Under floor insulation?

[colin57]

After finding a rotten floor ,pulled out the guilty section to find some kind of expandable foam on the underside of the plywood & in parts it is sandwiched between the frame & floor.After doing my frame repairs,was wandering if I should put some kind of spacer between the frame maybe lay a bead of new good stuff immediately before I put the new section of plywood down.Trying to do all this without pulling the belly pan,if I do have to pull it then I can spray good stuff from underneath after floor is down,or maybe I dont have to bother as this is not a pededstrian area.

[marzboy]

Those door way outriggers look pretty thrashed. I had to completely cut out and rebuild that whole section on mine. Pretty sure you are gonna have to remove the belly pan. Have you checked the other openings? Hatches doors windows? Water travels down the walls and will rust out the frame. I wouldn't use spray foam either, it will disintegrate. Try Prodex or glue foam block insulation under the new patched in sub floor.

[Lance M]

Colin57,
Welcome! I'm guessing this is your '67 GT right? You really must remove the belly pan to properly repair the frame and outriggers. People will say you don't have to remove the belly pan. I disagree. You'll be better off biting the bullet now. You must have the trailer level across the frame and floor. I would not recommend spray foam. Here is how I attached rigid polyiso foam to the underside of my '72 Ambassador. Good luck!

[Wabbiteer]

You've been framed. No quick or easy fixes. My sincere condolences.

[colin57]

thanks guys,this my 69 overlander which I bought on e-bay after many conversations & viewing pictures prior to making the bid and having being told the everthing was sound.Had the coach shipped from ohio to california,upon arrival I immediately found a spongy spot right inside the door& was able to grab handfulls of plywood & then peeled everything back to find the extent of corrosion you now see.
I think your right i,ll have to remove the belly pan ,that way I can see how the rest of the frame is,& also install whateve foam product I decide to use.I have fabricated some steel to reinforce the frame & have the outriggers ready to go which I would be able install from the top as I plan to weld the outriggers onto the new metal which in turn will be welded & bolted to the frame .
As I write my order of cleacos & pliers have arrrived so the belly pan re-attachment will be a lot easier,so now I,m less daunted by the task that lies ahead.Will keep you posted with some pics.Ian

[marzboy]

Yep site unseen on Ebay has claimed many victims. But take heart nothing is imposable. Just more cash and time!

[Wabbiteer]

^^ I is one.

Keep each task man-sized -- I have a real problem with related areas intruding into the work flow so a half-day task grinds to a halt... something accomplished, finished every time you attend the work area and it will be done before you know it.

[colin57]

Removed all the rusted out step & outriggers yesterday & fabricated a piece of c channel to go acroos the door as that was pretty bad.I took WSmith's suggestion & bought a inspection camera & after probing around the rest of the frame , it looks like I lucked out,everthing looks pretty good. I will have to take the banana wraps off the front to get access to a couple of welds & to put some insulation/spacer material between frame & floor.It's going to be fun working with all the different levels on the frame for this patch job.I can see why they alternated the heights of the crossmembers to accomodate the joins in plywood sheets,but it looks like they welded the front crossmenber too high on the c channel as I will have to put some kind of shim material on top of the c channel so the plwood can lay flat if that makes sense.Today I will prepare the frame for welding & apply some of Eastwood's rust product,s.Well it felt good to get started on this ,It's only been 2 yrs since I found all the decay.Ian

[Aerowood]

Originally Posted by colin57

I can see why they alternated the heights of the crossmembers to accomodate the joins in plywood sheets,but it looks like they welded the front crossmenber too high on the c channel as I will have to put some kind of shim material on top of the c channel so the plwood can lay flat if that makes sense.

I had the same problem on a cross member, one side 1/4" higher then the other. What I did was taper the splice with a router. I ripped a splice piece wider then I needed and then screwed a 1X2 vertically on each side with one end displaced a 1/4" higher then the other. I then mounted a plate under the router that was double the splice in width and ran it up and down the whole length until I had a tapered splice. It didn't take very long to do.

[colin57]

pretty clever,unfortunately i,m trying not to tear up any more flooringas i,ve taken the rotten ply back to the join where the splice is still intact.,but I,m relieved to hear i,m not the only one with this problem.I think i,ll have to make some kind of tapered shim,kinda like a door shim to feather the gap to the end of the outriggers.
It wouldnt be fun unless we had these litlle hurdles to overcome ,right!

[Wsmith]

Evidently my main frame was welded up a little high on one side in the front. The OSB had been planed down about 3/16" deep and back about an inch inside the skin. So looks like you did it the factory way.