Waterproofing / a Roundtable Discussion

Hoffmann Architects

I Joumal of architectural d technology published by Hoffmann Architects, specialists in exterior rehabilitation,

First lssue 1990 Volume B Number I

Waterproofing I A RoundtobteDr'scusslon

B"for" a building owner or manager John Hoffmann agreed; "There are no makes a major commitment to wateÊ pat answers to problems of waterproof ng, he must determine whyihe proofìng. Questions must be asked: Did original system failed, Any attempt at the original system fail because ofage? waterproofìng before the underlying materials? installation? or design?" He cause has been found and the proper said the job of fìnding the cause and solution developed could result in then developing a plan for solving the È o wasted time, money and effort, problem begins with a physical inspec- U ' c according to the architeqts who took tion of the structure. o The interior as E part in the roundtable. úo well as the exterior needs to be c inspected to help pinpointthe exact : "There p is no one formula and no off- source ofthe leaks, c o the-shelf solution for making a wet U _q building dry," Walter Damuck told the The problem could be almost any- e group. "Before you can properly where in the building, according to úo correct the problem, you must have Russell Sanders. On the roof the o all of the facts at hand." problem o could be the fashing around L roof penetrations, around mechanical systems or around drain areas, lt could Editor's Note: Four key orchitects ot be the way repairs were made on the Hoffmonn Architects, Nonh Hoven, roof over the years. lt could be due to Connecticut, John Hoffmonn, AlA, princi- age ofthe roofor sheer neglect. Þol;Theodore Bobbttt, AlA, Director of Rockefeller Center's building envelopes Architecturol Servlces; Russe// Sonders, "Weak links in the building are often are among the best constructed and AlA, Director of Technicol Servlces; ond found in the curtain wall and masonry, maintained in the world. The Center's Wolter Domuck AlA, Director of Buildrng particularly at intersections or joints comprehensive maintenance program /nvestrgotlons hove devoted much of where the roof joins the parapet," prevents most waterproofing problems their coreers to rehobilitoting commerciol, Theodore before they occur. Babbitt told the group. industrial, retqil, hotel ond theoter buildings. Over the yeors, one of their greotest Explained Mr. Babbitt, "We try to chol/enges hos been to tcke leoky build- discover which materials within the ings ond moke them dry. Recently, the waterproof ng system are most orchitects porticipoted in o roundtoble vulnerable to failure. Nothing lasts dlscussion on how to provide o long-term forever, and if materials break down solution for the domp or wet building, they are a source of entry for water," The orticle which begins on this poge wrll prove informotive to buìlding owners, Mr, Damuck pointed out, "ln a brick monogers ond others who moy be foced building, mortar joints, the 'glue' that now or ìn the future with the economic holds the building together, often leak, nightmore of o wet building, ln one square foot of brick wall there

are l3 lineal feet of mortar-brick I lf the job was designed properly, was interfacing. lf each brickto mortar joint it aclually constructed accordìng to developed a hair-line crack of only the conlruction documents?

I l64th of an inch, that would result in the equivalent of a slot I 14 inch by "We look at how the job shouid have eight inches, and that is enough to let a been done and then evoluote if it was lot of water into the structure." in fact done that way " said Ylr. Hoff- mann, "When we discover that the job The roundtable agreed that brick and was not done the way it should be, we mortar joints must be carefully often have our answer as to why the inspected for problems because there waterproofìng system failed. By the are so many potential problems with time we are called to a job, the owner this area of a building is usually putting out buckets to catch I the water, lf the job was not done right ln this context, John Hoffmann men- the f rst time, he is usually very willing tioned that when a matedal that is no to listen to how it should be done this longer sold on the market is time around," discovered within the sylem it must be checked very carefully, Unfortunately, noted Mr Babbitt, by John J. Hoffmann, AIA the time the client does call us with a Studying Original Plans leaky building, chances are water has building complex is the mix of matedals Besides pinpointing the exact locations been infìltrating into the building long used. On older buildings, problems of leaks, it is also crucial to study the before it was noticed. This usually often result from age or neglect, ln original plans and specifìcations of the means that the building has been some instances, something has been structure: damaged by the water before the done to the building over the years to owner even realized ìt was leaking. alter the origi nal waterproofìng system. f What type of waterproofìng system ln the newer buildings and buildings was used? lnvestigating a Complex Building with leakage problems keep getting I Are there components within that Sometimes buildings are very complex newer and newer we fìnd poor system that may be incompa|ble? and it is diffìcult to determine exactly design, poor construstion, poor mat- I Are there questionable design where the waterprooîng system has erials or all three at once. Building details within the system? failed. Says Mr. Babbitl-, 'What makes a owners cannot believe how quickly a roof needs to be replaced, One of our clients who needed a new roof on his building commented that the roof on his house was 25 years old and in good shape,"

