Can 2 layers of #30 asphalt felt replace my rainscreen?
We were planning to use Home Slicker Rain screen behind PVC NuCedar shingle siding. We have packed out the windows and already installed some of the 30# felt on the walls before we discovered that the Home Slicker is not going to work with the shingles. This is despite working in advance with the manufacturer and us doing mock up installations ahead of time.
We have to install the shingles on a firm surface and the manufacturer does not allow using furring strips underneath the nailing location only. About 30% of the 30# felt is already on the building and is integrated into the 1/4″ plywood we used to pack out the windows. That 1/4″ is also already covered with liquid flashing.
My question is, can we get some of the benefit we would have gotten from the Home Slicker product by adding another layer of 30# felt? It is not a completely smooth product in that it tends to pucker when it gets wet. Will the second layer act as a dimpled rainscreen and help us with protecting the sheathing? The PVC shingles are not vapor permeable and so our walls will be drying to the inside. We have plywood sheathing and plan to use BIBs dense pack insulation in the walls.