Above Sheathing Ventilation with Radiant Barrier Roof Assemblies
Sharkskin Ventilated Roof Mat® w/Sharkskin Ultra Radiant® create both above sheathing ventilation (ASV) and Sharkskin Ultra Radiant® reflects radiant heat and creates a cooler attic, which reduces cooling costs. See contractor testimonial below.
Installed in 2014
This job is a just completed re-roof and is a vacation rental on the beach in Laie (northern stretch of the northeast shoreline of Oahu). It is a simple structure with wood beams running horizontally and 2×8 T&G planks (just under 1-1/2 inch thick) running vertically (eave to ridge). The 2×8 is exposed inside and is finished with a clear stain so there is no opportunity to add insulation below the roof deck. The owner said that the heat introduced to the interior of the house from the ceiling was a big problem and he needed to find a way to ensure that it would be cooler inside the house than it was outside.
With the very light structure, we had to keep the roof load (weight of the roof) to a minimum and I thought of using your Sharkskin Ultra Radiant over your polypropylene ventilating mat, over a “dry-in” layer of Sharkskin Ultra as our underlayment. The total weight of the underlayment is less than ¼ pound per square foot.
We then installed the aluminum Country Manor Shake, which weighs less than ½ pound per square foot and which has a cool, infrared reflecting, Kynar 500 paint coating. The hI-R finish keeps the aluminum panels about 50 degrees cooler than conventional paints. We used 1-1/2 inch long stainless steel ring shanked nails to give us about an inch of penetration into (but not through) the roof deck.
We installed our molded “Free-Floating” EPS FoamGuard inserts in each aluminum shake roofing panel. The FoamGuard, besides being a good insulator on its own, creates an additional thermal break by leaving small gap between the aluminum roof panel and the EPS.
The installed roof system is tight to the roof deck, solid under foot and very easy to walk on without denting the panels. We had no trouble with any of the penetrations (skylights, hood vents and plumbing pipe vents) The owner came up on the roof during installation and is very happy with the results. He now wants us to re-roof several other properties he owns on Oahu.
Thanks for introducing this great product.
Submitted by: Fred Rehm, Owner, Aluminum Shake Roofing,
Note: Sharkskin Ventilated Roof Mat™ to be installed with only Sharkskin Roof Underlayments