DETAILS Fenestration Windows, Louvers, Doors JAMB at Brick
IN
BACKER ROD
SPRAY POLYURETHANE FOAM
Window Jamb Detail at Brick Veneer* *Drawing developed by the Building Enclosure Council Chairs and drawn by the Façade Group OUT
81 Details for the Building Enclosure – Air and Water Layers DETAILS Fenestration Windows, Louvers, Doors JAMB at Brick Control Layers
Use only vapor- IN permeable BACKER ROD membrane with conventional walls
Typical Note for all window details; heel bead of sealant continues air barrier past snap-in glazing bead. Will help prevent air leakage and Window Jamb Detail at Brick Veneer* *Drawing developed by the Building Enclosure Council Chairs and drawn by possible condensation the Façade Group OUT
82 Details for the Building Enclosure – Air and Water Layers DETAILS Fenestration Windows, Louvers, Doors SILL at Brick
BACKER ROD OUT IN
MINERAL WOOL
Subsill flashing an option if anchored differently. Anchor thru upturned back leg
Window Sill Detail at Brick Veneer* *Drawing developed by the Building Enclosure Council Chairs and drawn by the Façade Group
83 Details for the Building Enclosure – Air and Water Layers DETAILS Fenestration Windows, Louvers, Doors SILL at Brick Control Layers
BACKER ROD OUT IN Heel bead of sealant prevents air leakage (snap- in glazing bead is NOT airtight – gaps at ends, etc.). Be sure setting blocks allow continuity of sealant and still support the inner lite. Glazing pocket must be weeped or there is likely voiding of IGU manufacturer’s warrantee.
Window Sill Detail at Brick Veneer* *Drawing developed by the Building Enclosure Council Chairs and drawn by Use only vapor- the Façade Group permeable membrane with conventional walls 84 Details for the Building Enclosure – Water and Air Control Layers DETAILS Weather barrier Fenestration flashing Flanged Windows wrapped HEAD into opening Sealant here unless you are sure that the foam at jambs and head is airtight and makes an airtight seal to sealant at sill. Typical all flanged window details
SPRAY FOAM Sealant at edge of membrane. Typical all flanged window details Flanged window details similar for c.i. 85 WF Details for the Building Enclosure – Water and Air Control Layers DETAILS Openings Flanged Window Miter corner Receptors
Miter or cope flanges Flanged or nail-fin windows allow excellent integration with the air barrier.
It is important that the flanges/nailing fins be integral with the window and have Receptor mitered or coped – see corners. slide 138 86 WF Details for the Building Enclosure – Air and Water Layers Flanged windows are now seeing increased use in commercial DETAILS construction, due to the better integration with the air barrier. Fenestration Constraints have to do with finding higher-quality windows with Flanged Windows integral flanges/nailing fins that have mitered corners HEAD at Metal Panels
OUT IN
BACKER ROD TO SUPPORT MEMBRANE
87 Details for the Building Enclosure – Air and Water Layers DETAILS Fenestration Flanged Windows HEAD at Metal Panels Control Layers
insulation OUT drainage plane IN Use only vapor- permeable membrane with conventional walls
88 Details for the Building Enclosure – Air and Water Layers DETAILS Fenestration IN Flanged Windows Bead of JAMB at Metal Panels sealant at edge of membrane, SEALANT & BACKER ROD typical, jambs only
WINDOW – FLANGED JAMB AT METAL PANEL OUT
89 Details for the Building Enclosure – Air and Water Layers DETAILS Use only vapor- Fenestration permeable Flanged Windows membrane with IN JAMB at Metal Panels conventional walls
insulation
WINDOW – FLANGED JAMB AT METAL PANEL OUT
90 Details for the Building Enclosure – Air and Water Layers DETAILS Fenestration OUT IN Flanged Windows SILL at Metal Panels
SEALANT & BACKER ROD
SPRAY POLYURETHANE FOAM
WINDOW – FLANGED SILL AT METAL PANEL
91 Details for the Building Enclosure Run– Air sealant and Water Layers at least six DETAILS inches up Fenestration OUT jambs*IN Flanged Windows SILL at Metal Panels Control Layers
This is what the Join to sealant foam at jambs at jambs to must make an create sill pan airtight seal with
SPRAY POLYURETHANE FOAM
insulation
Use only vapor- permeable membrane with WINDOW – FLANGED SILL AT METAL conventional walls PANEL
92 Details for the Building Enclosure – Water and Air Control Layers DETAILS Openings Flanged Windows Example at Building Paper
Joints in plywood sealed one-part urethane sealant (air barrier)
Building paper (#30 asphalt- saturated felts) (drainage Self-adhered plane) butyl (could be rubberized asphalt) flashing 93 WF Details for the Building Enclosure – Water and Air Control Layers DETAILS Openings Flanged Windows Example at Building Paper
Tape used to prevent water Note flange left from travelling un-taped for laterally at Membrane drainage joints should be (optional) rolled-in!!!
