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Be in Compliance: New Decking Requirements
by Tim Carrico
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You recently received your periodic notice from the San Francisco’s Housing Inspection Division that they want to perform a routine inspection of your apartment building. That sounded fine; you’ve been through it before and know the drill. But what’s this new additional requirement? They want you to hire a contractor or architect to inspect and certify the condition of your back stairs and other “exterior attachments”? Where did that come from?
Section 604 of the San Francisco Housing Code was created about five years ago, after a couple of disastrous failures of decks and railings attached to San Francisco residential buildings. These unfortunate accidents made it clear that closer attention needed to be paid to detecting structural failure in building components that are exposed to the weather.
Most wood used in construction is susceptible to a fungus infection, commonly called dry rot, which is actually triggered by excessive moisture, not dryness. This fungus basically eats the fibers of the wood and turns what is left into flimsy mush. Moisture also causes metal fasteners, such as nails and bolts, to rust. Deteriorated wood and fasteners plus the weight of people can equal collapse.
In trying to figure out how to adequately inspect the many thousands of stairs, decks, fire escapes and landings in San Francisco, the Department of Building Inspection realized it just didn’t have the resources necessary to perform the many time-consuming inspections that would be required each year to keep up with the problem. Therefore, an ordinance was drafted to require third-party inspections by qualified persons: licensed architects, engineers and contractors.
There is a simple one-page affidavit the inspector has to fill out and sign, which states that, as of the date of the inspection, any of the listed structures existing at the property are in “general safe condition, adequate working order, and free from deterioration, decay, or improper alteration that could cause a safety hazard.”
Apparently, some professionals have been reluctant to perform the inspections for liability reasons. But David Gogna, senior housing inspector, said the department is not interested in holding people liable for future problems that may occur. He said city inspectors are well aware that problems like dry rot can appear to be minor or non-existent at one point in time, and a year or so later, significant damage can appear. “Sound at the time of inspection” is the standard, according to Gogna.
Due to the nature of weathering and dry rot problems—this type of deterioration is a constant reality in our climate—owners should expect that the initial results of an inspection may reveal some degree of work that might be required before the third-party inspector can sign off on the building.
Many people assume that the inspections required by this ordinance only apply to wooden structures, but the actual language of the ordinance goes beyond just wooden assemblies. It applies to, “All wood and metal decks, balconies, landings, exit corridors, stairway systems, guard rails, hand rails, fire escapes, or any parts thereof . . .” The phrase that seems to be missed often here is “fire escapes.” Under this ordinance, the inspector should verify that all fire escapes are adequately attached to the building and that the attachment means are not failing due to rusting of the bolts or failure of the wood holding the bolts.
Dealing with Delinquent Decks
The law requires periodic inspections, but what do you do if your building needs work to pass the inspection, either a little repair or a major replacement of a stair or deck system? There are two primary considerations. First, if it is necessary to replace a major component like a rear stair system, could a change in the design increase the value of the building? Most older San Francisco buildings have rear stairs, but they do not have decks. Is there a way to design decks into the system? Whether a building is intended for rental use or to be sold for owner occupancy as a single-family house, condominium or TIC, people will pay more to have a deck, whether they ever actually use it or not.
Another consideration is converting “winder” stairs to straight stairs. Many buildings here use winder-style stairs (narrow, pie-shaped steps) because they require less space. However, they can be difficult to walk on safely and are very difficult to build and maintain. Sometimes there is enough room to change the configuration to straight stairs. When building new stairs, they are supposed to comply with the current building code, which requires the treads to be 36 inches wide. In the past, I have been able to get the city to somewhat relax the code requirements when there wasn’t sufficient space to build the ideal, code-level system, if I could show that the new straight-stair design would still be far more safe and easy to navigate than new winder stairs.
The other important factor to consider, whether the work you need to do is a complete replacement or just a repair of the damaged sections of the existing structure, is that the materials and construction techniques and details will determine the service life of the work you have done. Dry rot in San Francisco has become a much greater problem in the last 25-30 years than it was in the past. The primary reason is that the wood that is available now is almost all from “second growth” forests, whereas virtually all of the older buildings in the city were built with “old growth” Douglas fir and redwood lumber. These trees were hundreds of years old and had time to build up the tight grain, tannins and other chemicals that made them rot resistant, in the case of redwood, and somewhat rot resistant in the case of Douglas fir.
Today, pressure-treated lumber, the imported hardwood Ipe and composite decking are the safest bets. Railing systems can be safely built from redwood since they are well exposed to the air and can dry out relatively quickly if they are designed correctly. Most of today’s pressure-treated lumber requires specially galvanized fasteners and brackets, so if you are talking to a contractor about this type of work and he or she isn’t familiar with this requirement, look into using someone else. All redwood lumber grades are not adequate for this type of work. The lumber should be at least “Construction Heart” grade—the dryer the better. The outer parts of the redwood tree have the newest wood, called sapwood, and in the case of redwood, this wood is usually white because it has not acquired any appreciable amount of the tannins that protect redwood. This lumber is much cheaper and usually sold “green” or still very wet with the natural moisture of the tree. This type of redwood can rot very quickly if it is sealed with paint or other coatings, or simply used in a method that doesn’t allow the natural moisture to escape. Even if you install it correctly, it will still probably rot, just not as quickly.
In addition to the types of materials used, the design or construction details can have a major effect on the life of an exterior structure. I won’t list details here, but the general idea is that the structure should shed water away from itself as much as possible and not trap moisture between wooden members, particularly against the ends of boards. End grain is like a wick and draws moisture into the wood, where it stays and nourishes the dry rot fungus. Mistakes particularly occur in the design of handrail and baluster systems.
DBI is compiling a database of properties that have submitted the third-party affidavits so that future notices can be sent out in a timely fashion. Inspector Gogna said it is not known at this time if owners will get advance notice that an affidavit is expiring, so you might want to find a way to calendar your expiration date yourself.
The opinions expressed in this article are those of the author, and do not necessarily reflect the viewpoint of the SFAA or the SF Apartment Magazine. Tim Carrico is a past president of SFAA, a former Rent Board Commissioner, and the owner of TCO, a San Francisco real-estate brokerage specializing in sales and consulting for property owners. He can be reached at 415-621-1600 or tim@tco-sf.com. Copyright © 2008 by Black Point Press. All rights reserved.