I specified GP’s DensShield for the walls and ceiling of a Spa within a new hotel. Most of the surfaces will receive tile or stone finish. The Contractor decided to use standard type-x gyp board for the ceilings, ignoring the specs. Why he followed the specs for the walls has yet to be explained. The Architect asked if there is any coating the GC could apply over the gyp board to render it mold resistant. I said no, tell the GC to rip all the gyp board ceilings out and start over, this time following the specs - I’m not fond of this GC or this job. What really ticks me off is that the GC is blaming the specifications for not clearly stating where the DensShield was to be used…I specified it as a backer board for wet areas, and since in the center of this spa is a huge communal whirlpool, the spa is a total wet area. The architect’s drawings were not clear in defining which surfaces are to receive DensShield. The Architect’s solution is to retain the existing ceilings painted with an epoxy coating. Why is it Architects think Epoxy is the cure all for what ails you?
I like my answer, but my client thinks I can do better. I will explain further by telling you the Spa is a few 100 feet from the Ocean in S. FL., the drywall will expand and contract along with the joints. I don’t see how a coating is going to make this assembly mold resistant when the substrate isn’t. And of course the Developer wants the least expensive solution. Any suggestions would be appreciated.
One more thing, most of the interior walls are covered in DensShield, more than was required, perhaps the GC used up all the DensShield on the job for the walls and figured the ceilings would be ok with standard gyp board.
You could have the contractor ADD a layer of moisture resistant drywall instead of demo’ing what’s in place. Curious, is the soffit/ceiling framing at 12" OC? Might need to be.
Alternatively, you could perhaps use a high performance anti-fungal primer like Kilz, and then top coat it with another quality paint coating that is anti-fungal, but all you are doing is making the food source for mold hard to get, not absent altogether.
No reclamation bins on this job that I know of.
No non-compliance report for me to write, I’m not the architect and the Developer refused to pay me to be available during CA, any time I spend to answer questions like this one is pro-bono.
This job has been a nightmare from day one, this is the developer who told the Architect that the Project Manual was too thick, at 4" double sided, he demanded we reduce the thickness to 1-1/2".
Welcome to S. FL Architecture, for all you M.A.S.H. lovers, its meat ball surgery every day.
You also need to worry about the backside of the standard Type-X. The good mold and moisture resistant products have improved backs and cores in addition to the upgraded face of the sheet.
I have never worked in Florida, but if the ceiling is in a pool/spa area on one side and unconditioned Florida air is on the other side there will be damp.
GC has offered to paint the gyp board with a SW Harmony Interior Latex Semi-Gloss paint, wow, this job gets better and better.
Steven you are correct, its not just about the facing.
What blows my mind is the GC thinks that he has complied with the Specifications, but than again the Developer did throw the revised and shortened specs in the trash bin at start of the job, apparently when bound, the Project manual measured 2 inches, my bad.
Nathan, wooooosh
I don’t understand, did I miss something?
What has bible paper to do with my job, is this some sort of religious joke?
Please enlighten me?
If your product is being measured by thickness instead of content, and you have to get down to a certain arbitrary value of less than 1.5", you could use Bible Paper (AKA: India Paper, lightweight offset paper, premium book paper) to accomplish that. Here is another link: http://desktoppub.about.com/od/glossary/g/biblepaper.htm
Seriously Nathan, I refuse to ever meet the ridiculous requirement of Project Manual thickness ever again. I will be the first to agree that Project Manuals are too long, but I can’t believe anyone would need to measure the thickness of their Project Manual in order to appease a client.
However, I enjoy learning new things, and I’ve never heard of Bible Paper, so thanks for that info.
Tnemec Company, Inc. has a system that would protect the exposed surface from mold and mildew, but as stated above, that does nothing for the core and back face. The Tnemec system is Series 151 primer and Series 158 top coat. Verify with your local Tnemec rep.
On a more serious note, what is above the ceiling? Will it be ventilated? Cooled? If it ventilated and hot, you may be able to avoid condensation in or on the gyp board.
There was an article in the CSI magazine many years ago about “Natatorium” failures due to moisture and corrosion issues. I last remember sharing it with a client for a project with an indoor pool way back in 2005 or so and I recall it took some search for it even then. It might be worth tracking down.
Some scary stuff like a structural roof failure and some bizarre stuff like a wall-mounted stainless steel clad drinking fountain that looked fine at first glance but when you opened it, all of the interior components had rusted away to a pile of junk in the bottom of the enclosure.
Steven, I know that article, by Catherine Houska, I have a PDF on file as I’ve had to specify stainless steel pools and hot tubs on high rise coastal projects. The article talks mostly about using stainless steel for pool construction, not really Natatoriums, all the pics in the article are open air pools.
I would be scared to death to specific a Natatorium, thankfully I’ve not had that opportunity as of yet.
Most of the GYP BD manufacturer reps I’ve reached out to recommend applying a mold resistant board over the existing drywall, no one is willing to offer an off the record out of the box solution, can’t blame them, I still like my solution of tearing it all out. Its up to the architect and engineer to figure out if the installed framing system can support the added load.
Robyn, please send me the info, I will reach out to the manufacturer as I am interested in their warranty and limitations. Warren Barber from National Gypsum just emailed me some suggestions which I am reviewing. Warren’s comment: “If you were to coat the face with Customs Red Guard or Laticretes Hydroban as a water proofing coating, it would keep moisture away from the board, No moisture, no mold.”