Re: News story “Plaster Standard Out for Public Comment,” in the 6/12/2015 issue of Pool & Spa News.
We at onBalance would like to respond to a few points made in the PSN article. The statement attributed to the National Plasterers Council, that “onBalance concerns are based on research not pertaining to immersed plaster” is completely false. Our testing was done on core samples from failed pool plaster. That means they came out of real pools, and had been maintained underwater with real-world chemical conditions.
The forensic analysis laboratories determined in all cases we sent them that spotting and mottling on pool plaster was caused by elements of the plastering process, including calcium chloride content, the addition of water during finish troweling, and excessively late hard troweling. They also universally concluded that these defects are not caused by aggressive pool water. This research has been made public at no charge. Let’s stop allowing the NPC or its representatives from perpetuating this falsehood.
The statement that “supplemental water cannot be prescribed because of regional weather conditions” is completely untrue. Adding water to a hardened, smooth troweled surface and working it into that surface is not recommended by the Portland Cement Association or the American Concrete Institute or virtually any other authority besides the NPC — regardless of weather conditions. In fact, authorities specifically point out that “skewing the surface water-to-cement ratio” damages and discolors cementitious surfaces. The proper way to adjust for inclement weather is covered in ACI documents. Those documents do not recommend adding water to the surface. Some plasterers in the southwestern U.S. are trying to convince you that they need to do this. They are wrong.
The new draft plaster standard fails to address excess chloride. It fails to address water content, and wet finishing. It fails to address excessive late hard trowelling. If these specific issues are not even addressed, how then is this proposed new standard going to alleviate the problems we, as an industry, are addressing?
Why was the NPC allowed to totally control the content of an Association of Pool & Spa Professionals standard? They wrote it, they approved it, and then the APSP was only allowed to critique what the NPC decided should be in there. All proposals for edits involving additional material were disallowed because the NPC did not include those topics in their original draft.
There should be no rush to approve a poor attempt at a new APSP standard. There is every reason to get it right the first time. As the draft currently stands, it can and will be used to shift blame for failed plaster away from the culprit and onto innocent parties, including pool owners and service companies. These issues have never been “hotly debated” because the NPC refuses to discuss the lab findings.
We strongly recommend that all interested parties request a copy of the draft standard, and comment as you see fit. We have, and will continue to do so.