I’m in the process of starting a storage shed. The site is not level. The building will face east. The area drains from the front (east side) to the Back (west side). I was going to build a “on grade” foundation of solid concrete blocks. My first work in the area was to strip some of the soil and sod. This decreased the slope when I removed more soil from the front side and less from the back side.
Can I lower the front pressure treated foundation below ground level? With a 2X6 foundation, it will be a jump to move the lawnmower into and out of the building. I was thinking of “protecting” the PT lumber with a “Trex-type” deck board between the soil and the rim joist.
Any suggestions would be appreciated and I sorry but I hope this explanation is clear enough to follow. Thanks
Replies
Also, do you have troubling finding PT lumber other than "above ground" grade lumber? Thanks again
I used pier blocks rather than a foundation as such.
That is, I placed these concrete blocks on appx. 4 ft. centers, recessing them as necessary to be level with each other. I then built my shed atop them.
As built, the shed floor is about 10" above the lowest part of the yard. Were I to have made a few minor xhanges, I could have easily cut that in half, and still not had any wood directly in contact with the year.
I like this arrangement so much, I'd consider setting them in a pit if I wanted the floor actually level with the ground.
That last comment makes me realize .... I suspect that drainage is an important issue. Good drainage ... say, a gravel base ... would probably make a world of difference.
The problem will be having siding and sheathing close to the ground. For a shed, I prefer to have a framed floor up on blocks in the corners and where else needed, according to size. You don't need blocks under the whole floor. Double rim joists. Build a ramp up to the floor level. It's easy to jack and shim as the years pass and things may settle. You can also move the shed if you ever want to. Don't cheap out on the floor construction and keep it off the ground 3 inches or more.
Beat it to fit / Paint it to match
"Don't cheap out on the floor construction and keep it off the ground 3 inches or more."The floor or floor joists -- 3 inches or more?Yes, I'm planning on a 2X6 joists and beams with the perimeter doubled up. Advantech for the floor."The problem will be having siding and sheathing close to the ground."I agree with the sheathing but since it will be a LOW maintenance structure -- vinyl siding.Do you overlap the sheathing over the "foundation"? OR the subfloor?
Edited 7/9/2009 9:46 am by Faulted1
For a small shed at or near grade I like to do away with the problems of wood floors framed close to the ground.
I prepare the area underneath by laying 6" clear crushed gravel.
On top of the gravel I build a perimeter out of 6"x6"pt. lagged together. The top is a couple of inches above finished grade.
For a floor I use patio stones on more compacted clear crushed.
Walls and roof sit on the perimeter beam.
Nice and low for easy access, nothing to rot, low maintenance floor, easy to move.
For a sloped grade, you could build a little platform on posts in which to put your shed on.
Of course this takes a little more work, but then your shed sits flat and in the location you're happy with.
Dig four holes, roughly three / four feet deep, insert four 6 x 6 pt posts (sitting on gravel), backfill and compact the dirt as you go. Frame your platform as you would a house (rim boards, joists 16" O.C, 3/4 plywood) then just plop your shed onto your new, flat deck. Use all pressure treated wood.
Any sections that might be too high can be covered by lattice to keep animals out, or just conceal the "un-even-ness"