Does anyone know of a product that will provide a “vapor Barrier” on the inside surface of the exposed wood deck in a pool environment? I am looking for a clear coating that will have a perm rating of less than 1. HELP please
Yummm! The many joints in the wood deck will work just like a razor works on a vapor barrier sheet. Can’t seal them, so don’t try. You should put the vapor/air barrier above the wood deck, and put enough insulation on top of it to keep the dewpoint outboard of the vapor barrier year round. It’ll be a bunch of insulation, because the relative humidity inside the natatorium will be … rain. Time for a WUFI analysis. Don’t forget the stainless steel fasteners and lintels and negative pressure HVAC and all that other pool stuff.
Mitch,
I second Phil’s reply and must add make it an air/vapor barrier connected to the wall air/vapor barrier connected to the foundation air/vapor barrier/waterproofing connected to the under slab air/vapor barrier.
Seekout Joesph Lstiburek’s article “THE PERFECT WALL” in the May 2007 issue of the ASHRAE Journal or e-mail me at wayne.yancey@callison.com and I will send you a PDF verison.
What Wayne is talking about is really an air barrier, which is very happy to be the same membrane as the vapor retarder, though it doesn’t necessarily have to be. If they’re not, make sure that the dew point analysis and permeability of the two support the locations chosen for each.
Wayne, isn’t the title of the article,
“The Perfect Storm Over Stucco”
We use a 40 mil sheet such as WR Grace Ice and Water Shield over the timber decking, then the diaphragm plywood (to protect it from the moisture) then nailbase insulation with XPS instead of ISO. That is our standard over pools & waterparks.
To Anonymous,
No.
E-mail me and I will reply with the article I quoted.
Wayne:
The full, unedited, and updated article can be downloaded via buildingscience.com:
Ron,
Thanks but I know this. That is the source for my Building Science Corporation articles by Dr. Joe.