[GregoryHP]

Hello – I’m a DIY homeowner (recently renovated 1895 row house in DC) and struggling with a small leak in my garage (brick walls, cement ceiling with a patio on top/roof). The patio on the roof has a storm drain connected to a PVC pipe that goes through the roof of the garage and carries stormwater to the rear alley. There is a PVC elbow immediately below the ceiling that drips water on the floor. It appears that storm water is seeping between the cement/concrete ceiling/patio floor and the PVC pipe. The source of the water is hardly visible, but this drip can fill half a bucket with one heavy storm. This leak has already ruined may painted garage floor, so I’m eager to repair the leak before replacing with a better flooring solution. I’ve read a lot about similar issues (usually in basement walls vice garage ceilings) but there doesn’t seem to be a consensus. Solutions that I’m considering include epoxy, caulk, and cement. I’ve read that caulk is flexible and will adjust with structure but that it’s a superficial and will fail. Epoxy is rigid and the watertight seal will break over time. Cement is also a superficial repair and that water will still work its way through over time.

I’m thinking that maybe this requires a combination of materials? For example, 1) apply band of hydrophilic paste/adhesive around edge of pipe where it touches the cement ceiling; 2) then pack hydraulic cement around the entire PVC elbow; and 3) apply epoxy adhesive where the edge of the cement meets the PCV pipe. Or is this overkill?

Also, what would be required for surface prep? I’m guessing that I should just clean the cement surface, and then sand around the PVC pipe?

Also wondering if I should reseal the exterior drain on the patio cement floor? The contractors used a PVC bell drain for some reason. Not sure how the flanging around the drain is sealed to the patio floor. Looks like the patio was recovered with a thin overlay. There’s already some cracking where the overlay meets the plastic bell drain.

I’m pretty handy and should be able to repair it myself, but need help identifying the correct material/solution first.

Here’s a list of products that I’ve ready are effective:

Quikcrete Hydraulic Cement (w/ foundation sealant?)

Polyurethane construction adhesive (high viscosity, wet and dry surface, fills hairline cracks, stretch)

Quikcrete Construction Adhesive

3M 5200 marine adhesive/sealant

Loctite Concrete crack ad masonry polyurethane sealant

Epoxy Sealant

Quikrete Epoxy Concrete Repair Sealant

Silicon caulk

Liquid Nails Clear small projects silicone adhesive

Butyl rubber sealant

Rubber spray seal

Rust-oleum leak seal or Flexi-Seal

Expanding foam

Urethan Grout injection (liquid expansive foam)

DAP Watertight Roof Sealant

DAP Watertight concrete filler

Plast-Aid Repair Putty

Would appreciated any advice folks can offer!

 

[diyorpay]

In my opinion, the storm drain is your issue (up top).
Any repair in garage area may last for awhile but is not the corrective fix.
Any way to reach into drain above?

 

[GregoryHP]

Thanks for your advice. Yes, the drive is accessible from the patio above. Attached are two photos with the grate on and off. I already sprayed FlexSeal on the inside of the pipe but that didn't do the trick. You can see the cracks along the square edges of the bell drain. One option might be to apply Quikcrete Concrete Crack Repair in those cracks and then paint over with patio paint?

 

[dj3]

The drain picture shows crack lines which form a square around the drain. Seal those cracks with flex seal caulking and test for leak.

 

[huesmann]

Gotta love the ghetto perforations on the cover.

 

[GregoryHP]

Agreed, it looks terrible. Originally, the contractors installed a nice channel drain that looked great, but leaked. After complaining to them, they replaced it with this bell trap drain thinking that it would be less likely to leak. That obviously didn't turn out to be the case. One advantage of the bell drain is that I could pull it up and put a permanent adhesive under the square collar (like 3M 5200 or roofing glue) and then use an overlay to feather in the edges to the surrounding cement. I suspect that it will crack over time due to weather and foot traffic. But if I replace it with a regular storm drain, then is that guaranteed not to leak? It seems like there are no easy ways to seal a storm drain in cement without it leaking.

 

[huesmann]

Do you know what the square is that's cracking?

 

[GregoryHP]

yep, it's a square PVC collar around a floor bell trap drain. Note sure why this was used for an exterior storm drain? Is there a better solution?

https://www.homedepot.com/p/Jones-S...Trap-with-3-in-x-4-in-Outlet-D42009/100194231