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Barn Basement

alex9999999 | Posted in General Questions on

Hello all, I am trying to put a floor in the basement of my barn in Western Mass., and would like to outline my plan and get thoughts on whether it seems sensible. I’m trying to make a workshop down there. Not trying to meet any code here, just going for somewhat comfortable and durable. 

It is a fieldstone foundation with good concrete footings underneath. Right now there is a dirt floor. Occasionally the soil seems a little damp. Having a slab poured was too pricey ($3,600).

I plan to:
-Dig down a bit more for more headroom
-Slope the dirt slightly to the outside edges
-Put a trench around the edges sloped to a hole in one corner
-Put down polyethylene
-Put a perforated pipe in the trench that leads to a 5-gallon bucket in the hole
-Cover all that with a few inches of gravel
-Put PT 2x4s on edge on top of the gravel, 16″ on center
-Rigid foam between the 2x4s, spray foam around the edges
-Lay a plywood floor on the 2x4s

If the bucket fills with water I’ll put a sump pump in it emptying to a dry well outside.

What do you think?

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  1. Expert Member


    I'd suggest a slight variant on what you are proposing.
    - Compact the gravel
    - Cover with poly (keeping the poly above the gravel allows it to act as a capillary break).
    - Lay a layer of continuous rigid foam.
    - Either PT 2"x4"s on the flat with a plywood sub-floor.
    - Or 2 layers of sub-floor on the foam.

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