I'm a DIYer in-ground pool/spa guy in Goodyear, Arizona. And, thanks in advance for reading my exhaustive explanation of my problem. I've built with CMUs with #4 and #5 rebar and all fully filled cells. Built on rebar reinforced slabs (12" thick for pool, 20" thick for spa). Slabs have a 20 mil pvc sheet underneath and Henry's dampproofing on outside edges of slabs and outside of CMU walls. All this was prescribed by a structural engineer in the planning stage. Interior walls were then covered with about 1/2 inch of stucco, then a thin coat (1/8" including a dashed texture) of thinset mortar to finish. Everything is cured out (more than 90 days), but I'm still getting really high moisture readings (30% and more, measured with a Wagner L606). My preferred waterproofing membrane is one with elasticity vs a cementitous membrane. I've attempted to use SEMCO, but have had some problems with it fully curing because of the moisture content (they wanted it to be about 3%). In addition, because the initial application of the liquid membrane was done on a substrate with too high a temp (not cautioned in anyway by SEMCO unfortunately), the membrane has a lowered adhesion to my substrate. I'm now faced with peeling off the membrane and going at it again. Per SEMCO's recommendation, because of the high moisture content readings, I also initially applied their own brand of penetrating sealer (on their recommendation) before applying the initial coating of liquid membrane. They are recommending I apply MORE coats of penetrating sealer (after removing the current liquid membrane) then reapplying their liquid membrane again. I'm a bit confused by that since it didn't seem to help the first time... but this area is a bit beyond my pay grade. After my waterproofing membrane, I plan to cover about 80% of the membrane with recycled glass tiles and grout. Can readers please weigh in on the moisture content issue and any recommendations? I'm a little concerned about 'trapping' so much moisture inside the slab/walls if I have waterproof membranes on both sides. I know that a cementitious product (like Laticrete Hydroban) might be a more suitable membrane since it would work with the underlying moisture to cure... but alas... it doesn't have any elasticity factor (which I'm thinking would be good for any future movement/cracking that might occur in the whole structure -- the SEMCO has a 1300% elasticity). Thanks for any wisdom you can share.
Waterproofing membrane and concrete moisture
- Thread starter Nateski
- Start date
P.S. The use of a cementitous membrane (instead of SEMCO) may not even be possible now, as it would require trying to remove the penetrating sealer on the substrate... a daunting (if not impossible) prospect.
P.P.S. I've got TONS of pics of my process if anyone wants to see them. Seems like that's inspiring to a lot of people... but don't want to cloud this post up right off the bat!