So I’m in the process of holding my house up for a new basement. This picture is a little old but I have the house completely on wood cribbing. My question is if anyone else has done this or seen it done in any kind of wind? We are supposed to get wind gusts of 45mph next week and it makes me worried…. I believe everything is stable but I obviously don’t want to lose my house. Any info or suggestions is much appreciated thanks.p.s. I know you need to be a professional to do this I don’t need to hear that. I got input from multiple people on engineering and what needs to be supported/load bearing… They just don’t know about wind and what this could do to the house up in the air like this.
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I was just rewatching the TOH episodes about the Carlisle project, and they lifted the whole, huge barn on cribbing, and then mentioned storms. I thought to myself, I wonder what the wind loads on that structure are and how it will stay on the cribbing. It did. https://www.thisoldhouse.com/carlisle-house/21014861/barnjacking Will be interested if anyone who knows what they're doing can chime in...
At this point, if you want to do something, you could put a couple of those loose CMUs on the floor above the bearing points.
force of the wind scales with the square of the wind speed.
Most of the wind calculators online start at velocities over 100mph. (and are pretty complicated)
a 45 mph gust would give you forces 1/4 of those from a 90 mph wind.
From the looks of the picture, the house is not lifted as much as it is held where it was with the cribbing so that a basement can be dug underneath. I have not seen this approach exactly before. We did move a house onto a site, build a new basement, and then move the house onto the new basement, but as far as I know it never saw high winds.
As far as the 45 mph wind, this is a strong wind, but fairly modest as far as design loads go. (Most places might see a 45 mph wind every 5 years or so, maybe more). Mike is correct about this being about 1/4 the load of a "design wind"
Most, if not all of your wind resistance comes from your attachment of the exterior walls to the foundation. I can't tell from your photos if your walls are still attached to your original crawlspace walls or not. If so, you should be in pretty good shape as-is. If not your best bet for adding some strength would be to use something similar to trailer tie-downs (Edit: Mobile Home Tie-downs) at the corners of the house. Focus by tying down the corners of the exterior walls parallel to the direction the wind will likely come in from.
How exactly you attach the tie-downs to the house will be the tricky part, but since you have finishes removed you might be able to nail off steel strapping directly to the outside of the house.
Out in Long Island they've been raising houses above flood plain ever since Sandy came through. Most guys do nothing to tie the structure down they sit on cribbing exactly like yours until the new foundation is done and
I haven't seen one fall yet.. You could always install some earth augers and use ratcheting straps to tie the house down. In the scheme of things it wont cost too much and it will give you piece of mind.
If your foundation walls are still in place you could install strapping from stud to foundation very easily.
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