lYr. Babbitt went on to say, and the others at the roundtable agreed, that "there seems to be a lack of knowl- edge among architects regarding the use of materials I fìnd it surprising when I talkto people how little they really know about the matedals that go into buildings, Also, what contractors do to a structure can cause tremendous harm, I spoke with one person lt recently who uses roofìng cement con- Walter E. Damuck, AIA taining asbelos when he repairs a roof

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"That roofing felt is all lberglass, but rental area is measured from the inside water leakage problem. The fìrst prob- when it is replaced someone will take of that glass. The window fr¿mes were lem that was discovered was a struc- a core through an area and flnd the stuck out an inch-and-a-half beyond the tural steel problem. So a structural steel asbestos. Then it will become an outside face of the building to maxi- contractor was called in to repair it. As asbestos removal project as well as a mize the rental space, This is a very that contractor went on, evefihing re-roofing job and costs will double, poor waterproofi ng detai1." became a structurol stee/ solution, If the triple or quadruple. This person told owners had consulted a masonry con- me that half people the in his company Hoffmann Architects deals with other tractor, evefihing pnobably would use asbestos for repairs and half do types of water problems in new build- have involved amosonry solution. lf not." ings as well, accordingto lYr, Damuck. they had called in a carpentry contrac- "ln one new building it was 'raining' tor, I am convinced evefihing would Clean Design, Poor Waterproofìng inside, but it was not raining outside. have required a corÞentry solution." 14r. Babbi|_ told the roundtable that on The rain started in the morning on the some newer projects the problem lies east wall, f4id morning, it rained inside Working with Specialists with the "ln design of the building: an on the south wall, ln the afternoon, it The roundtable felt it makes sense to attempt to make the design so clean, rained inside on the west wall, lt never brrng in a specialist from the start to the design professionals do not want rained on the north wall. fìnd the root problem and to develop to see any little pieces of metal hanging an overall solution, Mr, Hoffmann 'What overthe top of the building They do had happened was that the explained: "We at Hoffmann Architects, not want to see the coping prolecting building was hermetically sealed on the have worked on many prolects that beyond the smooth plane of the outside with a lot of insulation on the suffered from severe water leakage building. They try to clean up the inside, There was a seal between the problems, Even though most problems design so much that there is no place outside and the inside wall. The water are unique, we have solved similar for flashing. The result is water leakage vapor on the inside condensed on the problems, many times. Second, many of into the building." inside of the outside wall and froze. As us come from a general background in the sun came around and heated up architecture so we know the systems the wall, water cascaded down on the overall. We are not looking at some- inside of the windows and the walls thing as a roof ng consultant; many onto the foors." times that problem with the roof might be caused by something else that Mr. Babbitt recalled a two-year old needs to be addressed And being building on Long lsland with water leak- architects, we can appreciate the aes- age problems, "We looked at the roof- thetics of it, We will not put corrugated ing detail and found three defects in aluminum siding on the side of a para- that one detail, Nobody really pays pet to cover up the brick work because attention to the roof At Hoffmann that is the cheapest way to go. We will Architects, we complete more detailing look for an aesthetic solution. We also for re-roofìng a small commercral build- understand that working on new building than many architects do for a brand ings and working on existing buildings new offìce building.' are very different. Exiting buildings must continue to operate with the The Structural Sreel Solution leasl Russell M. Sanders, AIA disruption possible to building One reason building owners and man- occupants." ager s have diffÌculty getting to the root Mr. Damuck also noted that on newer cause of a water leakage problem The roundtable was questioned as to buildings, problems could develop immediately is that they will call in a why calling in a qualifìed consultant is because of the way the windows are specifìc contractor who will impose a not the f rst step for many owners or designed, He spoke about a building solution specifìc to his trade. Mr. Hoff- managers. ltlr. Hoffmann answered: he looked at recently: "Sixty percent "At of mann explains: a major ofüce build- "An owner's fìrst thought is that a the outside wall was glass and the gross ing in New York City, there was a consultant just adds to the cosl On the

