chapter 8. DOOR AND FRAMES

8.1 GENERAL 8.1.1 Frames There are two basic types of door and and in the surrounding members is window frames: the traditional system of particularly troublesome. interlocking members and the integral-flange metal sections. Variations of 8.1.3 Installation of Membrane Around the latter include metal clad and plastic Door Sills coated, but they are similar in sections and Special attention should be paid to the dimensions and equal in performance. Also, jamb-sill corner at the door sill. This edge among the metal types are those designed condition, when not properly detailed, will to be installed in wood-frame and allow water penetration to the interior. those designed for concrete openings. (Figures 8-1A to 8-1G) illustrate the proper installation of felt membrane around a door We will not deal with those frames that are sill in a step-by-step manner. designed for concrete-type openings, except to mention that they are not intended (we hope) to be installed in wood-frame 8.2 WOOD FRAMES buildings. To use this type of section in To make a watertight frame head condition, wood-frame buildings is to invite disaster. two facts should always be remembered: If such installations are required, the water wants to run down hill, and wind designer must pay very close attention to will push it horizontally or up vertically. If the detailing. the designer keeps these facts in mind and makes provision for them, particulary at 8.1.2 Door Sills corners or intersections, the opening In general, door openings should be probably will perform well. Other important handled in the same way at the head and considerations are the following: jambs as are . Sills require somewhat different treatment. The sill 8.2.1 General portion of wood-frame door assemblies is 1. For general membrane sequence, see susceptible to water penetration and must membrane installation under general be correctly detailed. Sometimes door sills detailing (Chapter 3). are made from decay-resistant wood or metal, and are not susceptable to decay. 2. The jambs are between the head and However, water penetration under the sill sill, not the other way around. WOOD: DETAILING FOR PERFORMANCE

b Jamb framing

Subfloor

DOOR SILL DETAIL ASSEMBLY AT JAMB-SILL CORNER Figure 8-1A WOOD: DETAILING FOR PERFORMANCE chapter 8 - 3

DOOR SILL DETAIL ASSEMBLY AT JAMB-SILL CORNER Figure 8-1B chapter 8 - 4 WOOD: DETAILING FOR PERFORMANCE

Felt split sheet applied vertically around frame

- - -Felt split sheet - or plastic flashing ' - (preferable) I ', - I ' -

\ \ \ \ ' \

DOOR SILL DETAIL ASSEMBLY AT JAMB-SILL CORNER Figure 8-1C WOOD: DETAILING FOR PERFORMANCE chaoter 8 - 5

Felt left Ion for cIarnpin1 beqween trim & oor

Felt split sheet I applied vertically I I I Felt split sheet or preferably I ' plastic flashrng I I ', I I '' I I ',

DOOR SILL DETAIL ASSEMBLY AT JAMB-SILL CORNER Figure 8-1D chapter 8 - 6 WOOD: DETAILING FOR PERFORMANCE

DOOR SILL DETAIL ASSEMBLY AT JAMB-SILL CORNER Figure 8-1E WOOD: DETAILING FOR PERFORMANCE chapter 8 - 7

DOOR SILL DETAIL ASSEMBLY AT JAMB-SILL CORNER Figure 8-1F chapter 8 - 8 WOOD: DETAILING FOR PERFORMANCE

-Sill with sloped surface

DOOR SILL DETAIL ASSEMBLY AT JAMB-SILL CORNER Figure 8-1G WOOD: DETAILING FOR PERFORMANCE chapter 8 - 9

3. The trim holds the frame in place. The 3. Jamb trim should be tight to siding. In shims and frame nailing should only severe exposure locations, with shiplap function only to align and temporarily or other uneven surface siding, sealants place the frame. or gaskets can fill voids. 4. Allowance must be made for some shrinkage and swelling of members. 8.2.1.3 Sill 5. Allowance must be made for adequate 1. Portions of the sill exposed to the trim overlay on the frame to receive weather should slope at least 12 good nailing. In severe locations, degrees from horizontal. sealant may be advisable'for the joints. 2. Ends of the sill should project beyond 8.2.1.1 Head the opening over siding at least slightly more than the width of the jamb trim. 1. Carry the jamb membrane up and under head trim and membrane. 3. Ensure that the sill sets tight to the membrane. 2. Install metal flashing under head membrane and over head trim. Extend flashing over edge of trim and turn down one inch.

