25C-071 ContegoPaintSpecificationsLetter_050515
May 5, 2015 Memo
TO: Whom It May Concern
FM: Contego International, Inc. RE: Contego Fire Barrier For ASTM E-84 and ASTM E-119 rating on Plaster and Wood Doors.
The following is a summary specific to your project where you will be treating legacy solid core wood doors for a Class A (ASTM-E84/UL-723) rating as well as a 1 hour rating under ASTM E119/UL-263 as used in your project. You also need to
enhance the fire rating of legacy plaster walls. This Engineering Memorandum sets forth our recommendations and assists in the development of an analysis of our data to support code approval for your application. This is important because Contego, as the manufacturer of the product, has expansive insight into the performance of our coatings on various
substrates. The materials used in your assemblies meet or exceed the fire endurance of any of the materials we have tested.
APPLICATIONS ON WOOD
• Our ASTM E-84 (UL 723) data on Douglas Fir with only one coat (10 mils dft) shows zero flame spread and limited
smoke production over the duration of the test. When compared to the same test on highly flammable spray polyurethane foam, which was extended to 25 minutes, the substrate was fully protected and flame spread and smoke production flatlined shortly after the initiation of the test. This indicates that such a test would and could have
continued indefinitely.
• Also, our latest UL-723 from Underwriters Laboratories shows a zero flame spread and zero smoke production overall. UL engineers indicated they have never seen this level of performance from an intumescent on wood. Our most recent test extended to 30 minutes shows a 0x5 Class A rating.
• Our NFPA 286 room burn also indicates long-term survivability on a wood substrate with zero contribution to a room
fire. Our combustibility in that test approximates concrete.
• Our UBC 26.3 shows excellent thermal resistance on OSB with the cold side temperature never exceeding an average of 1900F until eventually declining after 11 minutes and continuing to decline throughout the balance of the test period. Results on your materials would logically exceed this kind of performance since your substrate(s) are
several times thicker than the OSB and plywood we tested.
• Our UBC-26.2 thermal data illustrated long-term survivability considering the obvious limitation on thermal transfer on OSB, which is, again, lighter and more vulnerable than the materials you are using. Keep in mind that these tests were focused on thermal transfer. At no point was the wood substrate ignited or even charred. We have not yet
been able to generate burn through conditions for substrates as thin as ½”, even when made of flammable substrates such as OSB.
Specifically Applicable Data (Protection of gypsum sheathing and wall assemblies)
• Our U-338 assembly test (ASTM-E119/UL263/UBC-7.1/NFPA251/ANSI A2.1) conducted at SwRI’s laboratory in San
Antonio shows 1:25 on .500 regular ½” GWB. Since this is a 30 minute assembly, our result shows a 55 minute enhancement. Burn-through did not occur until 1:39:55, but we will use the 1:25:15 time since thermal transfer reached the allowable limit at that point.
• The section done in plaster already has an even better fire resistance rating. Plaster performs better because it doesn’t have the paper fascia that is the vulnerability of typical gypsum wallboard.
Generally Applicable Data
• Review the toxicology and adhesion data on our web site.
• Data from our test at Southwest Research Institute shows that the use of an exterior grade acrylic enamel, which increases fire resistance and thermal transfer by an additional 25% – 32%.
• Also, review the information on our web site on the many advantages of dimensional and manufactured wood with
Contego versus FR wood products.
• Our adhesion data, using both the ASTM ribbon-cut and cross cut methodologies should exceptional adhesion and the inability to mechanically separate our coating from primed steel. Our ASTM D-4531 data shows better than twice the adhesion of any other product, up to four times the adhesion of others.
• Our vapor barrier test shows better efficiency than plate glass.
The laboratories used in our testing program are all independent, certified, audited, and internationally accredited. Please refer to our web site to download copies of our complete test results. Our data exists in the form of UL and ASTM approved test protocols. Data can be found at www.ContegoInternational.com.
Accordingly, I recommend that you apply a dry film total thickness of 20 mils on all surfaces of the wood and 15 mils on all surfaces of drywall/plaster. While this is overkill, it covers your needs and should resolve any doubts about the ability of your assembly to meet your requirement. In the event of fire, our coating swells up as much as 6 to 8 inches and will seal
off any gaps that may exist. In the case of the doors, paint all exposed surfaces and the trim around the door. While you could remove the trim and
spray our coating into the framing elements of the door, that is optional, but not necessary. Painting the wall surface 6” around the trim would be advised.
Given these performance characteristics, Contego International is certainly willing to certify the performance of our coating on your assembly for not less than 60 minutes in accordance with ASTM-E119 / UL-263 time/temperature curves.
Contego has other advantages in that it is not toxic nor it is a carcinogenic material. While the test data supports this recommendation, feel free to experiment with the sample sent to you to see for yourself using the most demanding test format you can imagine. What you will see is that materials treated with Contego are noncombustible at or exceeding
standards applied to any other material. Hopefully, this answers your questions, but feel free to call if we can be of further service.
Sincerely yours,
Tony Scott
Executive Vice President, Strategic Development TS/fg