Protection Board below or above insul...

Log Out | Topics | Search Moderators | Register | Edit Profile

Author Message Anonymous   Posted on Tuesday, February 19, 2008 - 01:13 pm:    Can anyone summarize the times when protection board (IE, dens-deck) would be appropriate above a metal deck, but below the insulation and when it is appropriate above the insulation? John Bunzick, CCS, CCCA, LEED AP Senior Member Username: bunzick Post Number: 850 Registered: 03-2002 Posted on Tuesday, February 19, 2008 - 01:24 pm:    Below insulation when part of a fire-rated assembly. Above the insulation for physical durability, wind uplift, or exterior fire exposure. Not necessarily required just because one of these conditions exist--you need to look at the specific proposed assembly, manufacturers' data, and code. Richard Baxter, AIA, CSI Senior Member Username: rbaxter Post Number: 69 Registered: 12-2004 Posted on Tuesday, February 19, 2008 - 01:35 pm:    I’ve been told (by a Dens-deck rep) that you should use a cover board below PVC or TPO membranes where hail or excessive foot traffic may be a problem. David R. Combs, CSI, CCS, CCCA Senior Member Username: davidcombs Post Number: 263 Registered: 08-2004 Posted on Tuesday, February 19, 2008 - 01:50 pm:    Above the metal deck, and below the insulation, when required as a thermal barrier between the occupied space and the foam plastic insulation. Above the insulation for durability, as John states above. Indeed, it should be recognized that, depending on project requirements, some roof assemblies will have both. Don Harris CSI, CCS, CCCA, AIA Senior Member Username: don_harris Post Number: 174 Registered: 03-2003 Posted on Tuesday, February 19, 2008 - 02:09 pm:    Sometimes the Dens-Dek is required for proper adhesion of the roof membrane. Some membranes are not recommended to go directly on the felt facer of the polyiso. Wayne Yancey Senior Member Username: wayne_yancey Post Number: 6 Registered: 01-2008 Posted on Tuesday, February 19, 2008 - 02:48 pm:    I would not use the term "protection board" for either location. Substrate board or thermal barrier under insulation (5/8" or 1/2") and cover board (usually 1/4") over insulation. Both have a different purpose. In my experience, protection board (the term) is a product usually installed over hot fluid-applied waterproofing such as Hydrotech 6125. Wayne Anonymous   Posted on Tuesday, February 19, 2008 - 02:13 pm:    Thermal barrier no longer required for foam insulations (this has been true for years, but people still erroneously instruct otherwise. Check UL tests for foam insulations used in this condition and you will find that the thermal barrier requriement is no longer there). Over steel deck, below insualation, the proper term for this is Substrate Board. It is there to provide a substrate for the insulation if deck flutes are too far apart to support the insulation and/or as a substrate to support a vapor retarder. Over insulation and under membrane the correct term for this is Cover Board. Matter of choice in most cases except where required to achieve a fire classification rating (as is sometimes the case with wood framing/sheathing). MasterSpec has this all very neatly orgainzed in roofing assembly sections. Ronald L. Geren, AIA, CSI, CCS, CCCA, SCIP Senior Member Username: specman Post Number: 622 Registered: 03-2003 Posted on Tuesday, February 19, 2008 - 09:08 pm:    Where does it state that thermal barriers are no longer required? I'd check 2006 IBC Section 2603.4.1.5. The thermal barrier is not required: 1. If the insulation is separated by 1/2-inch plywood (0.47-inch, specifically) and all edges are supported by blocking, T&G, or other approved method; or, 2. Where foam plastics are part of a Class A, B, or C roof-covering assembly and the insulation has passed FM 4450 or UL 1256; or, 3. (From Section 2603.9) Where foam plastics have been approved based on large-scale tests per NFPA 286, FM 4880, UL 1040, or UL 1715. The tests must be related to the actual roof installation. Otherwise, it is required IAW Section 2603.4. It may be that most foam insulation doesn't require thermal barriers, but not all insulation is created equal; and some may not have been tested in a roofing application. Therefore, blanket statements, such as "Thermal barrier no longer required for foam insulations," could lead to problems if the insulation is not researched for compliance beforehand. (PS: I hate anonymous postings) Anonymous   Posted on Wednesday, February 20, 2008 - 01:00 pm:    If you can find a foam plastic insulation