Architects, General Contractors & Pest Control Technicians Have Little Understanding of Waterproofing, Why Does Berkeley Want Them to Inspect Decks Then?

On June 24th I wrote a detailed letter to the City of Berkeley's Building Department, City Manager and City Solicitor regarding their memorandum of proposed changes to the Cities Building Codes.

They want to implement various changes related to the construction of and methods of waterproofing balconies, along with requiring inspections of decks and balconies on apartment complexes and condominiums, While their proposed changes are well intentioned, some of them are a little crazy in my opinion.

My biggest objection is having Architects, General Contractors and Pest Control Technicians inspecting decks...why do I say that?

Read my letter and leave a comment telling me what you think!

June 24, 2015

City of Berkeley

Mr. Eric Angstadt, Christine Daniel, Zach Cowan

Building & Safety Department

2120 Milvia Street

Berkeley CA 94704

Dear Mr. Angstadt, Ms Daniel and Mr Cowan,

Let me first say that I am deeply sorry and anguished over the tragedy that occurred last week with the deaths and injuries to thirteen people. I cannot fathom the sorrow that the bereaved parents and families must be experiencing.

My background includes six years as an estimator/sales person for several large deck waterproofing companies doing business in the San Diego/LA/Orange County/Ventura/San Luis Obispo areas, as well as being a CSLB licensed (currently inactive) waterproofing contractor for seven years. I am now a consultant and perform deck inspections for real estate transactions and for HOA's. I have sold and installed hundreds of thousands of square feet of deck systems in my career.

I have been one of the experts used by several media sources for comments and opinions on the causes of the deck failure. As owner of DeckExpert.com I promote the use of Pedestrian Traffic Coatings at our website of the same name for use on balconies, stairs, roof decks and walkways. Pedestrian Traffic Coatings are walkable waterproof membranes typically used on decks, stairs and balconies covered with plywood decking and these are also listed and evaluated as roof assemblies for low slope roofs. These membranes are listed in ICC-ES' website under Division Seven Thermal and Moisture protection under 07 18 13.

I would like to take a few moments of your time to lay out my recommendations that the City of Berkeley should consider implementing to avoid another tragedy in the future. I understand that there are several recommendations already in the works, and I would hope you will consider incorporating my recommendations as well.

As you know already, the deck that failed appeared to have a Grace 3000 bituthene membrane as it's waterproofing, covered with a topping slab of concrete. Basically this is the same as a plaza deck, found over below grade parking structures with the living units built using wood framed construction. These plaza type decks must be carefully assembled as once covered with a topping slab, the waterproofing is impossible to inspect or repair without removal of the topping slab. Plaza decks must have a subsurface drain system in place to deal with water that is bound to get under the topping slab.

Plaza decks in my opinion and experience have had many problems with their assemblies in the past, due to the technical skill necessary and the usual lack of skilled labor who understands how to assemble them. I believe that these types of assemblies should be banned from use on top of wood framed and plywood covered decks.