94 WF Details for the Building Enclosure – Air and Water Layers DETAILS Openings Flanged Windows SILL - Outside Jamb Example of Butterfly flashing still to be installed
Sill flashing turned up on jamb
Butterfly
Note: this was a mockup; wall membrane should be installed first 95 WF Details for the Building Enclosure – Air and Water Layers DETAILS Openings Flanged Windows and Wall Construction Example at Fluid- Applied Membrane with Polyiso Insulation and Furring First layer of flashing Tape over flashing
Sealing a penetration Insulation with sealant at Furring being installed points of fastening furring
96 Details for the Building Enclosure – Water and Air Control Layers DETAILS Openings Sealant may Flanged Windows continue up the SILL - Inside jambs and across Example the head to Membrane complete the air flashing should barrier (robust be turned up solution), or spray higher (6” min.) foam can be used for high wind above six inches locations
Sealant at sill is Self-adhered butyl the air and (could be rubberized water barrier asphalt) flashing. Self- and turns adhered membrane minimum six Extra could be used instead inches up the of sealant noted jambs. membrane inside of elsewhere sealant is not required 97 WF Details for the Building Enclosure – Air and Water Layers DETAILS Fenestration Storefronts SILL OUT IN Seal between storefront and upturned leg of END DAM WEEP flashing THERMALLY BROKEN SUB SILL Self-adhered
STUFF WITH membrane flashing MINERAL WOOL back-wrapped onto upturned leg of metal flashing
Storefront head and jamb details are similar to un-flanged CONTINUOUS window head and CLEAT Angle support jambs. But sill avoids screw requires sill pan, *Drawing developed at Shepley Bulfinchpenetration Richardson and carefully installed Abbott and drawn by The Stubbins Associatesthrough sill and sealed because flashing storefronts drain internally 98 Details for the Building Enclosure – Air and Water Layers DETAILS Fenestration Storefronts SILL – Control Layers
OUT IN
Note: Storefronts are inherently less energy-efficient due to air leakage and are prone to water leakage
*Drawing developed at Shepley Bulfinch Richardson and Abbott and drawn by The Stubbins Associates
99 Details for the Building Enclosure – Air and Water Layers Sill pan with end DETAILS dams & no penetrations - Fenestration fasten thru Weep Storefronts vertical leg glazing SILL - Recessed pocket OUT IN Weep sill, per manufacturer’s instr.
Weep sealant 24” o.c.
Seal between storefront Snow guards and upturned leg of may be metal flashing. Use clip necessary with angles to anchor the shallow slopes *Drawing by Donham & Sweeney storefront, added after and sills over installation of membrane 4” deep flashing 100
Details for the Building Enclosure – Air and Water Layers DETAILS Fenestration Storefronts SILL – Recessed
DRAINAGE PLANE HERE, TOO Control Layers OUT IN
*Drawing by Donham & Sweeney
101 Details for the Building Enclosure –Sealant Air and is thickWater Layers because the DETAILS storefront will Fenestration be set into it Storefronts Storefront Sill SILL - Issues
End dam on storefront sill pan Card indicates no sealant at back dam Sealant at Thermal left, none break at right
102 Details for the Building Enclosure – Air and Water Layers DETAILS Fenestration Storefronts Storefront Sill SILL - Issues
Sill, outside Even if all of the Sill, end dam aforementioned joints are sealed, if this (exterior) Note gap joint is not sealed, water in end may overwhelm the dam drainage capacity of the weep holes at the sill
103 Details for the Building Enclosure – Air and Water Layers DETAILS Fenestration Storefronts Storefront Sills SILL - Issues Still an unsealed opening
Outside of storefront after installation. Sill, end dam This end dam is sealed well 104 Details for the Building Enclosure – Air and Water Layers DETAILS Fenestration Storefronts Storefront Sill and Head HEAD and SILL - Issues
Rough opening with membrane, which is Head receptor air barrier, drainage plane, and vapor barrier Note the Note gap at neatly end of gasket tooled (shrinkage sealant issue) 105 Details for the Building Enclosure – Water and Air Control Layers DETAILS Fenestration Windows, Louvers, Doors Storefronts and Windows SILL – Issues - Receptors
Nailing flange should be coped as shown for flanged windows
Note: windows and storefronts are often used with receptor systems. These are problematic, and offer another whole set of potential leakage paths for both air and water.106 Details for the Building Enclosure – Air and Water Layers GENERAL Fenestration Fenestration Performance Performance & Quality Assurance Air Leakage: The required performance should be <0.1 cfm/sf Quality Assurance @ 6.24 psf (<0.15 in the field) and be as needed to meet the energy Field test several installed units to confirm performance goals of the project. fenestration performance and to test the
