High Roof Deck Coating

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Author Message Jerome J. Lazar, RA, CCS, CSI, SCIP Senior Member Username: lazarcitec Post Number: 1111 Registered: 05-2003 Posted on Tuesday, July 01, 2014 - 10:21 am:    Ive been asked for my educated opinion on two products, Kemper's Kemperol Liquid applied roofing and Siplast's Parapro the application is over a concrete substrate at an elevation of 57 stories, client is looking for at least a 15 year warranty and no flashings to maintain. I have no experience with either system, though I understand they are both top notch products. Hope some of my peers are better educated. Thanks to all for input. ken hercenberg Senior Member Username: khercenberg Post Number: 785 Registered: 12-2006 Posted on Tuesday, July 01, 2014 - 10:41 am:    Jerry, Kemper has a number of different liquid roof membranes including a PMMA (methyl methacrylate) similar to the Siplast Parapro product. Both have a variety of systems. Will this be applied directly to structural concrete or to lightweight insulating concrete? Considering your use, I have to presume that you're not using it in a PRMA (protected roof membrane assembly) which is the system I'd prefer to see this used in. PMMA has very limited elongation, something I'd consider to be critical in most roofing applications. If this is a high traffic roof, or if missile impact is a concern, PMMA may be a good alternative to low-end single-ply roofs. PMMA is not cheap. I'd lean towards higher end KEE, torch-applied mod bit, or Sarnafil PVC, whichever is your default in that area. I don't believe you'll get any better performance or service out of a PMMA in your application. I'd be concerned about the number of applicators in your area who have more than a couple of years of experience with PMMA vs. your other options. It's not a bad roof, it's just nothing special Jerome J. Lazar, RA, CCS, CSI, SCIP Senior Member Username: lazarcitec Post Number: 1112 Registered: 05-2003 Posted on Tuesday, July 01, 2014 - 10:47 am:    Ken, thanks for responding, the client is primarily concerned about limiting flashings; they specifically do not want flashing at slab edges. The roofing is over structural concrete, cost at this point is not an issue. ken hercenberg Senior Member Username: khercenberg Post Number: 786 Registered: 12-2006 Posted on Tuesday, July 01, 2014 - 10:56 am:    Not sure what is meant by limiting flashing. Every roof system has to be flashed somehow. Edge of roof details are the most important; field of roof rarely is the point of failure. How high is the parapet? The transition from horizontal to vertical will be critical. Will the walls be moving with the roof deck or independently? Is there a transition from the roof membrane to the wall/parapet weather barrier? Jerome J. Lazar, RA, CCS, CSI, SCIP Senior Member Username: lazarcitec Post Number: 1113 Registered: 05-2003 Posted on Tuesday, July 01, 2014 - 11:13 am:    This roof is just a flat slab (well it slopes to the drains), no parapet. They would like to have the roof system turn down the edge of the slab and stop without a visible flashing ken hercenberg Senior Member Username: khercenberg Post Number: 787 Registered: 12-2006 Posted on Tuesday, July 01, 2014 - 11:34 am:    So the roof deck 'counter flashes' the top of the walls and is left exposed on all 4 sides? If they want the 'roof membrane' to be a deck coating I'd probably lean more towards a polyurea instead of a PMMA and embed an aggregate for slip resistance. Either way, you'll definitely need the manufacturer to sign off. I presume you should at least be able to get a 10-year warranty if they're okay with the application. How will they flash the transition from roof deck to top of wall condition? Wayne Yancey Senior Member Username: wayne_yancey Post Number: 660 Registered: 01-2008 Posted on Tuesday, July 01, 2014 - 11:39 am:    Jerome, I have two projects that used Kemper products successfully. Wayne Jerome J. Lazar, RA, CCS, CSI, SCIP Senior Member Username: lazarcitec Post Number: 1114 Registered: 05-2003 Posted on Tuesday, July 01, 2014 - 12:47 pm:    The craziness of this job is that there is an Envelope Consultant and a local WP Consultant on the team, and my contractual role is not to select products, just write the specs, still when push comes to shove they always come back to the specwriter. ken hercenberg Senior Member Username: khercenberg Post Number: 789 Registered: 12-2006 Posted on Tuesday, July 01, 2014 - 01:30 pm:    But this way it's so easy to blame you and get free services from you to boot. What's not to like? Jerome J. Lazar, RA, CCS, CSI, SCIP Senior Member Username: lazarcitec Post Number: 1137 Registered: 05-2003 Posted on Wednesday, July 16, 2014 - 10:15 am:    Ken, you mentioned polyurea as an alternative product, can you offer the names of such products so I can do further research. Lynn Javoroski FCSI CCS LEEDŽ AP SCIP Affiliate Senior Member Username: lynn_javoroski Post Number: 1857 Registered: 07-2002 Posted on Wednesday, July 16, 2014 - 11:26 am:    Will they also need fall protection? If there's no parapet, how do you prevent someone from walking off? Jerome J. Lazar, RA, CCS, CSI, SCIP Senior Member Username: lazarcitec Post Number: 1138 Registered: 05-2003 Posted on Wednesday, July 16, 2014 - 11:40 am:    Its a decorative concrete element, not an accessible roof nor walkway. ken hercenberg Senior Member Username: khercenberg Post Number: 802 Registered: 12-2006 Posted on Wednesday, July 16, 2014 - 01:30 pm:    I've used Polycoat - http://www.polycoat.org/ with good results and DS Brown has a product called Deckguard that has been well thought of in transit projects for railroad bridges. Their product information and available technical data is horrendous but their product is apparently very good - http://www.dsbrown.com/Resources/Bridges/Deckguard/DeckGrdBrch.pdf Pacific Polymers has a polyurea deck coating but I have not used it: http://www.pacpoly.com/products/default.asp?Industry=Polyureas&Title=Polyureas&include=ed6500.html. I've had good success with other Pacific Polymers products in the past.