1. In lieu of plaza deck assemblies, I would instead propose that the City of Berkeley consider implementing a requirement that only pedestrian traffic coatings be used on plywood covered decks. The main reason for this is that pedestrian traffic coatings are “an all in one” solution to waterproofing these decks while providing a walkable surface at the same time. They can be easily inspected and are relatively easy to repair if damaged. Most Division Seven Pedestrian Traffic Coatings are also Class A roof rated systems (ASTM E-108) and many are also rated as One Hour assemblies (ASTM E-119), therefore meeting the Cities fire resistant requirements. Many of these systems can be finished in any number of ways with texture and pigmented sealer as well as stained/stamped etc to look like tile, stone, wood etc. There are several different system types available, leaving architects and specifiers choices among concrete based coatings, liquid applied coating, slip sheet systems and sheet goods. Concrete and many of these coatings can also be used to correct deficient slope conditions, so achieving a 1/4” slope per foot is very easy to do on flat decks that were not framed with slope in them.
2. In regards to the Berkeley Building Code changes proposed, I concur with the recommendation to require Ventilation of weather exposed enclosed assemblies under Section 1203.6. Most of our manufacturer's already require this in their general requirements in their CSI specifications. I also concur with the inclusion of access panels on the underside for inspection of the framing.
3. In regards to adding Section 1404.13 Projections exposed to weather, after consideration, I concur with using pressure treated wood or steel for framing the deck. I do believe that properly waterproofed, conventional douglas fir framing is perfectly suitable for the framing, however, rot resistant materials will certainly perform better if exposed to water over a longer period of time.
4. Under Section 2304.11.4.2 Wood structural members, I propose that the City eliminate the use of moisture permeable floors or roofs such as concrete or masonry slabs. My reasoning is that these types of assemblies trap water in them and as they are typically part of a plaza type deck system, are not conducive to using them on balconies covered in plywood anyway.
5. Regarding adding Section 601.4 Structural Maintenance; I concur with requiring inspections. I have several changes to propose; these being requiring inspections every two years instead of the proposed five year interval. In my experience as a waterproofing contractor and consultant, five years is to long between inspections. A lot of serious damage can occur in a short time. Manufacturer's of Pedestrian Traffic Coatings require as part of their warranty that their systems be inspected yearly. Regarding who should inspect the decks-waterproofing is a specialty trade. In my work as an educator, I usually have a room full of people where 90% or more are general contractors. General contractors are just that, generalists. I've found in my experience that most do not understand waterproofing in general and decks in particular. While structural pest control licensees know the signs of dry-rot, wood destroying organism infestations etc, they do not understand waterproofing either. Engineers and architects are generally familiar with waterproofing concepts and can certainly recognize inherent defects and issues with contiguous building materials and would be suitable candidates to perform inspections. I believe the best candidates to perform deck waterproofing inspections are waterproofing consultants. As a group, we are very familiar with installing and maintaining waterproofed decks and balconies. It may sound self-serving and I appreciate anyone thinking that it is, however, as an example, I've spent nearly 14 years as an estimator and owner and applicator of a firm specializing in waterproof deck installations. I've found that many of my peers were applicators and as we “age” out of being able to work on our hands and knees we seem to transition into consulting and inspecting. The Roof Consultants Institute (RCI) and Sealant Waterproofing Roofing Institute (SWRI) are two organizations that are focused on roofs, decks and waterproofing systems and are probably best qualified to do such inspections. We have familiarity with general building requirements and understand the importance of contiguous building materials needing to be weather resistant as well.
6. I would suggest that the City add the following requirements for deck waterproofing; these being that building inspectors begin inspecting the waterproofing of the decks as it's being installed, including inspecting the flashing system and substrate prior to covering with a membrane. Most importantly, inspectors should verify that the deck is sloped or tag the deck so that it will be sloped and they can check the slope before signing off and allowing finish coats to be installed. Once the membrane is installed, but before it is decoratively finished, it be inspected again. As part of the requirements, the City should allow only ICC-ES pedestrian traffic coatings with Class A ratings minimum and One Hour where already required. The ICC-ES report should be made part of the submittal for building permit approvals.
7. Regarding substrate-the use of Oriented Strand Board (OSB) for pedestrian traffic coatings is not accepted by ICC-ES nor any manufacturer. All fire testing is performed using plywood only. OSB, in my experience, despite the claims by manufacturer's that it's better at water resistance, is a sponge. I've seen OSB expand and it doesn't return to it's original dimensions. Therefore, OSB should be banned for use on decks and plywood be the only acceptable substrate allowed. I would caution against requiring pressure treated plywood, mechanical fasteners used on some systems may not be compatible and liquid applied coatings may have issues as well with compatibility.
8. Regarding railings-steel/aluminum railings that mount onto the deck should be banned. In my experience I've found that it is impossible to guarantee a waterproof deck won't leak when railings penetrate the waterproofing. Only metal railings that mount to the fascia should be allowed. Wood 4x4 posts penetrating through the plywood and bolted to the deck framing can be flashed and waterproofed. The key in waterproofing these wood posts is that they MUST be wrapped with bituthene/Tyvek/building paper and then either boxed in for a final finish or a post sleeve, typically made of plastic/synthetic materials is slipped over and finished on top with a decorative “hip roof” style cap to shed water.

