Wednesday, June 27, 2007

Foundation issues

There are a bunch of inconsistencies b/w the engineered drawings and the as-built version of the foundation. They are not dealbreakers (the dimensions are correct, and it's square), but it's disappointing that the contractor didn't follow the plans and that I didn't catch them.

This is going to get technical (and boring unless you are really interested in the nuts and bolts of this process). After Res4 designs the house, they have a third-party engineer draw structural details to comply with applicable code (no code in Hardy County, WV, but most builders build to BOCA; I don't actually know what code the engineers drew to in our case). The engineers look at shear and lift concerns and make sure the house is up to snuff. With our house, the connections to the foundation present some lift issues (how to keep the house connected to the foundation when wind wants to lift it off). So the engineered plans specify the kinds of connections that are required b/w the house and the foundation: a combination of anchor bolts (which connect the sill plate - the lumber cap on the foundation - to the concrete wall) and straps (which connect the house to the foundation) and other anchor bolts (also house to foundation), the precise deployment of which varies depending on which specific materials the builder uses. In our case, for example, the engineered drawings offer four different sets of specs (specifying frequency and distance) for the anchor bolts to the sill depending on which kind of bolts are used. The anchor bolts for the sill and the corner straps specified on one of the short walls of our house needed to be located and set in the wet concrete of the foundation wall during the pour. Some of the anchor bolts were missed, and the straps were not set.

Res4 noticed this in the pictures I posted on the blog (another great reason for blogging this process - your architect can monitor progress remotely) and contacted me to talk about implications and possible fixes. Most importantly, structurally the house will be fine. We can compensate for the missed straps in the foundation by increasing the number of straps on the exterior (connecting house to foundation). If there were an inspection process, it would probably be a bigger deal - new engineered plans might be req'd and we'd have to wait for approval.

After talking with Res4, I talked with the contractor who is managing the pre-set and set phases for us. His position was that the connections all exceed BOCA (which is what he builds to) and they've already gone above and beyond what is necessary; in his words, "it'd take a hurricane to move this house." That, of course, is not an acceptable answer for deviating from the plans without talking to me, and I told him as much. We talked about the strapping that Res4 recommended as a solution. He said we could do what we want but it's fine as is.

Lots of lessons here. First, as difficult as it is to get your arms around the technical specs of the building process, learn as much as you can. I probably didn't do enough to educate myself about the particular details of the engineered drawings (I knew there were connections called for at the corners, and didn't know better that the anchor bolts the contractor used weren't those called for on the plans). At some point you're trusting your builder, and this is probably one of those areas, so choose well. (This is also one of the areas where prefab becomes a factor - I've got a builder I don't necessarily love and I'm not there as much as I'd like to be, but I'm not relying on him to do nearly as much as if he were building a whole house for me.) Review as much of the technical specs as you have the stomach for with as many people as you can. I'm sure Res4 would tell you that I've asked more questions than they usually get, but there are still so many things that I don't know.

Second, there's a HUGE difference b/w drawing a house and building a house. There's a lot of standard building practice that isn't done exactly as an architect or an engineer would have it done, and at the same time there's a lot of sloppy building. It's nice for me right now to have Res4 to fall back on for a little more perspective on which is which.

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