GC put tar on 100% of foundation. I’m finding a lack of solutions for apperance fixes
Hey all,
My general contractor’s crew applied a black roll on tar on 100% of the exterior crawl space foundation. I know it came from Home Depot as that’s where they always went to get stuff, so I assume something Henry. It’s 100% visible from ground upwards to the sheathing. Not a great look.
I have contacted mineral paint makers, but no, their product must go on a concrete item like paraging or fiber board. I though screw on fiber board to paint, but no fiber board I can get is contact rated–in fact they say do not bury their product (USG/Hardie)
I’m not too interested in installing stucco mesh if there is a paint-able product that can go over the tar and be grey like parage. If there isn’t, I suppose screwing on wire mesh isn’t the end of the world, just asking if you’ve heard of something that is good to go on tar?
Thanks!
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Replies
What about concrete backer board?
Hey there,
Yeah, Hardie and USG say it's not ground contact rated. Possible problem would be it could de-laminate.
My experience is that mortar sticks to tar as well as tar sticks to concrete and you can parge over it.
You can also look at some of the roofing paints (ie Kool Seal). Most are designed to bond to bitumen and should work.
Thanks Akos. Since it's already fully tarred on the exterior, I suppose the fear of elastomeric paint does go out the window...
We ended up adding brown (but select color of your choice) painted flashing over our exposed foundation. Looks nice, actually.
Sorry, metal flashing? That's an idea...
Yep -- metal flashing. For most of the house, the idea is to cover/protect the exterior foam insulation that we have on the foundation stemwall, but there are parts of the house where code wouldn't allow it, so we just covered the concrete with the flashing to match. Flashed it right up under the siding (under the WRB, I believe).
This makes the most sense to me. You could even install some foam if you wanted (or pref rockwool). Then just spray paint it with metallic rustoleum and easily repaint if needed. Or buy pre painted, either way.
That's a really good out of the box idea I needed. Thank you!
Glad it might be of help!
I had a similar problem with my foundation - property slopes down and the back half of the house had damproofing (rubber/tar) exposed for about half the foundation height.
Previous owners had parging installed, but it continually delaminated, to the point that some former parging contractor actually chipped grooves into the foundation to try to get better adhesion - didn't last very long.
We also had a crack that exhibits small amounts of seasonal movement so that it would inevitably telegraph through parging, stucco, etc.
To solve these issues once and for all, we ended up using an elastomeric paint (BASF Masterprotect), which is waterproof, making the tar/damproofing unnecessary.
This paint will not adhere to the tar/damproofing though. So to prep the surface, I used a large diameter diamond wheel to grind off all the tar (it went pretty quickly) and then we hired a high pressure powerwashing company to blast the walls with about 5000psi to leave a surface with some tooth to promote adhesion (BASF recommends preparation to the CSP3 standard, which is a bit like 120 grit sandpaper to the touch). Powerwashing/blasting alone might be sufficient if you don't want to go to the trouble of doing the grinding.
The paint looks great and seems really well adhered. Most impressively, the crack that moves has not telegraphed through (we routed it about 3/4" deep, put in backer rod, then applied elastomeric sealant before painting). From a bit of a distance, the paint is indistinguishable from parging.
Thanks Patrick. I know concrete is strong. I know my crawlspace is to code. I know that it was sackcrete instead of from a truck shouldn't matter...that said, I have fears of hitting this area with a mechanical scuffer.