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gaucho10's avatar
gaucho10
Explorer
Sep 24, 2014

New roof on my 24 ft. Wildernes

Hello everyone. This is my first post and hope someone can help me. I am actually working backwards here since I have already installed part of my roof but now I am asking the questions....So here goes...

I had roof damage so I removed the old, thin rubber liner. I then removed all the rotted 1/8" luan and all the insulation.

I then installed all new insulation and I laminated (2) 1/4" layers of plywood. I screwed the plywood directly to the roof ribs/rafters. Now I have a strong roof that I can actually walk on. I am not concerned with the extra weight in this case.

I have purchased a kit of 60 mill white on black EPDM that I will install as soon as it arrives, hopefully this weekend.

As I was removing the old rubber roof I noticed that the luan joints were covered with plastic sheetrock tape. I also noticed that the roof edges had what appeared to be duct tape to protect the old liner.

Now for my questions:

1. Should I install the tape on all areas where the screws are located, namely over the rafters? Or would it be ok to just tape the joints of the plywood. Rafters are approximately every 12", plywood joints every 48".

2. Did I secure the plywood with too many screws? I placed screws approximately every 10" on center and around 6" along the sides.

3. Will the extra screws affect the strength of the roof since the trailer WILL FLEX during travel?

4. Should I countersink all the screws and use a filler or just lay the glue and liner? At present the screws are flush with the surface.
  • westend, I will check on "organic filler". The only type of filler I know of is HD/Lowes wood filler which might be "oil base" which I understand is a no-no with EPDM.

    Weldon, I originally planned on using duct tape only around the perimeter of the roof and the sheetrock plastic tape on the joints. I removed all of the decking so the whole roof is new plywood and all level. The original 1/8" luan went under the front aluminum and was flush on the back. It has now been installed the same, only 3/8" higher (thicker). I don't see any problems with the extra 3/8" affecting my "plywood-aluminum-EPDM" installation. I have feathered the edges around the perimeter so there are no sharp edges of plywood but I still plan on using duct tape as extra protection.
  • I would use duct tape on seams and screw heads. Your luan should be the same thickness as the old where it meets the ends. Did your old epdm go under the front and back ends? If yes then the thickness of luan needs to be the same in order to get the new epdm under the ends.
  • The tape is installed so the EPDM will not be grabbed by a screw head or uneven seam when installing. If you're confident that all screw heads are countersunk, all seam edges are even, and your adhesive will hold the membrane in place, you don't have to tape anything.

    If I was doing it, I'd use filler on the seams and screw locations. A small canister of organic filler is less than $5 and time involved on a 24' x 8' roof is less than 1/2 hour. Troweling the filler on will discover any screw heads protruding above the surface.

    Your fastener schedule sounds right on.

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