Should Holes Be Cut In Camper Roof Before Or After Installing Roof Membrane?

Updated 10/20/2025 | Published 10/15/2025

Question:

I had gotten the alpha systems roof membrane kit. I am getting ready to install it soon. The lauan had some damages so i replaced the damaged areas and had redone and covered the roof with thin plywood. My question is how i do the holes for the vents and skylights ect...? Do i go ahead and cut the holes for them before i lay the mebrane or do i run the membrane and when everything dries do i cut those holes with the plywood and membrane as one? Thank you

asked by: David E

Expert Reply:

Hello David, good question. In my experience, it will be best to cut the holes for the vents before you lay down the membrane. That way you can cut away the membrane using a razor knife and get a good clean cut. If you tried to cut the roof and the membrane at the same time, the saw might tear up the membrane.

expert reply by: Jesse M