approved for use by a roofing membrane manufacturer that does not meet the requirements of one of the exceptions, please tell, and I will retract my statement. Thanks for listing the exceptions in the discussion thread. Anonymous   Posted on Wednesday, February 20, 2008 - 01:58 pm:    I have heard of stories from fire marshalls of hot melted insulation dripping onto firefighters from roof assemblies above their heads. It's a tough enough job for them already, we ought to be sure that we use the right types of insulation in the right applications and use a substrate board wherever it is needed. (A different anon, sorry) Anonymous   Posted on Wednesday, February 20, 2008 - 04:14 pm:    Yes, I have heard the same stories. It wasn't until I discovered that UL testing had been done to disprove these stories that I stopped perpetuating them. UL tests do not support the fantasy that firefighters are being harmed from dripping, melting foam insulation while attempting to extinguish building fires, and I have never seen ANY proof to the contrary. If I relied on stories as a basis for writing my specs, they would be a sorry lot indeed. Lynn Javoroski CSI CCS LEED™ AP SCIP Affiliate Senior Member Username: lynn_javoroski Post Number: 730 Registered: 07-2002 Posted on Thursday, February 21, 2008 - 08:51 am:    If you are requesting a full-system warranty from the roofing membrane manufacturer, the system that manufacturer recommends is the appropriate one, whether it includes protection boards, thermal barriers, or peanut butter. Dale Hurttgam, NCARB, AIA,LEED AP, CSI Senior Member Username: dwhurttgam Post Number: 31 Registered: 10-2005 Posted on Thursday, February 21, 2008 - 02:46 pm:    One of the common reasons for us to provide a substrate board is to form a base for a vapor barrier. Most of the buildings that we design are humidified and we typically provide a vapor barrier within the roof assembly on these projects. Anonymous   Posted on Friday, February 22, 2008 - 09:31 am:    Ronald L. Geren: Your "IAW" acronym/abbreviation sent me for a spin trying to figure out what code you were referring to. I realized it made sense when looking in a list of military abbreviations: "in accordance with." To those of us who are acronym-impaired, it could have been any of the following, except for context: International Association of Waterproofers Insulation and Waterproofing International Association of Wrestling International Alliance of Women Israel Association of Woodturners Illinois American Water Company Islam Awareness Week International Auto Workers Internet Access Worldwide In Another World David Axt, AIA, CCS, CSI Senior Member Username: david_axt Post Number: 987 Registered: 03-2002 Posted on Monday, February 25, 2008 - 05:00 pm:    Anon, You are wrong! Thermal barrier boards are all over the UL Fire Resistance Directory. The added advantage of those boards is that they provide a good base to laying down a vapor barrier, temporary roof and/or insulation. Phil Kabza Senior Member Username: phil_kabza Post Number: 304 Registered: 12-2002 Posted on Monday, February 25, 2008 - 08:50 pm:    As for relying on manufacturer warranty requirements in order to establish appropriate requirements for roofing systems: proceed with caution. Roofing manufacturers do not require a cover board over foam plastic insulation for installation of a single-ply membrane, even though the NRCA has recommended it for years. The reason is that the cover board protects from a failure mode that is not a warranted failure. Membrane puncture damage results from external causes rather than warranty-covered membrane material failure; the same is true of degradation of the unprotected insulation over time resulting from foot traffic. The roofing manufacturer has no incentive to require the installer to increase their cost by installing a cover board - they don't manufacture them. Installers continue to float a thin piece of plastic over some foam insulation and call it a roof system. They even give 30 year warranties, and contractors and owners continue to think that they're worth something. Go figure. Now: have the manufacturer and installer sign on to provide inspection and maintenance for a substantial period of time; select the team on the basis of evaluating long-term performance of their installed systems, based on a survey. Then let's talk. Anonymous   Posted on Tuesday, February 26, 2008 - 12:07 pm:    David, If the material is being used to support a vapor retarder, it is not a thermal barrier, but a Substrate Board. There is a difference.