lucgallant
New Member
Hi everyone,
I've got a question about a situation in my washroom. I know it's not a 100% plumbing question but it definitely ties to my plumbing system. I know it's a bit long but I wanted to provide all the detail.
See the attached photo.
This is a photo of a renovation I was doing 3 years ago. This photo is before I poured self levelling concrete. Today, the inspection hatch on the lower left is still accessible, and the inspection hatch on the upper right has been covered over, which I had discussed with my plumbing inspector.
In the lower left hatch, there is a check valve. This check valve separates the weeping tiles from my sewer system. This is looking down into it. Note that the 4" threaded cover is removed in this photo.
The configuration of my washroom today is, I've got the galvanized metal cover installed on the square inspection hole, and I've got sheet vinyl flooring laying overtop. I did not glue the flooring down in any way because I had to keep the check valve accessible.
The washroom has been finished for 3 years. When I recently lifted up the flooring for an inspection, I saw some black mould on the surface of the concrete and on the underside of the flooring. I lifted up most of the rest of the vinyl flooring in the washroom, and the mould is strictly between this square inspection port, and the nearest edges of the flooring. I cleaned everything with bleach and water and there aren't any signs of it left, except for minor staining on the underside of the vinyl.
My (unsophisticated) theory is that the air from under the slab is making its way along the slab/vinyl and leaving moisture behind which is turning to mould. I am 99.99% sure it is not water rising up as we would have seen it, and the area here is quite dry. My idea of a plan, is to apply a bead of acoustic sealant, between the concrete edge and a square sheet of vapour barrier. Then, rest the galvanized panel over top. So in the future it would still be inspectable however no air from below the slab could reach the flooring. This could be consistent with the vapour barrier installed on the underside of the slab.
The only other location where the underside of the slab exposed to the inside of the house is under the shower, however this leads up into the interior wall space so I'm not concerned about mould there.
Thanks in advance everyone for your input on this. I'm usually very versatile but this one caught me a bit off guard.
I've got a question about a situation in my washroom. I know it's not a 100% plumbing question but it definitely ties to my plumbing system. I know it's a bit long but I wanted to provide all the detail.
See the attached photo.
In the lower left hatch, there is a check valve. This check valve separates the weeping tiles from my sewer system. This is looking down into it. Note that the 4" threaded cover is removed in this photo.
The configuration of my washroom today is, I've got the galvanized metal cover installed on the square inspection hole, and I've got sheet vinyl flooring laying overtop. I did not glue the flooring down in any way because I had to keep the check valve accessible.
The washroom has been finished for 3 years. When I recently lifted up the flooring for an inspection, I saw some black mould on the surface of the concrete and on the underside of the flooring. I lifted up most of the rest of the vinyl flooring in the washroom, and the mould is strictly between this square inspection port, and the nearest edges of the flooring. I cleaned everything with bleach and water and there aren't any signs of it left, except for minor staining on the underside of the vinyl.
My (unsophisticated) theory is that the air from under the slab is making its way along the slab/vinyl and leaving moisture behind which is turning to mould. I am 99.99% sure it is not water rising up as we would have seen it, and the area here is quite dry. My idea of a plan, is to apply a bead of acoustic sealant, between the concrete edge and a square sheet of vapour barrier. Then, rest the galvanized panel over top. So in the future it would still be inspectable however no air from below the slab could reach the flooring. This could be consistent with the vapour barrier installed on the underside of the slab.
The only other location where the underside of the slab exposed to the inside of the house is under the shower, however this leads up into the interior wall space so I'm not concerned about mould there.
Thanks in advance everyone for your input on this. I'm usually very versatile but this one caught me a bit off guard.