I’m gonna dig out my crawlspace and make it match up with my basement, which has a poured concrete floor. It’s not in great shape (cracked and had tile on it at some point so it’s got asphault based adhesive on it). I was thinking about pouring a whole new floor, but then I thought what for? The basement is my workshop and I’d love to have a plywood floor. Could I just do all the normal waterproofing activities in the basement (interior drains at the walls, tough vapor barrier, gravel or sand) and then just build a wood floor using PT sleepers on the gravel/sand with T&G plywood as my “finish” floor? For that matter maybe I don’t even need gravel. Seems like the vapor barrier is the really important part.
MERC
Replies
Depends on how long you want it to last. Your crawl space has a full depth foundation under it? Why would they fill it half way up? Better check things out before you start shoveling.
No my crawlspace foundation is terrible. Looks like they got tired at that end of the house and just started throwing mortar and rubble in the hole and then hogged with brick, then finally got level enough to run block. I'm piering up the house using I beams and rolling a bobcat under there to clear the whole mess and dig down to basement level. Then I'll build up new block walls at full basement height.
*After* I do all that though, I'm wondering what the purpose of a solid concrete floor is, if any. Seems like some judicious sealing of a vapor barrier at the perimeter and I would have the critical component. Then I just need something on top of the vapor barrier to protect it from damage (like sand).
MERC
the cement helps to protect the vapor barrier.. plastic sheeting is not very durable sooner or later it would tear or punch a hole in it and there goes the protection.. you could use pressure treated and not worry too much about it but I'm certain when you go to sell you'll run into stiff problems..
If you aren't thrilled with humping all of that concrete in (and who woukld be why not just have it pumped in? Fairly inexpensive and a lot easier on the ol' back..
Doesn't the slab play a part in helping "key" the bottom of the foundation walls? Sure, they're pinned to the footings with rebar, but why not wear suspenders too?
I know that's true with treated wood foundation walls, anyway.
I agree...having the concrete pumped in is relatively inexpensive.
Yes, the backfill wants to push the walls in and the concrete resists the inward push.. Not the only way to do it, but probably the easiest.
If it were me I'd not use concrete block, rather I'd use those ICF's (insulated concrete forms.. basically styrofoam blocks that you pump concrete into.
I hate to hump concrete around and pumping it in is so much easier!
I think it would work fine. The vapor barrier, drainage, and insulation (to prevent condensation on cold surfaces) is the key. I do not think basement walls should be designed with any reliance on a concrete floor for structure anyways. Wood floor would have less thermal mass to heat up for occasional use. Easier on the joints.
There is a product being installed in the Fine Homebuilding archives. Click above and do a search for vapor barriers. #9 deals with a crawl space. Not exactly what you have in mind but it shows the care being taken. A concrete slab will add value to your property. Much more stable for equipment. Put down pads where you stand the most.
Not that this would happen at your place, but i replaced a floor like you describe for a customer. It was 12 yrs. old not pressure treated and really rotted from ground contact. Rats had made this a resort. When I first pulled up the flooring and saw the maze of tunnels I was scared. Bugs etc. like it there also. Humidity can sure be a problem for woodworkers.