Community Forums

zogthegreat · 08-24-2016, 05:14 PM

Hi everyone!

I hope everyone is having a great summer without any breakdowns!

I have a 2004 Damon Challenger 348W with a EPDM roof. I went on the roof today to do a general checkup/cleaning when I noticed that the roof rubber has bulged up from the rear of the coach to the rear A/C unit, about 4' in length and from side to side. I removed one of the "roof rack" brackets and cut the rubber underneath and found that the wood is rotted out. The last time I did a good inspection was last April before I left Florida.

I haven't found where the roof is leaking yet, but it is obvious that I need to do some kind of repair work to the roof.

I know that the best would be to have the entire roof removed, the damaged area repaired and then have the roof recoated, but I don't have that kind of money!

So far I have come up with two possible plans:

Plan A - Carefully cut the damaged section of roof rubber out, cutting it back until about 2" of good wood. Cut out the damaged section of wood, replace it with a new piece of wood and then use polyester resin to reattach/reseal the repair section. Then recoat the roof with something like this to insure a good seal:

Dicor White Rubber Roof Acrylic Coating, Gallon - Dicor RP-CRC-1 - Roof Maintenance & Repair - Camping World

Plan B - Carefully cut the damaged section of roof rubber out, cutting it back until about 2" of good wood. Mix polyester resin and pour it directly onto the damaged wood. put the EPDM material directly onto the repair section and let everything cure and harden. Seal around the edges with some sealant, (something like this: Advanced RV EPDM Roof Sealant - Geocel 56801 - Roof Maintenance & Repair - Camping World), then once again recoat the roof with the Dicor roof sealant.

I'm sure that there is something wrong with both plans, as they both seem to simple! (Sorry, after a year of full-timing, I have found that it is always more complicated than it seems with these bleeping things!).

Anyone have any thoughts of suggestions?

Thanks

zog

BFlinn181 · 08-24-2016, 09:58 PM

Trying to glue EDPM roofing with polyester resin is not a good idea. Replace the rotted wood, making sure the roof supports under the plywood decking isn't damaged by the rot. Any cross members that show rot damage, but not replaced, can be treated with Git-Rot, a watered down epoxy that will soak into the wood and prevent further rot spread. Lay new exterior plywood and fasten to the support structure. The plywood should be sanded to ensure it won't damage the EDPM sheet. The EDPM should be glued to the plywood using a recommended contact cement, either solvent based or latex based. It is applied to the plywood and the EDPM sheet, then the EDPM sheet is rolled across to plywood. You usually put the contact cement on 1/2 the area and EDPM sheet, let dry and then roll the sheet on that half, then pull back the other side and glue those two surfaces together. Where the new meets the old roofing, you can overlap and use the contact cement or add Eternabond tape on the seams.

Polyester resin is NOT recommended and won't be a proper adhesive for the roofing.

zogthegreat · 08-26-2016, 04:48 PM

Hi BFlinn181,

Thanks for the advice! It seems simple enough, I guess I will see!

I have a question about the Git-Rot.

Quote:

Originally Posted by BFlinn181

Trying to glue EDPM roofing with polyester resin is not a good idea. Replace the rotted wood, making sure the roof supports under the plywood decking isn't damaged by the rot. Any cross members that show rot damage, but not replaced, can be treated with Git-Rot

From what I have been reading about it, (mostly on boating forums), it doesn't seem to be any more effective than polyester resin:

Q&A Letters

Have you used it before yourself?

Also, how much contact cement do you think I will need for a 4' x 6' area?

One of the things that I am thinking is since the damage seems to start at the very back of my rig, to loosen the EPDM from back and roll it to the A/C without cutting it, (if possible). Is this OK or should I just cut out the entire section?

Thanks!

zog

BFlinn181 · 08-26-2016, 05:00 PM

My Dad and I both used Git-Rot on our cruiser in the '60's and it did as advertised. Drilling many small hole close together gives the epoxy places to infiltrate the wood fibers. It's a bit thinner than regular polyester resin. I also used it on a wood boat in the '80's on some structural wood I didn't want to replace. Again, lots of drilled holes allowed the epoxy to soak the wood and harden it.