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client. These design fìrms spend time take the scaffolding down and re-erect making sure the conference room it on the other side of the bridge. To work, that the atrium meets code. But wash the glass on the bddge, they must for actual detail work-the way things go up to another level and erecl a scaÊ go together in the building the only fold on the bridge. This is a substantial thing they are concerned about is on-going maintenance expense. Anoth- aPPearance," er item that often gets overlooked is how watertight the building is. The Mr, Hoffmann suggested that many maintenance staffgets tied into that as architects, hired strictly for their design well." skills, do not know a great deal about how systems work together. He told Building Substructures the roundtable: ' lf it were up to the lYr. Damuck said to the roundtable: people maintaining the buildings they "We have talked about the top of the would probably never hire some of building but we have not said a word these design firms again because the about waterproofìng problems at the maintenance people have to handle the feet of the building..the area of the Theodore F. Babbitt, AIA problems that result from some of building that is underground, lt is a spe- these designs. Generally, however, they cial study. lt is a special study because the newer building, flrst he goes back have no input into corporate decisions. no one wants to do the obvious which to the original archilecls or engineers is to dig a trench around the building and when he has exhausted that, he "What usually happens is that the and waterproof the outside of it," brings in a contractor. When that does chairman of one company calls up the "The not work, then he decides to bring in chairman of another company who lust Said Mr. Hoffmann: basement of someone who does this type of work had a new headquarters built and asks a building is one of those areas where for a living," how the building is working out, The one seldom gets a second chance to other chairman says 'great', he loves it, do a good waterproofìng job The thing Mr. Damuck interjected: "When an his offìce is comfortable, Yet if the is this type of wort is not diffìcult to do owner sees water coming in, hìs f rst maintenance people in the building right the flrst time around, but in urban reaction is to call a roofer. The roofer were asked aboutthe building they areas it is tremendously expensive to goes up on the roof with a big bucket might tell a different story, do a second time. There is a tremen- of 'stuff. Wherever he thinks there is a dous cost and tremendous inconve- problem he smears it on, He often nience to the public involved because smears it on weep holes that are sup- llThrrc sidewalks must be ripped up and the posed to drain water from the parapet ore no Þot building must be excavated down three walls which create problems later," onswers to þroblems of or four stories," lYr. Hoffmann continued: "ln many of woterÞroofing.)l lYr. Damuck responded somewhat these situations, particularly new build- tongue-in-cheek "By the time you get ings, the architect was hired for his municipal permits to do this type of design abilrties. There are architects "ln one new building I know of the worl<, the people who owned the who say they will take care of the interior courtyard is surrounded by building have died," design and someone else will take care glass and there are bridges at various of the documents, Their responsibility levels going from one side to the other, "Waterproofìng basements remi nds is to make sure that the building is lf the windows in the courtyard get me of taking ceramics in college," said attraclive, the spaces work together, dirty there is no efficient way to clean lYr, Hoffmann, "l would spend hours and space is effìciently used based on them. The maintenance staff has to put sanding a piece of ceramic that did not the budget Those are all extremely together rolling scaffolding, rolling sta- come out lust right But two days important and if they do not work then tions to clean the glass, But every 20 before, that matedal was soft clay and the building does not work for the feet there is a break and they must it could have been easily changed."

