Self -adhesive (peel ‘n stick) roofing underlayments are a considerable improvement over felt paper for secondary water protection. When shingles or other roof coverings fail in severe weather, the right underlayment can shield the home from significant water damage.
So why did some homeowners here in Florida pay for a peel ‘n stick product only to have it blow away during a hurricane just like their neighbor’s felt underlayment? According to a building scientist involved in evaluation of failed residential construction, the reason was simple……the installation instructions were not followed.
The peel ‘n stick manufacturer will normally specify a primer to cover the waxy top coating present on most OSB roof decking. The waxy coating can inhibit adhesion. For example, the following sentence is from the installation instructions for Grace Ice and Water Shield’s self-adhesive underlayment: “Prime wood composition and gypsum sheathing with Perm-A-BarrierWB Primer if adhesion is found to be marginal (refer to Technical Letter 12, Use on Oriented Strand Board (OSB) Roof Sheathing).”
Are your roofing installers following the manufacturer’s instructions?