Inspecting Roof-Deck Substrates Ensures Successful Installations
A successful roof installation starts with ensuring specified products from the original manufacturer arrive unopened on site, dry and remain covered by tarps and stored on pallets so they do not get wet. Inspectors must observe the installation of the specified on-site materials at the beginning of each site visit. They should mark materials that do not meet the specifications and are not approved as a substitute by the architect or engineer and have them removed from the site.
Before the roofing contractor begins applying roofing materials, the inspector and roofing foreman should check the deck substrate for deteriorated decking scheduled for replacement— if specified for re-use— as well as loose debris or small objects not removed during tear-off or installation of new decking material. Inspectors also should check concrete decks for dryness by using a small amount of hot bitumen applied to the deck surface.
The inspector then should check for frothing or bubbling bitumen, which indicates moisture is present. If frothing or bubbling does not occur, the inspector should try to peel the bitumen off of the deck. If the bitumen peels off easily with no resistance, the concrete deck is too wet, and installers must allow it to dry.