4 Volume B Number I

ln concluding the roundtable, the four architects The Facility Manager's Bool

Nf Roofng & Woterþroofing Monuol,3rd Ed. (g I | 8.00) B"fo." attempting to make a wet !A NRCAWoterþroofing Monuol,3rd Ed, (included in above rtem; g27.OO) (item building dry, the most critical slep is to 2t4) determine why the system failed. A Rooftng Moteriols Guide (subscription for 2 issues per year, 995.00; ltem 40 l) minimum of three steps should be By mail: Roofing Resource Center, NRCA, p.O Box 3 129, Oak par{, lL 603b3 Handling charge: taken to determine the cause of failure. 92.00 B. Compilations of Product Literature l. lnspect the inside ofthe structure L Woterproofing ond Dompþroofing Moteriols ond Systems. Concrete and pinpoint the exact location of inte- Sourcebook, October 1989. $ 10.00 including postage. rior leakage, On walls and floors this is lnquiries: (800) 323-3550 or (3 I 2) 543-OB7O By mail: The Aberdeen Croup, 426 a relatively easy task, On ceilings, the South Westgate, Addison, lL 60 lO I By FAX: (3 l2) 543-3 I l2 job is more diffìcult, For example, stains on suspended ceilings will not always 2' Mosonry Products for Historic Buirdings. rggg g7.oo; check payabre to: Center be immediately underthe leakage for Architectu ral Conservation. By mail: Center for Architectural Conservation, College point. Water may be flowing along a of Architecture, Georgia lnlitute of Technology, Atlanta, GA 30332 beam or a constnrction joint for some lnquiries: (404) 89 4-339 0. distance before it drips off Remember 3. See also section 07 i 00 in SWEEIS Cotolog Files, also that pinpointing General Building and the location of the Renovation. interior leakage does not guarantee General that the entry point through the water- C. Reading proofing system is directly above, L The Applicotor, newsletter, Water may be entering the water- By mail: sealant, waterproofers, and Restoration Institute, 3 lo I Broadway, suite proofing and traveling laterally under 300, Kansas City, MO 64 | I l. By phone: (8 | 6) 56 | -8230 the waterproofng. 2. ASTM (for ordering information see part A above.) Molsyre Migrotion in Buildings. Edited by 2. Study the original plans and specifì- Lieff & Trechsel, 29 I pages, l9g2 (STp 779).939.00. Order Numben PC l: 04-779OOO-|O cations. Determine what type of water- NRCA (for ordering proofìng system was used in the I information see part A above,) ProcticolGuidelines to Control Woter Domoge, g4.OO. ltem original construction. Are there compo- 222. "Waterproofìng nents which may be incompatible? Are 4, and the Design professional,, by Brent Ander son. Ihe Construction Specifier, March | 986, pages there any questionable design details 84-97. For article copies, write to: construction specifìcations lnstitute, 60 I lyadison which may have interfered with good Street, Alexand ria, Y A 223 I 4- I 79 I waterproofìng practice? Could there be lnquiries: (703) 684-0300, Price per copy g4,OO, Minimum order g 10.00. r

cont¡nued poge on I Compiled by Alan Eddy, Technical Libr¿rian

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ln *ut"rp.oofìng, there are pros and and disadvantages ofeach system. cons to applying the waterproofìng The same waterproof ng applications system on the posltlve side (the slde of Positive Side vs. which might be employed with oÞÞlted hydrostotic pressure) and pros relative ease and cost effectiveness and cons to applying it on the negotive Negative Side during new construction often slde (the slde opposite to oÞÞlied become unfeasible or cost prohibitive hydrostotic pressure), What follows Waterproofing during rehabilitation of an existing is a discussion of the advantages struclure,