As a general note, it is contained within the CBC 1998 code 1402.2 that openings in exterior walls are required to be flashed in such a manner as to make the opening weatherproof. For waterproofing purposes on decks, metal flashings, be they galvanized steel, copper or stainless steel, are meant for the purpose of terminating our coatings to. All deck waterproofing systems must be run up the vertical leg of the flashing so that contiguous building materials are installed down over the flashing, forming a weather resistant barrier. Counter-flashings, be they Z bar or weep screed for stucco provide the mechanism for water to be shed off and away from the buildings interior.

Furthermore, as a general note, building inspectors and the building department must ensure that proper weather resistant barriers meant to waterproof the decks, the building and the foundation are specified and installed properly. These systems are just as, if not more important to long term comfort, use and enjoyment of the building than framing, mechanical and electrical systems. Inspectors should be required to closely inspect all weather resistant barriers, including siding, windows, doors, foundation waterproofing and the decks and roofs to ensure they meet or exceed code requirements.

I sincerely appreciate your concern in wanting to strengthen and improve building codes and requirements for the safety and security of occupants. I hope these recommendations will be considered and implemented. I am willing and able to appear in front of any panel, council meeting or with the building departments staff to discuss these recommendations. Please let me know if you would like me to appear to testify/discuss.

Sincerely,

William Leys  

San Francisco Chronicle & Los Angeles Times Utilize Our Expertise in Understanding the Berkeley Deck Failure

No one wants to see a headline like this, with 6 dead & 7 others seriously injured.
Both the LA Times & San Francisco Chronicle have used us as a source
on their investigative articles. 

DeckExpert.com provides consumers with information, videos articles and more for buyers to make informed decisions on deck systems. We also provide articles to major trade magazines for the HOA, Construction and Architectural industries. 

Now we are pleased to say our expertise is helping reporters understand the problems that caused the recent Berkeley deck tragedy where the a waterproofed balcony, only 7 years old, failed catastrophically and thirteen people plunged to the ground, killing six and seriously injuring the other seven survivors.

Both the the Los Angeles Times and the San Francisco Chronicle have interviewed us for their investigative articles into the how and why this tragedy occurred.

From the Chronicle  article-“This is all a vicious combination,” Leys said. “The penetrations, the drainage and lack of ventilation underneath — they all combined in a catastrophic failure.”
Read the SF Chronicle article by award winning reporter Jaxon Van Derberken here  http://www.sfgate.com/bayarea/article/Blueprints-show-Berkeley-balcony-was-designed-for-6336566.php

From the LA Times article- "Balconies just don't fall off a building like what we saw without having a few years of deterioration," said Bill Leys, a former deck waterproofing contractor who now inspects decks in San Luis Obispo for his company, DeckExpert.com.

Read the LA Times articles here. http://www.latimes.com/local/california/la-me-berkeley-balcony-collapse-20150623-story.html

Deadly Berkeley Balcony Collapse - Poor Design, Poor Workmanship in Installation

The six people that died and seven who were seriously injured in the balcony collapse on an apartment building on Kittridge St in Berkeley CA never should have died or been injured. That's my opinion, based on the information and documents I've received and photograph's I've reviewed.

Eventually a jury or a mediator will award the dead and injured money to compensate them. Who will pay and how much they will pay will be the only question.

Broken off joists from dryrot due to water intrusion.
Decks must be pre-sloped, then waterproofed. 

From what my review and discussions with other experts have come up with, the wood cantilevered deck was framed out flat, despite the plans calling for a 2% slope on it. After being built, it was waterproofed using Grace 3000 bithuthene membrane, a peel and stick waterproofing sheet good.

Grace 3000 waterproofing system on horizontal surfaces
requires the use of a sub-surface drainage membrane under the concrete
overburden to allow water to escape unimpeded. 

Waterproofing detail for deck shows Grace 3000 bituthene membrane
but the drawing FAILS to include Grace Hydroduct 660 Drainage Membrane.
We presume water WILL get under concrete overburden and will need a way
 to drain sub-surface water out

After being waterproofed, it appears that sloping materials in the form of concrete backer board type materials were placed on top, then screwed down through the waterproofing membrane. Grace advertises that their membrane is "self healing" but also advises that any penetrations be patched. Near impossible to do in this type of situation. But someone probably thought hey it's self sealing so no problem screwing through it.

