Re: 1976 Winnebago D21 Brave complete rennovation - Saggy AC Fix!

[rude-a-bego]

There are dozens of post out there about roofs sagging where the AC unit is mounted in a Winnebago.  Upon further review, I have found out why.  Talk about design flaw!
In my D21, there is a 3/4" piece of plywood on the front and back of the unit sandwiched in the ceiling.  However, it is 48" X 8", centered on the roof... IT DOES NOT TOUCH THE SIDES!  There is absolutely no support from side to side.  There are main metal beams in the back and front of the coach but none in the middle!

I know Winnebago was cheap but...  really?!?!?

Note:  The red marks in the picture indicate the ends of the plywood.
Note:  Roof sag = 1.25"

[rude-a-bego]

So here is how I fixed it...

1.  Braced up the roof and added 1/2" to create a little bit of a bow.
2.  Surgically cut a 1.5" channel into the insulation / ceiling right next to the plywood AC support.  I cut away right down to the last layer of paneling.  Note: where the wood was rotted, I cleaned right down to the aluminum.
3.  I used a piece of u-channel and fit it extra tight to support my slight bow and "construction adhesived the ba-jezzas" out the channel and the u-channel.
4.  I screwed in the ends into the top place of the side walls.
5.  Lather, rinse and repeat on the other side of the AC unit.

NOTE:  if you try this at home, be aware that there is some wiring that will need to be re-routed.

[cosmic]

I did the same thing as you, but thicker steel. I used the galvanized post stuff for parking, and other kinds of signs. used pl premium to glue wood in there so now I had a place to staple my new ceiling panels . I also went double thicker on the angle on the sides then used some nice self taping screws. Also I went over the outside walls.

[cosmic]

pic. I can jump on it now. with the ac. lol.

[ibdilbert01]

Talk about design flaw!

When working on mine with my Pop, I say things like that all the time.   His reply is... "It lasted 43 years didn't it?!"     :)rotflmao

[Lefty]

My '76 Chieftain came with additional metal supports in front of and behind the roof A/C. They were made of 1 1/2" X 3" rectangular tubing, and were even wrapped with vinyl woodgrain to blend in. They were bolted to the angle iron at the base of the wall, and also had bolts about 2/3 up the wall. And ran across like roll bars.  These were in addition to the other two supports in the coach. Perhaps there were an option? Or perhaps unique to just the D27MI commercial chassis? Or even, maybe created and added by a really inventive P.O... who knows. But the roof on mine was like walking on a concrete deck.

[rude-a-bego]

Nice!
I see I went with the "diet coke" version.  I have the back side prepped.  However, after seeing your post, I am now considering using the thicker steel that you used vice the thinner one I used.  I was also contemplating putting in new plywood but the majority of my roof is intact. 
Thanks for the posts!

[rude-a-bego]

Touche to ibdilbert01's POP.... touche

[Froggy1936]

The manufacturers attitude is that it only has to outlast the warranty ! They are in the business of selling new . Not surviving on parts sales for 50 yrs . Where as we would like to make them bulletproof for a lifetime !  Frank