After 16 years, I have rough spots in my in ground concrete pool. What would work as a quick fix for the worst spots to get me through the summer without draining the pool?
I plan to renovate after the season.
PoolDoc
04-30-2019, 08:14 AM
Like spalling? See https://www.google.com/search?q=concrete+spalling
If that's the problem, you can make a 1-season repair using thin concrete patch techniques: https://www.quikrete.com/athome/video-thin-repairs.asp
BUT . . . that sort of patching takes a fair bit of manual skill.
FWIW, spalling is caused by adding too much water to the concrete mix when pouring. In other words, it's an original defect. The problem is, concrete is much easier to 'finish' when it is 'soup' then when it is 'stew'. And, contrary to what most people thing -- including many concrete workers -- concrete does not "DRY" but "CURES CHEMICALLY", by reaction between the cement and the water. The amount of water needed for reaction is very small: properly mixed concrete that has minimal water will be extremely 'stiff', requiring special techniques to pour and finish. Additional water is added for finishing, but every bit of this water creates permanent voids in the concrete. Engineers specific concrete slabs with '4" slump' -- a moderately stiff concrete -- but finishers and pool builders often pour 'soup' that is 12" slump! This concrete is very porous, and suffers from winter freeze/thaw cycles, producing spalling.
A 100' x 100' deck I poured 20+ years ago, in a VERY exposed location, still has ZERO spalling . . . but only because I spent the entire day on site, yelling at the finisher every time he tried to add excess water. He was pretty unhappy with me, when they finished up about midnight!
It's more like sand paper than spalling. I am considering trying a rub brick from Home Depot.
PoolDoc
05-03-2019, 10:57 PM
Arg-h!
My bad. You said "IN your pool" . . . I read "AROUND your pool".
Rough plaster is usually caused by a combo of low pH and poor finishing. If it was ALL rough, low pH would be the likely primary cause. Rough in spots points to poor finishing as primary. A rubbing brick can help. I'd recommend staying away from the Chinese 'in-stock' bricks going by brands like "Anvil" and "Bon". Instead, go with US pro brands Marshalltown or Goldblatt: the difference is only $3 or so. Keep in mind that these are VERY brittle, and WILL break if you drop them onto a hard surface -- US-made or not!
Marshalltown rubbing brick (http://www.amazon.com/exec/obidos/ASIN/B000GATLWM/poolbooks/)
Goldblatt rubbing brick (http://www.amazon.com/exec/obidos/ASIN/B00002X2DH/poolbooks/)