Hi guys, new to forum and house construction... building a 16" x 54" addition to my house. Its all excavated (I have a basement house) including around the existing house to redo the drain tile and waterproofing. Below ground I will be doing surface prep, waterproofing, roxul drain board and then filter fabric/protection board as needed.

How do I prep my existing foundation for waterproofing? There are some spalls, holes, and a couple hairline cracks. I very well may get a contractor to do the work but if I can get things moving I will.

How "smooth" does the surface have to be? My existing foundation is not smooth at all... and the surface at the top of the footing is very uneven and inconsistent. the foundation on my addition will be much better naturally!

Where do I even start? How dry does the surface have to be to apply a waterproofing membrane? We are at the start of rainy season here in Surrey, British Columbia - should I attach poly to my siding and cover the foundation until I get to the waterproofing? I like the Bakor/Henry line of products or I might get the Tremco Tuf-n-dri done by a contractor.

Any advice would be much appreciated.

 

Scrape whatever you can & dry it with a good size torch, about an hour before you are ready to apply the membrane. If there is vinyl siding near by, don't set it on fire. That stuff is so flammable, it should be illegal.

 

tremco's a good process but we use basf/sonneborn hlm5000 applied w/16" scrub brushes & 19mm pond liner over it for mastic protection,,, from what i can tell, henry MAY have a decent foundation/wall coating but still awaiting rep's tele call,,, elastomeric is the keyword w/any wall coating,,, for thin crks, probably no repair will be necessary

 

Thanks. You have given me some products to research. Any thoughts on blueskin self adhered membrane?

 

never heard of it - is it like bituthane ?

 

Blueskin 200

 

personally, i like scrubbing in/on a coat of the hlm5000 then hanging 19mm pond liner as backfill protection,,, we do this work professionally however its always retro work & i HATE callbacks ,,, we don't solicit new construction as bldrs wouldn't pay the costs as bldg codes don't require waterproofing

seam sealing has always been an issue w/cast sheet membranes,,, i've been doing this work too long & prefer tried & true stuff