Wind-Resistant Roof: Eave-Edge Assembly
Damage from a fallen tree gives us an opportunity to see how well the wind-resistant eave-edge assembly is bonded together.
Builders typically don’t go back months or years later and dismantle homes to see how the assemblies we build are holding up. It’s not till a disaster strikes that the details get tested. This month a large tree fell across the roof on the house where we photographed the article “9 Upgrades to Windproof Your Roof” for the March 2019 issue. To make repairs, we had to cut away all the roof sheathing covering the hip rafter and jacks back to the second common rafter. Removing over 24 ft of eave edge, we got a chance to see how well the sandwich we layered up last June to hold the first course of shingles tight to the roof deck worked.
The drip edge was nailed down at 4 in. oc with every third nail driven into the roof rafters. The ice barrier membrane bonded to the top 1 1/2 in. and a 12 in. layer of Protecto Wrap Roof Edge Seal double-sided bonding/flashing membrane was stuck over the exposed flashing and ice barrier. The starter row if shingles was set flush with the bottom of the drip edge and adhered to the Roof Edge Seal. Nails driven 2 in. up from the edge mechanically held the starters in place. Finally the first course of shingles was placed flush with the drip edge and sealed to the starter strip via the self-seal strip.
I tried to peel the drip edge off the roof sheathing when removing the sheathing panels from the broken jack rafters but it wouldn’t budge. We ended up cutting through the drip edge and shingles to get the panels off the roof. I picked at the layers of flashing and roofing with a flat bar to see how tight everything was bonded. The adhesive bond between the drip edge /Roof Edge Seal / and starter strip was so strong the starter shingle shredded apart exposing the fiberglass base mat. And the self-seal strips between the starter and first course of shingles bonded just as well leading to shingle shredding when I tried to separate them.
The roof has only been in place for 9 months so it’s hard to know if the adhesive bonds will be as strong 35- 40 years from now when the roof is ready for replacement again. But hopefully it will stand up to the hurricanes and gales that our area is prone to from time to time.