flashings and sealants. Receptors and Water Test: The required panning should be included in field tests. performance should be adjusted to
suit the expected exposure; higher For every failed test, the contractor buildings, flat terrain, coastal location should be required to [pay for testing two require higher performance. additional units, in addition to repairing Ganged and Stacked Windows are and re-testing the failed units until they not recommended, unless the pass. ganged / stacked joints have been laboratory tested and meet the The specifications should specifically state performance standards of the project. that the AAMA allowed 1/3 reduction in performance will not be allowed or the specified performance should be increased by 1/3 to allow for this. 107 Details for the Building Enclosure – Water and Air Control Layers
ROOFS
108 Details for the Building Enclosure – Air and Water Layers COMMERCIAL Roofs Veneer Wall Issues
Common problem; no detail provided to show how the roof edge will be terminated. Also, this membrane does not join the air (and vapor) barrier in the wall
109 Details for the Building Enclosure – Air and Water Layers COMMERCIAL Roofs Curtain Issues
Common problem; no details provided to show how the parapet meets adjacent curtain wall
110 Details for the Building Enclosure – Air and Water Layers COMMERCIAL Roofs Low-Slope Roof Wall/Roof Brick Veneer
Roofing goes over parapet, turns down and is sealed to weather barrier. Verity compatibility between roofing and air barrier
Closed-cell foam or vapor AVB goes Brick Veneer Wall/Low-Slope Roof Detail with Parapet* barrier at up to here *Drawing developed at Shepley Bulfinch Richardson and Abbott and drawn by Thedeck Stubbins Associates 111 Details for the Building Enclosure – Air and Water Layers COMMERCIAL Roofs Low-Slope Roof Wall/Roof Brick Veneer Control Layers The vapor barrier is often omitted on steel deck (except for high- humidity occupancies and with mechanically attached membranes, in which case the vapor barrier must also be an air barrier). Always use a vapor barrier on new concrete decks. If a vapor barrier is used, include a leak detection system to avoid overloading with retained water in the event of a leak. If vapor barrier is omitted, the roof membrane must be treated as the air barrier
Brick Veneer Wall/Low-Slope Roof Detail with Parapet* Air and vapor barrier *Drawing developed at Shepley Bulfinch Richardson and Abbott and drawn by The Stubbins Associates For conventional walls, the vapor here, to keep vapor out barrier belongs on the inside of the of the parapet or use wall and the flutes of the floor deck closed-cell foam in the 112 should be foamed parapet, as shown Details for the Building Enclosure – Air and Water Layers COMMERCIAL Roofs Low-Slope Roof Wall/Roof Metal Panel
Red line: Connect roof membrane to wall membrane.
Overlap minimum
2” (shingle to shed water) and seal ROOFING MEMBRANE UNDER WALL MEMBRANE
MINIMUM 2”
8” MINIMUM MINIMUM 8” IN NEWENGLAND
RIGID INSULATION
113 Details for the Building Enclosure – Water and Air Control Layers
INSPECTION AND TESTING
114 Details for the Building Enclosure – Air and Water Layers GENERAL Inspection Field Inspection 1
115 Details for the Building Enclosure – Air and Water Layers GENERAL Inspection Field Inspection 2
Common problems
116 Details for the Building Enclosure – Air and Water Layers GENERAL Inspection Field Inspection 3
Weep should go down to flashing, otherwise dams water behind
117 Details for the Building Enclosure – Air and Water Layers GENERAL Testing 1 Fenestration Testing
Air leakage test Water leakage test
Performance testing of fenestration is important 118 Details for the Building Enclosure – Air and Water Layers GENERAL Testing 2 Roof Testing
Wind uplift test
Not done Is done very very often often Electronic roof and waterproofing testing – better than flood testing 119 Details for the Building Enclosure – Air and Water Layers GENERAL Summary
Summary of Key Concepts: • Manage Water, Air and Vapor • Continuity of control layers
Issues for Architects: • Compatibility of materials • Connection details Issues for Contractors: • Coordination between trades • Sequencing of the work • Quality Control - Is it done anymore? • Inspection • Testing
120 Details for the Building Enclosure – Water and Air Control Layers
References: Building Science for Building Enclosures by John F. Straube and Eric F. P. Burnett 2005 Building Science Press, Somerville, Massachusetts Designing the Exterior Wall by Linda Brock 2005 John Wiley & Sons, Hoboken, New Jersey High Performance Enclosures by John F. Straube 2012 Building Science Press, Somerville, Massachusetts The Whole Building Design Guide http://www.wbdg.org Building Envelope Design Guide (R. Keleher, editor) http://www.wbdg.org/design/envelope.php
121 QUESTIONS?
This concludes The American Institute of Architects Continuing Education Systems Course
Richard Keleher The Thompson & Lichtner Company [email protected] (617) 492-2111