Hi!

I had a bitumen roof installed recently on my roof with a slight slope. The roofer initially quoted us to have composition 30 yr shingles installed, plywood (since there was none installed under the prior roof), sheathing and ridge vent. When the City came to do the roof inspection they told them that we have to go with a lighter roof because of the dry wall that was installed on the ceiling. They said that the roof was not structured to carry that much weight. The roofer decided to go with a bitumen roof since it does not require having plywood underneath it. He told us that this new roof would be more expensive since the material is more costly, but he will do it at the original quoted price since he knew that we were on a tight budget.

The original quote was for $5150. My question is, why did the bitumen roof cost more when there was a lot less work that needed to be performed? There was no ridge vent installed, no plywood/sheathing purchased, no labor to install ridge vent and plywood. There were also only 3 roofers that installed the bitumen product vs 5-7 people that originally were here to install the shingle roof. Please let me know if my assumption is correct that the roof should have been less expensive with the Bitumen product install.

Thank you for your help.