Author Topic: Wall Construction - Dry Rot in Slide Out  (Read 3879 times)

Mark Parker

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Wall Construction - Dry Rot in Slide Out
« on: August 06, 2018, 10:11:41 PM »
1999 Beaver Contessa (SMC) Naples 40' with 1 slide.

We are the 3rd owners of our Beaver and we love it.  We have been doing thousands of dollars of upgrades.  In the process of redecorating the slide out today I discovered some dry rot.  Arrgh.

My questions are:
1)  How is the wall constructed?  From the inside I can tell there is a luan panel over extruded foam between vertical steel square beams.  How far up do the square beams go?  Is it a complete frame supporting the top of the slide out?

2)  There are 4 screws at the front edge that go through a piece of metal and into the panel (and presumably what is beyond).  What happens if I remove these screws while repairing the panel?

Observations:
The dry rot does not extend below the window.  I am not 100% sure of the source of the water infiltration, BUT upon close examination of the outside, there is a metal piece of edge trim at the front of the slide out that is held on by pop rivets.  Most of the pop rivets are no longer doing their job and there is some separation occurring.  I suspect this is the entry point.  The other possibility is the awning attachment point at the top front corner, but I don't see anything obvious.  When I sight down the exterior I can detect a slight ripple in the problem area (almost like delamanation)...but is so slight that I had never noticed it before (say 1/64").

Proposed Plan of action:
I want to remove the screws and cut the bad interior panel back to the second (or third) square tube support and replace it with a new one.  Then replace the screws.  I really don't want to have to remove the window and hope that I can slide the new piece under the front and lower frame where required. 

Then put new pop rivets in the exterior leading edge.

It doesn't appear that the rot extends to the small area in the overhead cabinet...I am hoping that I don't have to drop the cabinet too. 


Steve Huber Co-Admin

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Re: Wall Construction - Dry Rot in Slide Out
« Reply #1 on: August 07, 2018, 02:50:15 AM »
Mark,
I'm pretty sure the aluminum struts run to the top of the slide.  The pop rivets and awning attach are both prime candidates for leaks. Consider using Lexel to coat any rivets you don't replace. I'd also put a dab of Lexel on each rivet hole before installing new ones. After you get the panel removed you may want to wet down the outside to see if you can spot the entrance point. Many times it takes wind to blow the water into the gap so don't be surprised if you don't see any, but it's worth a try. I'd make the new panel removable if possible in case you didn't get the leak sealed.
Steve
Steve
2015-          07 Contessa Bayshore C9,  400 hp
2013-2015: 00 Marquis Tourmaline, C12, 425 hp
2005-2013: 01 Contessa Naples, 3126B, 330 hp

Mark Parker

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Re: Wall Construction - Dry Rot in Slide Out
« Reply #2 on: August 07, 2018, 10:57:11 PM »
Thanks Steve.

I started removing the panel.

The square tubing is steel (not aluminum) and the tube nearest the end doesn't run straight up to the top...it only runs up to the tube under the window, BUT there is a tube that runs up the side of the window a few inches away, so the effect is pretty much the same.  There is also a square tube above the window that runs horizontally, so I am not too worried about any support issues while doing the repair.

I still don't know what will happen if I take out the 4 screws (circled in yellow) on the leading edge.

I plan on using 5mm underlayment as a replacement panel glued to the foam.

Is there any material between the foam and the fiberglass exterior wall?  How is the glass bonded to the wall panel?


Steve Huber Co-Admin

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Re: Wall Construction - Dry Rot in Slide Out
« Reply #3 on: August 08, 2018, 02:17:46 AM »
Mark,
I think the fiberglass is bonded with an adhesive of some sort but not sure what it is. Looks to me like the 4 screws are there to anchor the panel to the outer wall. A call to BCS or a body works service provider might give you more insight. You might want to check out the Service Providers list for one in your area. It's in the Private Members Only board.
Steve
Steve
2015-          07 Contessa Bayshore C9,  400 hp
2013-2015: 00 Marquis Tourmaline, C12, 425 hp
2005-2013: 01 Contessa Naples, 3126B, 330 hp

Mark Parker

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Re: Wall Construction - Dry Rot in Slide Out
« Reply #4 on: August 08, 2018, 04:54:40 PM »
thanks again Steve.  Looks like you had virtually the same coach as ours for 8 years.   :)

Steve Huber Co-Admin

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Re: Wall Construction - Dry Rot in Slide Out
« Reply #5 on: August 08, 2018, 10:41:05 PM »
Mark,
Just got reminded that if you coat the new 5mm underlayment with several coats of polyurethane (oil base minwax is good), if water does intrude again it should not cause it to rot anytime soon. (Thx, Ed)!
Steve
Steve
2015-          07 Contessa Bayshore C9,  400 hp
2013-2015: 00 Marquis Tourmaline, C12, 425 hp
2005-2013: 01 Contessa Naples, 3126B, 330 hp

Mark Parker

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Re: Wall Construction - Dry Rot in Slide Out
« Reply #6 on: August 08, 2018, 11:08:25 PM »
great point.  I wouldn't have thought of that.  I finished getting the old luan panel off the styro, and cut the new 5mm panel to fit.  It is slightly thicker than the luan panel it is replacing, so some bevels, etc were required.  Fortunately the seams will be hidden by the window box, and the sofa (or entertainment center if we swap sides in the future. 

