Concrete floor prep for sheet floorin...

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Author Message Russ Hinkle, AIA, CDT, LEED AP Senior Member Username: rhinkle Post Number: 95 Registered: 02-2006 Posted on Tuesday, February 07, 2012 - 10:05 am:    Any one have any experience using Concure Admixture in concrete floor slabs (both on grade and raised)? The contractor is proposing this as an alternative to the floor prep we have specified. Russ Hinkle ken hercenberg Senior Member Username: khercenberg Post Number: 157 Registered: 12-2006 Posted on Tuesday, February 07, 2012 - 12:00 pm:    Russ, a few suggestions to consider: 1. Get certification in writing from the finished flooring manufacturers that they will accept the floor. 2. Conduct testing anyway, even if the admix manufacturer insists it's not necessary. 3. Do not eliminate your underslab vapor retarder. 4. Check to see what their warranty says about cracks in the concrete. This is usually an exclusion, yet concrete cracks as it dries and shrinks. 5. What is the remedy in case of failure? Can you apply a more traditional 'fix' such as Koester after this has been added? I would find out first. 6. Who is responsible if it fails? Typically by accepting a substitution design professionals are as liable as if they specified the product. Will the GC take responsbility, including cost to fix, if this doesn't work? Sorry I can't say anything about past experiences. I know many people who are not comfortable with either the admixtures or the 'spray-and-pray' processes available. J. Peter Jordan (Unregistered Guest) Unregistered guest Posted on Tuesday, February 07, 2012 - 11:14 am:    What are you trying to do? frustrated spec writer (Unregistered Guest) Unregistered guest Posted on Tuesday, February 07, 2012 - 11:51 am:    Russ, I recently spent many hours on this topic myself. At first I was really hopeful that these types of products were a perfect solution to the problem in specific situations. After researching I have concluded that while good in concept, I cannot take the chance. The warranty claims are compelling, but the bottom line is that these products are not proven through any independent testing to be vapor retarders meeting the requirement of what I specify for sheet vapor retarders (ASTM E 1745). I asked the manufacturers of these products for this testing and what I got were tests that are not an apples to apples comparison, and proved nothing about ability to retard vapor through the slab. I did get one test from a manufacturer that showed it passed ASTM E 96 with a perm rating lower than that required in ASTM E 1745, but when I tried to find contact information about the third party testing outfit that conducted the test, I discovered it does not exist! No telephone, no address, nothing on the internet. This issue came to a head for me when one of the flooring manufactures provided a written position paper declaring all bets were off if any silicate-based product was used on the slab or in the slab - which is what all of these products are. I looked at Moxie, Sinak VC5, and Concure - none of them could provide me with any testing showing vapor through the slab. Near the end of my research period, I started hearing a lot of off-the-record claims that these companies products fail all the time - and that they do not make good on warranty claims when flooring does fail. I was not able to verify any of this, but it made me uneasy to hear these reports - from more than one source. So, I have decided to stick with the tried and true methods - sheet vapor retarders placed directly beneath the slab on grade, topical film-forming epoxy-based vapor retarders, and dehumidification (where needed). Hope this helps. Russ Hinkle, AIA, CDT, LEED AP Senior Member Username: rhinkle Post Number: 96 Registered: 02-2006 Posted on Tuesday, February 07, 2012 - 12:43 pm:    Contractor has proposed using this product in lieu of the Koester product we specified (for a hospital project). Of course the information they are passing on to me reads like good marketing material with promises of milk and honey if only . . . I am skeptical, but need good arguments to put to the team that is desperate for VE items. Russ Hinkle Russ Hinkle, AIA, CDT, LEED AP Senior Member Username: rhinkle Post Number: 97 Registered: 02-2006 Posted on Tuesday, February 07, 2012 - 01:30 pm:    frustrated spec writer - why the anonymity? Russ Hinkle ken hercenberg Senior Member Username: khercenberg Post Number: 159 Registered: 12-2006 Posted on Friday, February 10, 2012 - 12:26 pm:    I've asked around and been warned off the manufacturer you asked about but I have no direct experience; just passing on what I've heard. Two manufacturers of admixtures who were identified at a recent CSI meeting as possibly acceptable were SPG and Barrier 1 but I would use them with caution as well. Apparently there are now flooring manufacturers who will not warrant installations over concrete with these types of admixtures. I'd start with your flooring manufacturer and work back from there. Mark Gilligan SE, Senior Member Username: mark_gilligan Post Number: 457 Registered: 10-2007 Posted on Friday, February 10, 2012 - 03:45 pm:    This can be a nasty issue to coordinate. Concret admixtures are specified in the cast-in-place concrete spec section. The structural engineer knows from nothing about flooring products. The decision to use these admixtures is typically made by the project architect who may not be thinking about flooring products. Besides products such as Xypex what other types of admixtures are of concern.