Roof leak

[rcjokibbe]

I noticed a soft spot on the roof last weekend while cleaning and started investigating it this weekend. I'm pretty sure the leak is coming from the antenna housing, which had a loose screw and several rusted screws. I have attached pictures showing where the soft spot is. The red circle is the loose screw. Not only was the screw loose, but it seems the sealant was not done properly because the other screws were rusted and one had a rusty head. I have not called Grand Design or the dealer, but I'm guessing they won't do anything about it.

I'm worried about cutting the mushy wood out, because there could be duct or wiring underneath. I'm thinking about leaving it, applying kilz, and then laying the membrane back and tape it back up. I do expect to sell it, but that's probably three to five years out. Not sure if a small soft spot that's been treated is of concern to a buyer of a used RV.

Any advice for cutting the wood out without damaging the stuff unknown underneath? Any advice on going with plan A and to leave it and treat it?

Not cool antenna installer person!

 

[Hoopy Frood]

Why wouldn't you contact Grand Design? The worst thing they can do is say No, but if you don't ask, you won't know. Certainly couldn't hurt.

 

[TimtheToolMan]

I noticed a soft spot on the roof last weekend while cleaning and started investigating it this weekend. I'm pretty sure the leak is coming from the antenna housing, which had a loose screw and several rusted screws. I have attached pictures showing where the soft spot is. The red circle is the loose screw. Not only was the screw loose, but it seems the sealant was not done properly because the other screws were rusted and one had a rusty head. I have not called Grand Design or the dealer, but I'm guessing they won't do anything about it.

I'm worried about cutting the mushy wood out, because there could be duct or wiring underneath. I'm thinking about leaving it, applying kilz, and then laying the membrane back and tape it back up. I do expect to sell it, but that's probably three to five years out. Not sure if a small soft spot that's been treated is of concern to a buyer of a used RV.

Any advice for cutting the wood out without damaging the stuff unknown underneath? Any advice on going with plan A and to leave it and treat it?

Not cool antenna installer person!

I would guess that wires in the area likely are a bit below the wood, due to gravity, but I would be careful as you are about possible damage.

What about cutting with a multi tool and possibly trying to not quite go all the way through? Then pull up to break off the soft wood.

I would be tempted to leave the soft OSB and just add a piece of aluminum sheet, at least .06" thick (likely thicker). If roofing is not stuck to the OSB too much cut the aluminum long one direction and slide it under, especially toward some solid OSB. Add some adhesive sealant around perimeter, like maybe polyurethane, to bond AL to OSB. The goal is to try to make it strong enough to stand on. The roof material will have a bump where AL is positioned.

Possibly use a scope through the hole to see if insulation is compromised. A small amount of wet insulation would not be a significant concern to me.

Let us know how it goes. Others will be dealing with this at some point.

 

[Riverbug]

Rather than cut it out, you might want to consider epoxy restoration or similar. Scroll down in the link and read through the article and see if that helps. It doesn't appear to be completely rotted and if you can dry it out, one of these solutions may help. Obviously, this is geared toward marine/boats but many of the solutions work great for RV. For example, using an adhesive caulking (such as 3M 4000UV) rather than self leveling crud will provide a much better and long term seal.

https://www.jamestowndistributors.com/product/Epoxy-and-Adhesives/Wood-Rot-Repair-and-Restoration

 

[rcjokibbe]

I took Hoopy's advice and sent an email to GD this morning. I'll follow up with them on Monday and see what they say.

I realized after sending my post that I can reach in from the neighboring fan opening and feel for wires or obstruction. I checked this morning and it seemed clear and maybe cutting the OSB won't be so scary. I do have a multi tool and a jig saw to make the cut. The insulation felt dry under the damp OSB.

I also like the idea of adding structure to the existing OSB with aluminum. At this point I have accepted the roof won't look original and ok with a bump.

New but related question, I have seen videos of RV'ers using the eternabond over their sealant and that seems like a good option to avoid an issue like I did. How would I remove the eternabond if I need to replace a fan or skylight? Does it peal off with the help of a heat gun and plastic pry tool?

 

[Riverbug]

No question, Eternabond works pretty great.

If you clean the wood well and scuff it a bit, you can apply Eternabond directly to the wood. I've done this where I cut the roof membrane around the vent and self leveling caulk, exposing an inch or two of wood around the opening. Then, use adhesive caulking under the edge of the roof membrane to seal it down (it usually comes up pretty easy if it's even glued down at all). Then you can apply Eternabond overlapping the roof membrane and down over the exposed edge of the opening. Next, place your vent (adhesive caulk under the flange for good measure), screw it down, and run Eternabond over the top. Now you won't have to worry about resealing that fixture until you have to replace it.

Edit: Answering the question about applying Eternabond over the existing caulk...you can. However, it doesn't adhere well to the caulking so you need to either buy a wide enough roll to ensure you can cover the caulked area and reach a good flat surface, or use two strips of Eternabond overlapping to cover past the caulk on each side.

 

[rcjokibbe]

GD replied and said sorry but out of warranty. Sure, whatever, but hopefully their person installing the sealant and screws get's retrained and better.

I used the multi-tool to cut out the rotted piece. Great idea by Tim to use that tool, because I did find the air duct a couple inches below and the tool was easy to keep away from it. I glued and screwed in cleats to the perimeter of the existing OSB and then screwed in a new piece. The 1/2" OSB from Menards is a bit thicker than the existing OSB so it is raised up. I plan to put tape along the seem before putting the roof TPO down so it doesn't rub. So far it's ok, but not great.

Thanks Chad for the info on how to apply eternabond. I think I understand what you described. I'm going to use that method when reinstalling the vent. If I were do something similar when reinstalling the antenna housing, does this sound correct: Clean the TPO, put down tape on the TPO where the housing flange will rest (covering the old screw holes), add adhesive caulk to flange, screw in, place additional tape over the flange and screws so it reaches the tape and TPO roof. No sealant necessary?

 

[Jsuders04]

Sorry, but - what trailer and year was this for?

 

[Riverbug]

Clean the TPO, put down tape on the TPO where the housing flange will rest (covering the old screw holes), add adhesive caulk to flange, screw in, place additional tape over the flange and screws so it reaches the tape and TPO roof. No sealant necessary?

Perhaps one point of clarification...The top layer of Eternabond just needs to cover over the flange/screws but is fine if it just lays over the bottom layer of Eternabond. The top layer does not need to reach the TPO. Eternabond sticks to Eternabond very well so no need to make sure it reaches the TPO if you already covered that with the first layer.

It is also an option to just use Eternabond on the bottom layer, then adhesive caulk to cover the screws, etc. as you normally would. Either are very reliable long term, but the two layer Eternabond method over vents is pretty darn foolproof.

p.s. Your fix is looking good!

 

[TimtheToolMan]

Nice fix and you knocked it out pretty quickly! I like the frame that you added to support the OSB. I did not think about the replacement OSB being thicker than the original.