| Author |
Message |
Robert E. Woodburn, AIA, CSI, CCS, CCCA
Senior Member
Username: bob_woodburn
Post Number: 85
Registered: 11-2010
| | Posted on Friday, June 06, 2014 - 03:26 pm: |    |
I was just asked, "...can you please investigate the absolute BEST negative side vapor barrier possible for use with a gym floor?" This would apparently be for use on a slab poured over an unsubmitted and unapproved substitute vapor retarder, in an attempt to regain the difference in impermeability. The specified product's permeance rating was 0.0011; the product reportedly used is 0.0081--a 7.3x difference. (Yes, I realize that "absolute BEST" is not the absolute best terminology, but perhaps there is one...) Suggestions? |
ken hercenberg
Senior Member
Username: khercenberg
Post Number: 767
Registered: 12-2006
| | Posted on Friday, June 06, 2014 - 03:38 pm: | |
Hard to believe that the underslab vapor retarder is the problem at 0.0081. Have they considered drying out the slab?
As to topical systems there are plenty to choose from. My top two are Koester - http://www.kosterusa.com/us_en/foa-96-364/moisture+vapor+reduction+systems.html and Aquafin - http://www.aquafin.net/en/Topically_Applied_Vapor_Barriers-709-2-productgroup.html. |
Robert E. Woodburn, AIA, CSI, CCS, CCCA
Senior Member
Username: bob_woodburn
Post Number: 86
Registered: 11-2010
| | Posted on Friday, June 06, 2014 - 04:02 pm: | |
Thanks, Ken. Dex-O-Tex VaporControl Primer 100 has also been suggested. It has a perm rating of <0.16 dry, <0.80 wet. Yes, very different from 0.0081. |
spiper (Unregistered Guest)
Unregistered guest
| | Posted on Friday, June 06, 2014 - 04:51 pm: | |
What type of floor is going in the gym. Another option might be to utilize a vapor release sheet. Taraflex makes some products for situations like this.
If you must use a topical system we have always had good luck with Koester (vap 2000 I believe) and Ardex MC is not bad either. |
J. Peter Jordan
Senior Member
Username: jpjordan
Post Number: 741
Registered: 05-2004
| | Posted on Saturday, June 07, 2014 - 11:43 am: | |
I am not sure these products are vapor barriers, but they do reduce the moisture vapor transmission to levels that are acceptable to most flooring manufacturers (the rating is lbs/1000 sq. ft. / 24 hours, not perms). They are usually 2-component epoxy components costing between $1.50 to $5.00 per sq. ft. depending on what type of performance you need.
Koster and Ardex have products, but most manufacturers of resinous flooring systems will have one that they recommend for their systems.
Of course, if your Owner had any cajones, he would make the Contractor rip up the floor and put in the right stuff or refuse to pay for that portion of the work including the moisture mitigation membrane.
I have thought for the past several years that moisture problems in the floor may result more from excess water in the mix than from moisture in the soil. If this is the case, drying will help this situation (provided you have the time) and the vapor retarder will be sufficient. If the Contractor has permitted too much water in the mix, it reinforces the validity of my suggestion that this is the Contractor's problem, not the Owner or Architect, and he should be fixing it without increase in the contract sum or time. |
Robert E. Woodburn, AIA, CSI, CCS, CCCA
Senior Member
Username: bob_woodburn
Post Number: 87
Registered: 11-2010
| | Posted on Monday, June 09, 2014 - 11:05 am: | |
Thanks; we'll look into these. Cost data is helpful too. |
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