3. A gap between the metal flashing and 8.2.2 Wood Window in Panel the siding is desirable to avoid wetting Siding (Figures 8-2 to 8-4) and possible staining of the siding. Do The dimensions of the head flashing legs not seal this joint. depend on the use condition, but should be 4. See &tail, for typical condition (Figure at least the "A" dimension. A 318 inch gap 8-2). must be provided between the flashing and the plywood panel to avoid excessive 8.2.1.2 Jamb wetting of the plywood by capillary action, as water will collect at this flashing edge. 1. Turn the split sheet around the frame opening. Lap it over the sill sheet. The The jamb detail shown in Figure 8-3 will design should encourage exterior water protect the window opening from water drainage, if a leak develops. seepage from the side. In some cases, it 2. The membrane sheet should be carried may be necessary to terminate the plywood out and clamped between the jamb trim panel at the jamb over the center of a stud, and the frame. This joint must be tight so the adjoining plywood panel above and to avoid wind-induced water infiltra- below the window can be nailed into the tion. Remember to carry this membrane same stud. In these cases, the jamb trim up and under the ends of the head should be wide enough to cover over the trim. joint in the panel siding. chapter 8 - 10 WOOD: DETAILING FOR PERFORMANCE

EXTERIOR

Exterior head trim

Note: For "A" dimension see Table 3- 1 WOOD WINDOW DETAIL HEAD DETAIL IN PLYWOOD SIDING

Figure 8-2 WOOD: DETAILING FOR PERFORMANCE chapter 8 - 11

EXTERIOR

WOOD WINDOW DETAIL JAMB DETAIL IN PLYWOOD SIDING Figure 8-3 chapter 8 - 12 WOOD: DETAILING FOR PERFORMANCE

EXTERIOR

WOOD WINDOW DETAIL SILL DETAIL IN PLYWOOD SIDING Figure 8-4 WOOD: DETAILING FOR PERFORMANCE chapter 8 - 13

Wood window sills should cover panel impossible to give general guidelines that siding at least 314 inch to protect the will govern all conditions. However, having window opening from rain, as shown in said that, now let us try. At the risk of Figure 8-4. If a manufactured sill is used being repetitious; water wants to run down and does not provide a 314 inch overlap, hill and that wind will push it both flashing should be added at this joint. In horizontally and vertically. Pay attention wind-driven rain locations, it will be neces- and make provisions for this, particularly at sary to provide metal flashing because the corners and intersections. 314 inch lap is simply inadequate. In spe- 1. When possible, use units with welded cial cases, a trim member can be adequate, comers that have a continuous, if the wall membrane is well detailed. unbroken nailing flange. These units provide an easier task of keeping the 8.2.3 Elements of a Good Wood Door water out of the framing. Sill Detail Simply follow the guidelines set forth The wood door sill should be made from in membrane installation in Chapter 3. naturally decay-resistant wood or should be 2. When welded comers are not feasible, chemically treated. Adequate sill sections such as in sliding door units and other can be milled from clear vertical grain knockdown assemblies, other steps stock (see Figure 8-5 for a good sample must be taken: section). The sill should be cut so that it covers the exterior siding material by at least 314 inch. If the sill does not provide On the backside of the frame, apply such coverage, or if the sill is exposed to large, heavy globs of sealant severe environmental conditions, metal continuously along all metal-to-metal flashing should be used to protect the joint joints. This sealant must be applied from wind-driven rain. The underside of the to clean metal and must lap surfaces sill should be sloped downward at least 12 at least 318 inch to obtain good degrees; otherwise a drip cut should be adherence to both legs. Sealant must provided. To be effective, a drip cut must also have enough body to withstand be at least 114 inch wide by 114 inch deep. the racking of the frame during To further protect against wind-driven rain, installation, plus future movement. the felt membrane behind the siding mate- Sealant can also be used when rial should continue to run under the door nailing flanges are mitered. sill as illustrated. Figure 8-6 illustrates a poorly designed wood door sill section. When nailing flanges are notched (as in most door cases), a metal 8.3 METAL FRAMES comer piece set in sealant is the most foolproof. However, pressure- 8.3.1 General sensitive waterproof tape can also Because of the wide detail variation in do a good job. Again, allow lots of metal doors and windows, it is almost overlap of tape to metal. chapter 8 - 14 WOOD: DETAILING FOR PERFORMANCE

