Basement Foundation Waterproofing, what to backfill?

Hey folks, looking to build consensus on how to approach waterproofing this corner of my home. I’m a sucker for punishment and excavated around this problematic corner of my cinder block foundation by hand, to have a look at the waterproofing that was applied by the previous owners (maybe 15 years old). They used Blue Skin, with a 1” thick foam insulation board. There is clean gravel and a filtered o-pipe weeping tile/french drain in the bottom, which I will assume flows out to storm drains towards the front of the house, frame left. Not sure if any rubber paint/ tar was applied to the block. The system definitely seems compromised, or inadequate.. Inside this corner, 10x10 feet, is my home gym room that has had quite a bit of efflorescence flaking out a coat of paint which I have now removed with a belt sander. I see some cracked parging cement. When it is really rainy and wet outside for an extended period of a few days, the wall feels wet to the touch, but it isn’t leaking like a faucet.. I would love to be able to paint the inside wall again, but maybe a plastic wall covering is a better bet, long term. My plan on the outside is to rip off the blue skin and foam board, apply layers of rubber paint to the cinder blocks, then screw in a new roll of solid plastic dimple membrane.. termination bar up top. Hopefully, this doesn’t introduce any new water intrusion, by breaking the seal of the blue skin.. I got an inspection + quote from a contractor who essentially said ^ would be their plan, for $4350cad. Here’s where I need help, to build some consensus, what should I backfill this trench with? There was a fair bit of clay before which I really don’t want to put back in as it holds so much water…. I’ve read that a mix of soil / sand is best to backfill against the foundation to help the blocks bear weight & prevent shifting.. and soil is best on the very top to help grade surface water away from the house. I was planning on dumping about 4 yards worth of 3/4” washed gravel stone in the bottom, maybe with a new layer of landscape fabric acting like a burrito wrap. Maybe 1-2’ of soil back in on top of the gravel. What do we think?? submitted by /u/lazajam [link] [comments]

May 10, 2025 - 20:57

Basement Foundation Waterproofing, what to backfill?

Hey folks, looking to build consensus on how to approach waterproofing this corner of my home.

I’m a sucker for punishment and excavated around this problematic corner of my cinder block foundation by hand, to have a look at the waterproofing that was applied by the previous owners (maybe 15 years old).

They used Blue Skin, with a 1” thick foam insulation board. There is clean gravel and a filtered o-pipe weeping tile/french drain in the bottom, which I will assume flows out to storm drains towards the front of the house, frame left. Not sure if any rubber paint/ tar was applied to the block. The system definitely seems compromised, or inadequate..

Inside this corner, 10x10 feet, is my home gym room that has had quite a bit of efflorescence flaking out a coat of paint which I have now removed with a belt sander. I see some cracked parging cement. When it is really rainy and wet outside for an extended period of a few days, the wall feels wet to the touch, but it isn’t leaking like a faucet.. I would love to be able to paint the inside wall again, but maybe a plastic wall covering is a better bet, long term.

My plan on the outside is to rip off the blue skin and foam board, apply layers of rubber paint to the cinder blocks, then screw in a new roll of solid plastic dimple membrane.. termination bar up top. Hopefully, this doesn’t introduce any new water intrusion, by breaking the seal of the blue skin..

I got an inspection + quote from a contractor who essentially said ^{^} would be their plan, for $4350cad.

Here’s where I need help, to build some consensus, what should I backfill this trench with? There was a fair bit of clay before which I really don’t want to put back in as it holds so much water….

I’ve read that a mix of soil / sand is best to backfill against the foundation to help the blocks bear weight & prevent shifting.. and soil is best on the very top to help grade surface water away from the house. I was planning on dumping about 4 yards worth of 3/4” washed gravel stone in the bottom, maybe with a new layer of landscape fabric acting like a burrito wrap. Maybe 1-2’ of soil back in on top of the gravel. What do we think??

submitted by /u/lazajam
[link] [comments]