Question for professionals about mansard roof

Hello, I recently replaced shingles on mansard roof that is approx 4 feet high around the entire home. The contractor used Owens Corning duration shingles. I was watching them nail the shingles down and they were not using any roofing cement during the installation. They were using four to six nails per shingle tab. I asked about roofing cement and was told that it will be used afterwards to secure the shingles, once the shingles warm up in the sun for few days and flatten on the roof. I read somewhere that the roofing cement should be applied to the shingles prior to nailing them on steep roof. In addition, there was recommendation to use 6 nails per shingle tab. Any comments and suggestions from the professionals will be appreciated. Thank you in advance for any advice.

Yeah O.C. dose require 6 nails and dabs of roofing cement on mansards. However I would bet 75% of roofing companies aren’t aware of that requirement. Also on a mansard it is EXTREMLY important to nail on the double thick area of the shingle. While it is always important but on a mansard there is the possibility of the shingle sliding apart.


load your phone app (“pitch guage”) over a 20 pitch requires caulk (mansard)
lot of installers like to go back and hand seal shingles to reduce the mess

Thank you, IslandRoofing. You reply is very informative and greatly appreciated.

Thank you, kevroofer for your reply. i just hope that adding the cement post nailing is not going to cause additional problems of broken shingles and so on

It shouldn’t, that’s how I would do it as well. Keeps the hands from getting to messy while laying the shingles.

1 Like