Subscribe or Renew Membership Subscribe Renew

Recommended Floor Construction - House on Piers

WalpoleJoe130's picture

Hi - Long time reader of Fine Homebuilding.  I'm considering rebuilding a lake house in south-central NH.  The house would be close to the water and a very high water table so was leaning toward building a house on piers with 2'+ between ground and underside of floor assembly.  I'd appreicate anyone's thoughts and recommendations for the floor assembly.  How much insulation do you recommend?  Any thoughts on the best way to finish the underside to prevent critters from sneaking in? Where to install the vapor barrier?  I'm not a builder, but would like education before I talk to potential contractor.  Thanks!

This is basically no (post #215389, reply #1 of 3)

This is basically no different from building a regular house with a crawl space.

Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

acritter access... there is (post #215389, reply #2 of 3)

acritter access...

there is the trick


TN state park cabins had 1/2 ply across bottoms of joists, big holes eaten thru. 


So,  metal sheets or cement board or hardiboard to close off the bottom. 


I had squirrels eat thru 1/2" T-111 and edgewise thru a 2x4 to get in thru a wall! , dumb squirrles did not know to move to one side to miss the 2x4! 

Thanks for that information - (post #215389, reply #3 of 3)

Thanks for that information - I like the idea of a hardiboard or metal sheathing across the bottom of the joists - I do worry about stupid squirrels...


Any thoughts on insulation type?  I hear that air infiltration is the biggest contributor to cold floors so I was thinking that using closed cell foam at least to seal off the interface of the subfloor and joists.  Thoughts on using closed cell full depth of joists?