Earthquake retrofitting our historic home

Earthquake retrofitting our historic home

• 3.25.2022

Our basement renovation is moving along nicely! The first week was demo and getting started with the seismic staples/bolting the foundation to the house. This is something we have to do in Oregon because we get earthquakes occasionally, and in fact are expecting a large one sometime relatively soon (as earthquakes go).

Nowadays the building code requires you to attach a houses frame to the foundation, but in the 1930s when our house was built (and for many years after that too), that was not the case. The wood framing is just resting on the foundation or basement walls. The solution is to install special brackets every few feet around the entire foundation.

Seismic Strengthening in our Basement

It’s difficult and loud and expensive, but we actually have the best situation for doing it here. It is obviously much easier to do before you have drywall or any kind of finished walls installed in a basement, and it is much easier to do in a basement than in a crawlspace! Three of the four walls of our basement our exterior walls so it was very easy to get to them, and we had this step done first before any framing.

We got a couple of quotes back when we first bought the house and decided not to do it at that time ($5,500-10,000 I think), but knew that we really should before we added drywall! Also the quotes I got before were from places who specialize in this type of thing, including one who had a lot of very fancy marketing materials and a whole video he walked me through and everything, took more than an hour… the kind of place that you get the feeling is better at sales than being an expert in their industry. 

Fast forward to now, our contractor is doing a lot of work on this project and has experience with seismic retrofits but just charges his hourly rate, materials, etc., no marketing overhead. So we got a much better price working with our general contractor on this item ($2,815). It only took him about two days of labor to go all the way around our large basement

My dad has actually installed these himself in his basement! And I have heard about some courses teaching homeowners to do this themselves, because even before this crazy construction industry we are in now there aren't enough contractors doing this kind of thing to reinforce all the houses in the Portland area that need it! I just looked up some resources, here's one from City of Portland. It’s definitely more than we were able to take on right now though!

These photos are before our contractor had completed the seismic staples but give you a good idea. Since then he has also done a lot of framing on his walls and we’ve had the underslab plumbing dug out and installed. It feels right now like things are moving fast and I just can’t wait to start seeing walls in here so I can get to work on painting/pretty stuff! I’m sharing it all in real time on my Instagram stories if you want to see!