PDA

View Full Version : Should exposed earth be filled with concrete?


cherylstrands
Nov 11, 2011, 04:50 PM
Upon opening up the wooden subfloor of our (almost) ground level suite, we found that previous owners broke up the concrete floor pad to add sewer pipes to get the right angle. There is exposed earth under the pipe and to one side. The dirt is ever so slightly damp to touch, but there is no water pooling (however, if you touch the earth with a kleenex it will get damp) but the surrounding concrete is dry. Wondering if the strip of bare earth should be filled with concrete or if that is necessary. I have had many conflicting opinions:

- leave and cover with poly (but that might cause mold)
- pour concrete (but the pipe shouldn't be encased in concrete and to do it properly you should rip open under the wall (and kitchen cupboard to get at concealed portion
- don't worry about the dirt, just make sure the outside is sealed
- moisture will always be present because of hydrostatic pressure, regardless of what you do from the outside

Any thoughts before I have the floor closed up?

Thanks!

Cheryl

ma0641
Nov 11, 2011, 05:02 PM
With the floor joists this close to the slab, it almost looks like this was an addition over a patio. Those cast iron pipes go back a way! The 2 right joists should be sistered, if possible, to strengthen them, that's probably what the shims are for. You could pour concrete over the dirt since you won't be encasing the piping. I would be more worried about termites with the wood so close to the floor. There is no visible evidence of water intrusion into the space.