The roof replacement at Concord Baptist Church was a challenge on many levels. The roof had hail damage, and it was paid for by the insurance company. We started tearing off the roof on January 4th, 2016. During the tear off, we noticed that the sheathing was not solid wood but rather a mineral board. After pulling the architectural plans, we found out why. This building was built as a Fire Class 2 rated structure. Essentially, this means that the building itself had to be constructed out of non-combustible material. Steel, concrete, brick, and mineral board is the construction of this building. This created one big issue for our company. Code and the manufacturer, both, required a nailable surface (wood only). However, since the building was built as a Class 2, we had to stay within those parameters.
To solve the problem, we had lengthy discussions with Loadmaster, who supplied the original mineral board, and Owens Corning, the shingle manufacturer. We agreed that a new layer of mineral board needed to be installed to create a new nailing surface, and a specialty fastener ( Do All Loc Nail) was to be used. These nails have a head similar to a roofing nail, but they have two prongs that come straight down as well as jagged teeth on the sides. Once the nail is driven into the mineral board, it flares out and locks in.
Once Owens Corning and LoadMaster agreed on the installation, we went to the code office and got approval. The insurance company was notified of the difference in scope, and a supplemental check was issued.
We got back started on the roof in the middle of February. We worked in conjunction with the LoadMaster installers and a gutter company to complete the work.
We removed each section, 6 total, and added an additional layer of 1/2" LoadMaster mineral board. The mineral needed to be installed differently than the first 2 layers due to the increased wind ratings. All the seams on the mineral board were taped. We installed Rex Synthetic underlayment and high temp ice and water shield. We also installed new Owens Corning Duration Estate Grey shingles. We replaced all the lead boots, 5 box cents, 24 gauge step and counter flashing, and custom fabricated drip edge. The project took 6 weeks to complete.
This project was rather complicated. However, by following the installation guidelines with the manufacturers we were able to put on a roof that will last the next 40+ years.