In 1977 I purchased my first home in San Francisco, a Queen Anne Victorian built one year after the 1906 earthquake and fire had devastated San Francisco. The front stairs for the home were original, and extended from a raised concrete landing to a small enclosed front porch just outside the original front door. Everything on the stairs above the concrete landing was solid wood…the stair stringers, the treads and the risers. And even though they were seventy years old the year I bought the home, they were actually in pretty good shape!
But as the Victorian era was ending in San Francisco, so was the era of building homes with exposed wooden front stairs. Terrazzo stairs became quite common, with both the treads and risers for these stairs being fabricated off-site, and then placed over wood framing or a concrete support. And although the Terrazzo material was solid and not prone to water intrusion, the joints where the treads and risers abutted the vertical framing often leaked after decades of service, with the water generally making its way into the basements of these old homes.
Although less common than Terrazzo, many old homes in San Francisco were built with brick front stair systems. These systems almost always involved a brick cover over a wood-framed or concrete substructure, and just like the Terrazzo stairs, once the bricks start leaking, the sub-structure becomes saturated with water.
The good news was that these systems which were wood-framed were almost always left as open framing, so the framing was allowed to dry out between rain storms. And if the supporting structure was solid concrete, there was no wood framing present to rot, even if the water intrusion was significant. But over the years, as real estate values continued to rise at extraordinary rates, the owners of these old homes in San Francisco started to add living space to these old basements and garages, and the space under these old entry stairs often became closets.
Once the framing under these stair systems was covered with plaster or drywall…the problems began. Because now the water intrusion events resulted in not only the soaking of the supportive framing, but the soaking of the plaster or drywall covers as well. And this of course eventually led to…mold growth.
I had an inspection this week at a 1950’s era home in San Francisco’s Noe Valley, and the front stairs were finished with a brick cover. Once the wood framing under brick stairs gets saturated with water, it’s going to support mold growth, and that’s exactly what happened in this home.
If your front stairs have developed leaks, several things will need to be done to address the problem. First, the leak(s) must be stopped! Until the stairs are properly waterproofed and the leaks have been stopped, there is no point in doing any repair or remediation work, but once the leaks have been halted, it’s time for the next steps.
If the leaks have been occurring for a long time, it’s very possible that any wood framing present has suffered rot, and any rotted framing will need to be removed and replaced. The demolition work should be done by a certified mold remediation company, and once the demo work has been completed, then a thorough cleaning of the surrounding area also needs to be completed. Once the demolition and remediation work has taken place, it’s time to have a licensed general contractor take over and complete the framing (and other) repairs.
As you can see, these stair problems can be a headache and can be very costly. But you ignore these stair leaks at your peril! Because the problem that exists today will only get worse if it’s subjected to additional rain and water intrusions.