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I have a piece of beach front land that is sand (sometimes wet), what kind of foundation do you pour for a home constructed on sand?

What kind of considerations do you take in if its water front and could get wet?

I cannot find any info on this at all, anywhere... so if anyone has an example codes page I'd also love to look at it so I can know what to ask for here.

Cheers

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    You don't. You dig a hole until you hit something solid that's not sand, and pour the concrete on that.
    – iLikeDirt
    May 15 '15 at 22:14
  • Where on this planet is this piece of property?
    – DA01
    May 15 '15 at 23:54
  • Pilings... driven to depth where they have support. Jul 24 '15 at 20:47
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You don't construct houses on sand. Sand can't be compacted and, as such, will never be a solid piece of earth to place a foundation on top of.

Houses that are built on beaches are typically built upon concrete piers which go down to solid earth under the sand. Ideally bedrock.

As for what kind of foundation you need (or are even allowed to have) it will depend mostly on building codes in your area.

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There are multiple options for building on sand, but much of the answer depends on many other factors. Compact sand (to say sand cannot be compacted is erroneous, it just doesn't require much) can be a very stable base. We have built many homes, cottages and garages on land that is sand for 10s of metres deep.

Screw piles are one solution that works, but all that does is point load your home onto the piles, so you need a lot of them. We have had no problems with thickened-edge slabs, frost walls on reinforced footings and even full basement foundations further from the lake. Just talk to a local engineer to get your footings and or piles appropriately sized.

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I don't live on the beach, but we do live in a desert where the soil is essentially sand. I remember when we were having our house built, like everyone else has alluded to, we had to have the foundation dug very deep to where the soil was actually compacted and poured the foundation from there. The best place to find out about the mixture for your area would be the local government department of housing development as things like that vary a lot from city to city.

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I built my cottage over 45ft deep sand near a gradual sand beach. The water table is 2ft below the 24inches of compacted 3inch bedding rock we compacted before building the foundation. We built a slab on grade over top 8inch of rigid thermal insulation foam. We then shored the 8inch insulated slab with clear 1/2" to ensure nothing would move. The geoslab design was reviewed by our structural engineer and provided by our geothermal engineer. Yes you can build on sand.

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