How do I repair rotted walls?

[lotsofspareparts]

O.K., Me and my wife just bought our first RV. 1979 Minnie Winnie 20RG. I noticed that there was a soft spot under the forward bunk and  there is an abundant amount of rot and I would like some advice on how to fix it.

Thanks

[ibdilbert01]

For sure use the search option, plenty of post on how to fix rot.

Keep you head up, I doubt yours looks this bad...


After a few trips to Lowes and 1.5 billion tubes of Mr Nails, it now looks like this.


Anything can be fixed!  And with these old rigs, its not so bad, as they were pretty much all put together by hand using common tools anyhow.  As for rotten walls, is it this bad yet?



Transformation as follows....

[Oz]

Jared, if you "freaked out" at what you saw, you can see from these photos that it's no big shocker to man of us.  And, if your rot is confined to a small area, it's not anywhere near as extensive a repair as what Tim had to do.  This is all part of vintage RV ownership.  Some can handle it, some can't.  Depends on the rig they bought and the mettle of the person buying it and.... resources.  Which we have in abundance.  As Tim said, message search.  The walls are a thermopanel construction.  That's in the messages too.  Another, very good resource is the Eyebrow Winnebago Coach Service Manual, for this, and many other issues you are likely to encounter.

Now, if Tim would be so kind as to give a brief, yet detailed, description of how he fixed a portion of the walls, this would be a good topic to add it to.  Especially with the gory, explcit horror photos he just posted!

[lotsofspareparts]

Oh Wow!!, I don't feel quite so bad anymore!!

[lotsofspareparts]

My problem (after further stabbings with a phillips screwdriver), is confined to the panel directly above the bunk, the left (drivers) side wall from the front to the head, and the entire bunk support?? (the part that hangs out over the windshield).

[Oz]

The wall construction is known as "Thermopanel".  It is a sandwich of the exterior, extruded aluminum skin, styrofoam, and plywood, glued together, with panelling on the interior side.  This "sandwich" is described and depicted in the coach manual, as well as the repair process.

Basically, the exterior trim must be removed, the skin carefuly separated from the foam with a scraper, and the rotted secion of wood removed.  New plywood and any affected frame wood put in, styrofoam glued on top of it, then the skin glued to the styrofoam.  The trim is then caulked and reinstalled.

I'll leave it to othes to fill in the plywood and styrofoam thickness and recommended glues etc.

[ibdilbert01]

So as the the PhÃ¥rÃ¥oh says, the walls are thermopanel construction.   There is a good mix of plywood in areas that need reinforced, you'll find the styrofoam will be in good shape, and the wood is the only part that is bad.   

Their is a bit of a layer in different areas I assume they did for added strength.     Some areas are solid styrofoam, some are a layer of styrofoam and plywood, and some are two layers of plywood.  All plywood in mine was 3/4".

So in the example below, you'll see two rotted layers of wood.



Where the bunk mounts are, there is extra plywood in the walls.  Also where the West coast mirrors mount, they doubled the wood.  (as the example above)  The areas where the Dinette tables mount too, there is extra plywood as well.

What I found out was the paneling came off pretty easy.  Once I pulled the windows out, I was able to grab the paneling with my fingers and pull it off.   What was left was rotted wood and near perfect styrofoam.   

I took the old wood off as carefully as I could, and used it as a template to jig out new wood (3/4" plywood).   I used Mr Nails to glue it to the siding, and trust me when I say this, get it where you want it, because when it dries, you'll bend the aluminum trying to straighten it out.    I had some gaps between the new wood and the styrofoam, I used window styrofoam in a can to fill all the voids, then went back with a knife and cut it flush so the paneling would go over top smoothly.    Again I used more Mr Nails to glue the paneling, and used a brad gun to temporary hold the paneling till the glue dried.  To get the new paneling between the dash and to replace some wood, I actually pulled the fenders away from the body, then re-attached them. 




