Wednesday, October 04, 2017

A deck update.

This morning brought good news. They'd gotten all that tile off and stripped the pony walls to find they were in really good shape. But we also discovered a waterproof membrane. Which is one of the best ways to fix this problem. Or so I thought. I thought those things were suppose to last forever!

Apparently not. But it gets better! Once the membrane was stripped we found another concrete slab underneath that is about 3-4 inches deep. So they are up there with the jackhammer again today. At least I hope I'm teaching my neighbor that I too can be super annoying.

But more seriously - it is not an exaggeration at all that this deck could have collapsed on me. It had between 7 and 8 inches on concrete on it. I'm super lucky.


  1. 90 psf of concrete shouldn't be sitting on a wood frame over a garage, which is what you've described, more or less.

    Residential decking is usually built for a 40 psf load or greater.

    But in order for this absurdly built project to get done and not fall down, the people who built the frame over-engineered it so it probably holds 120 psf as long as the dynamic loads are minimal.

    In other words, you knew not to jump up and down on it. :-)

    I've seen post and beam construction (smoke houses) that wound up being repurposed into storage areas. The civil engineers figured the flooring was good for 120 psf, and so they made the owners stick warning signs all over it about maximum loads that were for static loads. Typical commercial codes in that region mandated a minimum of 200 psf in non-earthquake-prone areas and 300 psf in earthquake-prone areas, but it got approved for storage use anyway.

    Every time you have an earthquake, however, you are at risk of exceeding what I suspect are extremely tight dynamic load limits.

    Now that the project is under way, I wouldn't stick your head up under there to take pictures of the frame, but that might have been interesting just to see it.


  2. Wow. And that's not counting the tile that was up there too. And I've woken up to an inch of water up on it. In the winter I need to check the drains two times a day because of their hack job.

    I very likely could have been right at the line. I had become pretty nervous about that deck (i.e. listening for sounds when I walked on it) but seeing that second slab put a few butterflies in my tummy. That is a terrifying amount on concrete.

    My contractor is going to give me a weight total. He said 5000 pounds easily. I could have put a car up there for effs sakes.