Apparently no further waterproofing over the sloped materials was done.

Then a concrete deck was poured over this assembly. Water will leak through concrete. It's permeable unless it's waterproofed. Stucco was applied as the finish under the balcony. One design flaw with the stucco was that no vents were installed on the underside of the deck.

Clearly there are no vent strips on the underside of the stucco covered deck. 

My theory is that water got through the concrete and in at the door area. The fasteners used to screw the concrete board down allowed water to penetrate to the waterproofing membrane. As screws rusted, they provided a channel for water to penetrate into the deck substrate and framing. Now with the wood wet, dryrot could begin.

This pic clearly shows the joists of the deck in a rotted condition.

Now I want to be clear, the design of the waterproofing appears to have been a problem too. I've reviewed details of the waterproofing assembly and the architect appears to have left out on critical piece of the system assembly-subsurface drainage. 

The Grace 3000, like nearly every Grace waterproofing product, requires a drain board assembly to be placed on top of the waterproofing membrane over a pre-sloped substrate. Without the ability to drain water out, concrete will hold the water against the waterproofing membrane, allowing it to sit, especially on a flat deck. The Grace system, if properly designed and assembled, should have worked for years and years without issue. 

So a flat deck, with waterproofing on it without slope, allows water to sit on it under the concrete overburden. Theoretically this deck as it began to deteriorate. My question then becomes, were the decks at the property ever inspected by the management company or a building evaluation specialist? My reason for asking is I would think that some signs of distress may have been present and noticeable to an expert. I say this because experts inspected the other decks on this property and determined several were dangerous and were red-tagged. Therefore it's reasonable to assume this deck, had it been inspected, could have been found to be dangerous before this tragedy happened. 

The lawyers will figure it out, the insurance company will pay out and we as a industry in building and protecting occupants, must become better at our trades, in both design and assembly. Someone has to own their work and take pride in it and do it right. 

We can't afford cheap construction.  

Bill Leys Ten Commandments of Deck Waterproofing (for Builders)

Having been i n the waterproofing business now for over 5 years, I see the same errors made over and over.
In order to assist builders and consumers,I have developed what I call the Ten Commandments of Deck Building for Waterproofing.
Easy to follow, easy to understand, set these basic principles in stone and don't waver from them when working with your clients, you'll help protect yourself, your deck contractor and most importantly, your client.

1) Thou shall build thy deck with framing suitable to sustain the maximum load that 12)will be placed upon the deck.
2) Thou shall rip thy framing to provide slope of ¼” per foot.
3)Thou shall only use exterior grade plywood substrate. (5/8” minimum, ¾” preferred, blocked and glued) (Thou shalt not covet thy neighbors OSB sheathing.)
4)Thou shall use screws or ring shank nails only with glue and blocking.
5)Thou shall gap thy plywood to allow for expansion/contraction.
6)Thou shall raise door thresholds a minimum of ¾” above the highest point of the deck.
7) Thou shall not penetrate the deck with railings or bases if possible.
8) Thou shall build thy walls straight and true so that flashing can be installed tight against the wall.98) Thou shall flash the door(s) to the deck with door pans tied into the L flashing.
9) Thou shall provide a stucco stop on the outside edge for drip flashing to terminate over the siding.
10)Thou shall install Quickflash Products to all exterior HVAC, electric, gas and plumbing penetrations on contiguous building materials above the deck.

FREE EXTRA BONUS COMMANDMENTS!
11) Thou shall not run downspouts onto decks from roofs above and expect scuppers or drains to drain off all the extra water.
12) Thou shall install all building materials in a weatherboard fashion to ensure water is properly channeled away from the building’s interior.
13) Thou shall not caulk to the materials of other trades to terminate waterproof deck coatings as a substitute for flashing, as flashing is the only industry accepted method to waterproof all deck terminations including doors, deck to wall, handrail posts; door thresholds, etc.