When you remove the plywood decking, carefully inspect the wood structure under it. (Maybe you'll be lucky and it will all be steel or aluminum) Any discolored wood has been exposed to rot fungus and should either be removed or treated to prevent spread of the rot.

You might be lucky in rolling the membrane back, but if it's too rough or lots of adhesive on the underside, it might be better to replace rather than re-glue it. It might be stapled in under the fiberglass end cap, be careful removing it.

The contact cement should have coverage information on the can, I can't really tell you.

Gordon Dewald · 08-26-2016, 05:47 PM

I replaced the EPDM and roof sheeting on our 5er for about 2,000. Did all of the work myself. Had a similar issue and decided when I had part of the roof off it was easier to do the whole thing than patch it.

I was not in a hurry and had it inside so it took a month to complete. Really happy with the result. Our leak was through the air conditioner.

zogthegreat · 08-26-2016, 05:55 PM

Hi Gordon,

Quote:

Originally Posted by Gordon Dewald

I replaced the EPDM and roof sheeting on our 5er for about 2,000. Did all of the work myself.

Ouch! Here I was thinking that was how much it would cost to have a professional do the job!

Quote:

Originally Posted by Gordon Dewald

Our leak was through the air conditioner.

I'm thinking that that is where my leak is coming from, however, there doesn't seem to be any damage after the A/C, so I'm not sure.

I guess I will find out once I start taking everything apart!

Gordon Dewald · 08-27-2016, 08:34 AM

Quote:

Originally Posted by zogthegreat

Hi Gordon,

Ouch! Here I was thinking that was how much it would cost to have a professional do the job!

I'm thinking that that is where my leak is coming from, however, there doesn't seem to be any damage after the A/C, so I'm not sure.

I guess I will find out once I start taking everything apart!

We were quoted 15,000 for the work at the RV dealership we purchased the trailer at.

The EPDM was 800, 200 for glue and self leveling sealant. I opted for plywood instead of OSB for the sheeting and went with 5/8 instead of 1/2". All stainless screws. It was cheaper to buy a 50' roll of 60 mill EPDM than a custom 43' piece.

zogthegreat · 08-31-2016, 11:22 AM

Quote:

Originally Posted by Gordon Dewald

The EPDM was 800, 200 for glue and self leveling sealant. I opted for plywood instead of OSB for the sheeting and went with 5/8 instead of 1/2". All stainless screws. It was cheaper to buy a 50' roll of 60 mill EPDM than a custom 43' piece.

Do you have any pictures from when you did the repair work? Also, what type of self leveling sealant did you use?

Thanks

zog

powderman · 08-31-2016, 11:39 AM

I suggest going to a roofing supply shop to buy the material. I bought .065 EDPM at$.65 a square ft. It came as 10' wide or $6.50 per running ft. So a 50' roll would be $325. That price was by the foot so probably less or a whole roll. So in reality the material is cheap. The labor costs, not so much.

Gordon Dewald · 09-01-2016, 06:30 PM

Quote:

Originally Posted by powderman

I suggest going to a roofing supply shop to buy the material. I bought .065 EDPM at$.65 a square ft. It came as 10' wide or $6.50 per running ft. So a 50' roll would be $325. That price was by the foot so probably less or a whole roll. So in reality the material is cheap. The labor costs, not so much.

Wish I would have seen this post before I bought the EPDM I did.

BFlinn181 · 09-01-2016, 06:38 PM

Quote:

Originally Posted by powderman

I suggest going to a roofing supply shop to buy the material. I bought .065 EDPM at$.65 a square ft. It came as 10' wide or $6.50 per running ft. So a 50' roll would be $325. That price was by the foot so probably less or a whole roll. So in reality the material is cheap. The labor costs, not so much.

Quote:

Originally Posted by Gordon Dewald

Wish I would have seen this post before I bought the EPDM I did.

EDPM roofing is the same for a flat roof as an RV roof, using similar thickness of material. Growing up on a boat, I quickly learned if it had the word 'marine' on it, it cost twice as much. Same is true of things labeled 'RV', you pay a premium for the intended use, not the actual quality of the material.