Also what I found was at floor height in the wall is a 2x4.   The 2x4 fastens to some angle iron also running at floor height.   Its my assumption that this is the main support for the walls.   Also I found 2x4s about fender height in the very front, maybe 1.5ft long, the dash sides get screwed to it. 

Now your talking about a different area, above the bunk.   But it should be the same kind of construction.   here is the area above my bunk that had a bit of rot.



Now I actually copied another members repair, Handyman who replaced his entire roof.  But if you just have some rot up in the front, I don't see why you couldn't tear out the bad wood, and replace it with new wood.    It should just be standard styrofoam and standard plywood, both of which you can get at Lowes or Home Depot cheap.   And BTW, on mine, the entire eyebrow  was and  is styrofoam, no wood except the paneling.  So if thats where your rot is, you might get by with replacing just the white paneling.

[ibdilbert01]

My idea was to use sheets of 3/4in closed cell foam with 2 sheets of 1708 fiberglass on each side to replace the ThermoPanel.

I like that idea!  Actually I like that idea a lot!

[lotsofspareparts]

I did too until I priced it with the boss, 20 per sq ft my cost.

[ibdilbert01]

Thats pretty pricey.   Is this the kind of product your talking about?

http://www.fiberglasssite.com/servlet/the-69/Biaxial-Mat-1708-5/Detail

In the past I've order from Fiber Glast with good results, but I'm not in the trade to know where the deals are.
http://www.fibreglast.com

[lotsofspareparts]

Similar, but not the same. The 1708 we use is stiched at a 90 degree angle. The price I quoted was for a complete panel with myself performing the labor of layup and bagging.

[lotsofspareparts]

I think I will just go with 3/4in foam with 1/8in door skin on both sides for the wall and ceiling, I plan on using a sheet of 1in marine grade plywood for the bunk. It would be nice to go with the fiberglass but I know that once I start, I will not be able to stop.

[oilmaninpowell]

Knowing what lurks behind the walls may be a big help for those who are repairing a year or model for the first time. Here are some pics of what I have found. First a late (?) 70's Chief.

The third pic may be hard to make out but there is a big triangle of steel horizontally above the front window

[oilmaninpowell]

A few more.

The interior steel frame. There are plastic covers that snap over the steel.

Foam floor construction. Top, wood, foam and wood on bottom.

Roof construction. Aluminum up top, wood, foam and lastly wood with vinyl(?) covering on the ceiling.

Lastly there was wood at the bottom of the rear corner too.

[oilmaninpowell]

Inside a 72' Brave. Drivers inside front and rear.

[intofire1]

Thanks great pictures.

[Piraterik]

Oh Wonderful OZ,

Why is there no photos to this reply on repairing Rotted walls?  On the 1st Reply by iderbert.

[Oz]

Either he moved or removed the photos from their location, or the source host was changed or the account expired and not updated, causing a broken link.

[DRMousseau]

WoW!!! After seein' these pics, I don't feel quite so scared anymore!!!

The PO put a new rubber roof on the D20 not too long ago, and replaced ceiling panel. But walking on roof seems unnerving! The rear third of coach is quit solid, square and level. But the front 2/3s seems hollow, weak between supports, and has water collecting pockets. It was obvious that the AC had been removed(probably leaked bad), roofed over, and damaged ceiling replaced in a VERY poor manner. No leaks with new roof,... and it's better than a tarp, only because it doesn't flap in the wind!!!

Thursday, I replaced the old ceiling vent/fan in bathroom(?), and found NOTHING in the ceiling space beside it!!! No insulating core, no framing or support around the vent! Jus kinda "floating" on the aluminum roof, with the new rubber concealing everything outside, and a cut ceiling panel CAULKED around the edges to hold it up on the inside!!! UGH!

I made some quick and dirty repairs myself, while setting in the new vent/fan. But some serious work will need to be done before winter!

[Oz]

I totally agree!  I'm no carpenter but seeing how others have done it, including those who have and knew nothing more about it than I, I'd feel confident that I could pull it off successfully because they all took the time to share the experiences!