Turns out that the exterior wall is of the same construction....foam inner core then luan panel glued on top, the the fiberglass bonded to the luan panel..Unfortunately that panel has dry rot too.  No clue yet as to what I'll have to do there.


Steve Huber Co-Admin

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Re: Wall Construction - Dry Rot in Slide Out
« Reply #7 on: August 09, 2018, 01:15:30 AM »
Mark,
If you don't see a lot of "waviness" looking at the fiberglass from outside the coach you may want to leave as is. Although I've never dealt with it, it seems that one would need a method of "pressing" the fiberglass to the luan or vice versa to  get a good seal and reduce the waviness/wrinkling in the outer skin.
Steve
Steve
2015-          07 Contessa Bayshore C9,  400 hp
2013-2015: 00 Marquis Tourmaline, C12, 425 hp
2005-2013: 01 Contessa Naples, 3126B, 330 hp

Darell T Hostland

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Re: Wall Construction - Dry Rot in Slide Out
« Reply #8 on: August 09, 2018, 02:08:10 PM »
My wife and I repaired a similar issue on our 1994 Patriot. We clamped 1 inch plywood on the outside against the fiberglass with 2x4's. We removed all the dry rot from the inside and old damaged Luan. We dribbled Gorilla glue down the wall between the fiberglass and the Luan on the fiberglass. Gorilla glue needs moisture to cure so don't worry about the wall being wet between the fiberglass and luan. You can replace the foam insulation and new wall panels on the inside in the same way. The fiberglass outside wall has no bubbles or waves on it and the paint was not damaged it is better then new. Also check the factory caulking at the top of the wall where roof meets the wall. Our rv had about 3 feet above drivers window with no factory caulking and about 2 feet above the door and side window.It turned out so good that we changed all the rug on the walls to new paneling.I posted pictures on a thread that had the same problems as this. Take your time and plan all the steps and have all tools and construction materials needed for the job. It is well worth the effort. It took us about 2 weeks to do all new paneling on both sides in the living area. My wife removed all the old flooring and made a paper template of the floor. She put in new flooring all in 1 piece in the kitchen and living areas as well as on the steps.

Mark Parker

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Re: Wall Construction - Dry Rot in Slide Out
« Reply #9 on: August 09, 2018, 07:08:43 PM »
great feedback.  Thanks.  I hadn't thought of using the moisture to my advantage (w/ Gorilla Glue).

Reading your posts on the thread: "Beaver Patriot drivers side window leak" made me go to the cockpit and take a close look.  AAAAaaarrrrgggh.  I have dry rot there too.  Sigh.  :o

Once I finish the interior slide out repair and painting, the new Pergo laminate (Sand Dune Oak) goes in.  The next project scheduled after that was a rebuild of the instrument panel/center console.  I guess I'll strip down the wall and do that repair first instead.

Mike Gineris

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Re: Wall Construction - Dry Rot in Slide Out
« Reply #10 on: November 27, 2018, 12:13:30 AM »
I also have a 1999 Contessa Naples with dry rot found around the window just aft of the door.  Have to tear apart and rebuild the inside.  I just found this post.  I noticed the upper gutter and thought it may be the culprit. 

Doug Allman

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Re: Wall Construction - Dry Rot in Slide Out
« Reply #11 on: November 27, 2018, 12:27:06 PM »
This comment has nothing to do about the dry rot itself as I think all the info on that has been passed on will work very well but as you finish the interior walls you may want to put a covering (wall paper) on.
When we did that in our Marquis we first used 3M spray glue over some of the old paper on the luan and also over the luan that had no wall paper on. Wasn't long before the wall paper was coming loose from the wall.
What did work for installing the wall paper covering was using the Border glue that is intended for going over a wall covering which is essentially a non porous sealed surface. You can get it in a small tub from Home Depot or Lowes. We brushed it on the wall and also on back of the paper and it worked extremely well and did not let paper come loose.

Darell T Hostland

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Re: Wall Construction - Dry Rot in Slide Out
« Reply #12 on: November 27, 2018, 12:52:30 PM »
Any paint used inside the rv should be a good exterior paint due to the extreme temperature changes inside the rv. The flooring has to be rated for the hot and cold temperatures as well. Use a good  thin plywood used to build boat hulls to minimize the expansion and contraction of the walls. We had to make new spacers around the windows as the plywood we used was a bit thicker than the old plywood. You can use screws on the inside plywood and fill the holes but it is better to use the gorilla glue and clamp the wood to the frame. The gorilla glue will have a bit of expansion and contraction and will move with the wood not fight the movement. If you use gorilla glue on the new plywood it will have to be damp for the gorilla glue to cure properly. You can use a paint roller and roll on water to the glue side. Don't use to much glue as it expands a small amount. The metal framing will have to be clean and damp as well. Use sandpaper to clean and ruff up the metal framing and the gorilla glue will stick to any type of metal. This was the first time we used gorilla glue and do not work for them or sell it.