Box vents and torch down roof


I have a low pitch roof with attic space. The roof itself is either modified bitumen or torch down, either way it is some sort of rolled asphalt roofing with granular texture. I have four box vents, but really need a couple more. My question is; absent using a torch, what is the best method of installation? and what sort of sealant is best for this type of install?



What makes you think that you need more vents? Installing vents on a low slope job is not a very diy friendly job. Do you have any intake (soffit) vents? If not any vents you install will not work to their full extent anyway.


I have about 1600 SF of roof, there are four existing box vents, and soffit vents on the eaves, which extend out about two feet from the house. Doing some research it seems as if the attic is “undervented” if you will. I’m also planning to install a whole house fan to help with cooling our main floor in the summer and want to make sure I have enough venting for that as well. In total, my calculation indicates about 300 square inches of net free air, which I would need to increase to about 500 for the whole house fan.

Henceforth the desire to add more roof and soffit vents. I’m just wondering what the correct procedure is to install a couple box vents on this type of roof, and if roof cement is adequate, and if so, what type of roof cement.