PoolQ I just had a swimming pool built and everything I have read online says that the gunite shell has to be sprinkled with water for several days after the pour. My pool builder says they never do it, and, when I asked why, I’m just told that’s the way they do it. I told them I am worried because every other pool builder says to do that except the one I hired and I can get no answer as to why. Is this an acceptable practice? I am worried that years down the line I may have a problem. I live in Oviedo, FL, and the weather has been in the low 70s and the humidity not particularly high. They did hit the water table and have a pump running—would any of this have an impact?
ASA recommends a minimum of 7 days curing for all exposed shotcrete surfaces. Wet curing is preferred to supply additional water to the concrete surface. If a spray-on curing membrane is used instead of water curing, the material should be applied at twice the manufacturer’s recommended rate for formed surfaces. Curing is important to allow the concrete to develop as much strength as possible and to help resist cracking from internal shrinkage of the concrete. Low humidity, wind, and exposure to sun will increase the need for proper curing. If the site is dewatered, the groundwater is below the concrete work, and not effective in curing the exposed shotcrete surface. The American Concrete Institute (ACI) has an excellent reference, ACI 308R-01, “Guide to Curing Concrete.” It appears your contractor is not following the industry standards as documented by ACI.