Negative Side Waterproofing Positive Side Waterproofing

Negative side waterproofìng involves placement of a waterproof Positive side waterproofìng involves placement of a waterproof barrier on the side opposlte to oÞÞl¡ed hydrostot¡c pressure, barrier on the slde ofoþplied hydrostotic Þressure. Typical negative side interior applications are for foundations, Typical positive side applications include waterproofìng the pits, tunnels, shafts and slab toppings below grade. Negative side exterior of accessible below-grade struclures and above-ground applications are also effeclive on structures where the foundation roofs, piazas and deck. Positive side applications on the interior is placed directly againstthe rock, thereby making a positive side, include planters, fountains, dams and other waterholding structures. exterior application impossible, Negative side applications on the Some of the positive side applications are left exposed to a exterior include sealing waterholding structures from the outside, harsh environment. These exposed applications, especially above- Exposed applications from the negative side may require ground applications, also may requìre special properties such as additional material properties such as traffjc, abrasion, erosion and trafrìc, abrasion, erosion, weathering, chemical and ultraviolet puncture resistance. Since many negative side applications are resistance, In addition, exposed applications may require water- interior and below grade where they are left exposed, they are proofìng with a specifìc color and finish, often specifìed with various colors and fìnishes, lYany types of positive side waterproofìngs, such as bentonite, Only a few types of special, rigid membranes and other water- cannot be used in those areas subjecled to moving or running proofìngs are effective on the negative side, such as cementitious water, or earth settlement which may cause the waterproofìng to membranes and metallic oxide waterproofìngs. Since these wash away, erode, shift, settle, tear or come apart at seams, ln materials are rigid, close atlention must be given to joints and additìon, clay waterproolng is not effective in areas where the struclural stability and rigidity, water contains certain chemicals, Certain elastomeric membranes signifìcantly change properties when exposed to extreme temper- Advantages of Waterproofing from the Negative Side atures, ultraviolet, weathering and normal aging. Cementitious I Concrete remains moist cured, membranes require special treatment and consideration in areas I Elìmination of dryìng shrinkage due to continuous moìst curing. subject to movement due to their rigid nature. moist I Continued increase in concrete strength due to curing, Advantages of Waterproofing from the Positive Side I No waterproof ng excavation cost incurred for interior application, I Protection from chemical attack if water contains corrosrve r Early backfìlling in new construction and no possible damage substances, from backfìlling. I Protection from freeze/thaw damage for above grade structures. I Easy location and repair of damage for exposed barrier I Utilization of both rigid and elastomeric barrier systems, applications, Disadvantages of Waterproofing from the Positive Side Disadvantages of Waterproofìng from the Negative Side I Water is blocked from entering the concrete causing it to dry I No protection of substrate iíwater contains corrosive chemicals. out, resulting in drying shrinkage and cracking. I No proteclion from freeze/thaw damage for above grade I Lack ofcontinuous moist curing stops further concrete strength concrete, development, r Limited to the use of rigid barrier systems. I Excavation costs incurred to,/make the exterior surface accessible for barrier application on below grade structures may Adapted from materials coudesy of U S. Woterproofing be additional, I For below grade applications, the barrier may be inaccessible for Waterproofìng repairs after backfìlling or placement of topping slabs, I Membrane

Water Negative side. Water Water Positive side. Water is enters concrete. blocked from entering concrete.

