Cabin Foundation

[Gapinspect]

We recently purchased a cabin in central Canada. The foundation (which is identical as all the neighboring cabins) is simply wood blocks on the ground. The soil is primarily sand. I want to raise the cabin to approx 3' from ground level and insulate the foundation walls. Drilling piles to below the frost level in is near impossible due to tree's and an attached deck. Would a post and pad application be suitable here being that we are on a sand base? Talking to neighbors, no-one seems to have a problem with there cabins on wood blocks. Any suggestions?

 

[DRC1]

There is a lot to be said for the obsevational metod. If the cabin has been there a while and it is on sand, the ground is firm and drains away from the cabin, I would say you are probably okay. It is difficult to say for sure without seeing the site, but it sounds like it works. I would suggest using concrete instead of wood, as the wood may rot, attract insectsand have lower strength. The Concrete will last for a long time

 

[msquared48]

I assume you are not in a high seismic or wind load area?

Mike McCann
MMC Engineering

 

[RVSWA]

Is the wood pressure treated? If you don't have a ground water condition, you may not have a problem with rot for quite some time... With a reasonably deep frost depth, you probably don't have a great deal of exposure to wood boring insects. As a precaution, carefully document the condition of the foundation and make careful observations every two years. Now tell us more about these trees, are there two trees close enough and large enough to support a good hammock?

 

[jrh009]

I would suggest starting with the local building dept. If you deviate from Part 9 of the National Code you will require a designed foundation by a P. Eng.

Part 9 will require a concrete footing below frost unless the soils are non frost susceptible. Concrete piers or masonry pier blocks on the footing to the underside of the supporting beams.

I assume you are referring to a small 600 sq ft bldg and not the monster 6000 sq ft cottages in my part of Ontario.

Start with the building dept, they are excellent sources of free information, and you will have to deal with them anyway.