Sill made .from naturally decay res~stantwood or pressure treated

WOOD DOOR SILL RECOMMENDED SECTION

Figure 8-5 WOOD: DETAILING FOR PERFORMANCE chapter 8 - 15

Felt membrane not cont~nuedunder s~ll

WOOD DOOR SILL POOR PRACTICE

Figure 8-6 chapter 8 - 16 WOOD: DETAILING FOR PERFORMANCE

Sliding door sills often do not come the top of the head trim should be sloped with nailing flanges. When this and should extend to the outer edge of the occurs, metal flashing should be used, jamb trim. Lumber siding should be butted and it must be integrated with the against the head while it is covered by the jamb condition. Fastenings must be jamb trim. This avoids an open joint properly sealed. between the jamb trim and the siding, where the membrane will be exposed. As 8.3.2 Windows usual, drip cuts should be provided where needed, and all horizontal ledges should be Figure 8-7 illustrates the desirable sloped to aid drainage. characteristics of a good metal window with nailing flanges. The length of the flange should be "A" dimension (see Table 3-1 in Chapter 3). The horizontal ledges 8.3.3 Elements of a Good Metal Door should be sloped a minimum of 12 degrees. Sill Detail Weep slots and drip edges are also desirable to remove collected water. Extruded aluminum sills are good alternatives for wood sills because they are 8.3.2.1 Metal Window in Plywood Panel unaffected by moisture. From the many Siding (Figures 8-8 to 8-10) commercially available sections, sill sections with a longer "leg" on the exterior If trim is desired in a plywood panel side are preferable. This leg covers the system, it should be of a solid lumber upper edge of the exterior siding material stock (i.e., not plywood) and should be and protects this joint from wind-driven sloped on top at least 12 degrees. In addi- rain (see Figure 8-14). If a sill without a tion, sealant should be provided at the top leg is used, or if the leg covers less than of the trim to keep moisture away from the 314 inch of the exterior material, flashing inner surface in between the siding and the should be provided (see Figure 8-15). trim; this area is vulnerable to decay. Sill Figure 8-16 illustrates a poorly designed trim should also be sloped on the top sur- metal door sill detail. face and sealant applied to this area to protect against wind-driven rain that pushes Metal sills are usually fastened to the moisture over the edge of the panel and subfloor by long screws. The screw wets the backside. penetration holes are vulnerable points because they are not watertight. The felt 8.3.2.2' Metal Window in Lumber Siding membrane should be continuous under the (Figures 8-11 to 8-13) sill and extend beyond the screw holes. In a lumber siding system, flashing should be provided over the head trim. Optimally, WOOD: DETAILING FOR PERFORMANCE chapter 8 - 17

Head framing fin

1 " absolute min., 1 -1/2" preferred

I 1 Slope is highly desirable

P -Section should be flush at top. - i d

HEAD SECTION n U Outside section should slide

Height of rear sill leg important - - / for water resistance to wind - driven rain. Higher leg equais t- /- I better performance. /- I I +- J Weep slot should drcin to outer face and lead to drip edge.

Lip should be 3/4" to rotect top edge of siding maP erial

(I Sill framing fin SILL SECTION METAL WINDOW DETAIL DESIRABLE PROPERTIES OF A HORIZONTAL SLIDING WINDOW Figure 8-7 chapter 8 - 18 WOOD: DETAILING FOR PERFORMANCE

Wood trim at head

Space for drainage

The addition of a head flashing split EXTERIOR sheet, installed after the jamb flashing, will .provide extra assurance against water penetration at the head fin. METAL WINDOW DETAIL HEAD DETAIL IN PLYWOOD SIDING Figure 8-8 WOOD: DETAILING FOR PERFORMANCE chapter 8 - 19

EXTERIOR

Felt split sheet jamb flashing Felt

Siding

Wood trim at jamb

/i/ / '/ 111 I// / / //A I L L -

,- METAL WINDOW DETAIL JAMB DETAIL IN PLYWOOD SIDING Figure 8-9 chapter 8 - 20 WOOD: DETAILING FOR PERFORMANCE

EXTERIOR

Wood trim at sill

METAL WINDOW DETAIL SILL DETAIL IN PLYWOOD SIDING Figure 8-10 WOOD: DETAILING FOR PERFORMANCE chapter 8 - 21

Wood trim at head

EXTERIOR

METAL WINDOW DETAIL HEAD DETAIL IN LUMBER SIDING Figure 8-11 chapter 8 - 22 WOOD: DETAILING FOR PERFORMANCE

EXTERIOR

Wood trim at jamb

ealant and backer rod

METAL WINDOW DETAIL JAMB DETAIL IN LUMBER SIDING Figure 8-12 WOOD: DETAILING FOR PERFORMANCE chapter 8 - 23

EXTERIOR

METAL WINDOW DETAIL SILL DETAIL IN LUMBER SIDING Figure 8-13 chapter 8 - 24 WOOD: DETAILING FOR PERFORMANCE

Proper location for screws

METAL DOOR SILL DETAIL

Figure 8-14 WOOD: DETAILING FOR PERFORMANCE chapter 8 - 25

Location for screws set ~n sealant

METAL DOOR SILL DETAIL

Figure 8-15 chapter 8 - 26 WOOD: DETAILING FOR PERFORMANCE

N~s@l" F"CQ~ go , Door

METAL DOOR SILL DETAIL POOR PRACTICE

Figure 8- 16 chapter 8 - 26 WOOD: DETAILING FOR PERFORMANCE

N~~~" 1 F~~oph 1 Door

METAL DOOR SILL DETAIL POOR PRACTICE Figure 8-16