Waterproolng lYembrane

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REPRESENTATIVE PR otEcTs

Corporate Headquarters Buildings

Hoffmann Architecls specializes in Union Carbide Corporation the rehabilitation of the exteriors of Danbury, Connecticut existing facilities, CBS lnc. Its professional architects and engi- New York, New York neers diagnose the causes and design the solutions for deterioration Shawmut Bank, N.A. and water infiltration problems Boston, I'4 assachusetts within roofs, facades, windows and structural systems. Associated Press New York, New York The fìrm conducts Building Condition Surveys, prepares Con- Chesebrough-Pond's lnc. struction Documents and provides Greenwich, Connecticut Construction Contract Adminis- Southern New England Telephone Company Headquarters Building, tration seryices for waterproof ng Exxon Corporation New Haven, Connecticut and rehabi litating exteriors, New York, New York Bank of New England Corporation Hoffmann Architects has provided The Gillette Company Boston, Massachusetts services for some of America's Boston, lY assach usetts largest corporations, including work GE Capital Corporation on the following Corporate l.lead- Pennwalt Corporation Stamford, Connecticut quarters Buildings: Phi ladelphia, Pennsylvania Heublein lnc. General Electric Company Simon & Schuster lnc. Farmington, Connecticut Fairfìeld, Connecticut New York, New York National Broadcasting Company lnc. GE Building, formerly RCA Building New York, New York

Southern New England Telephone Company New Haven, Connecticut

American Cyanamid Company Wayne, New Jersey

Warner Communications, lnc. New York, New York

Unilever United States lnc. The Lever House Union Carbide Corporation Headquarters Building, Danbury, Connecticut New York, New York r

7 Hoffmann Architects / fournal

-7 +' o 9p Tips ;D Pã ) Waterproofing { if d+ continued from poge 5 St¿ff News P J4 U ol Z læ dP problems associated with expansion C) 9;^o o< joints or the lack of expansion joints? Z oo)< Ø U C.cñl P-f"rrion"l Accomp I ish mentsr Are drains properly located? A study Êo U of plans and specifìcations is unlikely to U O ;Ð Õ John J. Hoffmann, AIA was elected answerthe question of what caused m r_t-È President of the Building Owners and failure, but it may be valuable in estab- o o lYanagers Association of Southern lishing probable causes. lt will help .D P Conneclicut. guide the actions in the fìnal and most ôm --.1 revealing step, o Russell M. Sanders, AlA, Theodore F. Z ,ú Babbitq AlA, Amy C. Kilburn, AIA and 3. Excavation and inspection must be m Oa John J. Hoffmann, AIA serye as inslruc- done in order to reliably understand m --.1 tors in BOMA Southern Connecticut's the nature of the problem. Results m U newly developed RPA Program. from Steps I and 2 will help in developing a plan for excavation or removal Theodore F. Babbitt, AIA continues of overburden and inspection. Care to serve on the lndustry Pr¿clices Com- should be take during excavation or mittee of the Connecticut Building removal of overburden. Under the Congress. best of conditions, it may be diffìcult to be absolutely sure of the cause. lf the Brian W. Schafer continues his involve- point of water entry is not found, fur- ment with BOMA New York, He ther excavating will be needed. r seryes on the l'4embership and Seminar Committees and was recently appoint- Courtesy of W.R Groce ond Compony ed Vice Chairman of the BOMA NY Professional Members Committee.

Hoffmann Architects won /OURNAL /OURNAL is a publication of Hoffmann Honorable Mention in the 1989 Soci- Architects, specialists in investigative ety for Marketing Professional Services and rehabilitative architecture/ engi- Award Program. Ann M. Prokop, edi- neering, including the analysis and solution of problems within roofs, tor oftheJOURNAI accepted the exiedor walls, glazing and structural award atthe SMPS National Conven- systems of existing buildings, plazas tion in Boston. and parking garages,

New Staff Please send news, technical information, address changes or requests for free subscriptions to Ann Prokop, Hoffmann Architects is pleased to Editor, Hoffmann Architectsf OURNAL introduce the following new staff mem- at 432 Washington Avenue, North bers: John D. Kennedy, Project Mana- Haven, Connecticut 06473, ger; Stuart H. Radin, PE, Project Enginee¡ Darrick M. Potter, Drafterl For answers to specifìc questions or for information on the services we Prolect Representative; P. Janusz offer, please call Brian Schafer at Sawko, Drafter/Project Representative; (203) 73e-6660. M. Christine Burr, Bookkeeper; Alan P. Eddy, Technical Librarian. r