Floor Options - 2X2's or just Insulate and Plywood?

[o1marc]

Spray foam UNDER the bus......

How could you sacrifice the headroom??

My bus is spray foamed completely from underneath. Loosing 0” of headroom. Used full 3/4” subfloor t&g ply.

I see people doing all this mastic/foam board foam floor craziness but I’ve learned that millinials are completely programmed to you tube. Monkey see monkey do. Let’s all grow beards together!!

Post some pics, a bunch of us would like to see how it's done. I'm 5'8", when I consider cost versus ease of installation, rigid board is the obvious choice. Half the cost and install is much easier and less time consuming with the same results.

 

[Twigg-SKO]

Personally I'd be removing the chair rail and side panels on the inside of any conversion. If you don't then what you are losing in thermal bridging on the sidewalls will far offset any gains you get from using 2" XPS on the floor. You may as well use thinner foam that you can bend if you are going that route IMHO.

Please don't remove the chair rail.

You will notice that it is thicker metal, and welded to everything it touches. It is that way because it is the main structural member holding the entire body together.

It's not that hard to insulate both sides and the inner walls will not touch it.

 

[2martins]

My son just realized this afternoon that the emergency door area is ANOTHER unprotected edge for the insulation. Also, ours has a dip by the door. Did other people make that flat or do we need to keep it for some reason?

Please don't remove the chair rail.

You will notice that it is thicker metal, and welded to everything it touches. It is that way because it is the main structural member holding the entire body together.

It's not that hard to insulate both sides and the inner walls will not touch it.

 

[Twigg-SKO]

My son just realized this afternoon that the emergency door area is ANOTHER unprotected edge for the insulation. Also, ours has a dip by the door. Did other people make that flat or do we need to keep it for some reason?

The dip on mine is 5/8th inch, the thickness of the OEM ply that I left down but has a cut-out by the door.

1/2" of XPS filled it and I'll run a metal threshold strip over the exposed edge.

 

[2martins]

Our dip is like 3"!! Almost the width of the door and about 3" across. No idea why.

The dip on mine is 5/8th inch, the thickness of the OEM ply that I left down but has a cut-out by the door.

1/2" of XPS filled it and I'll run a metal threshold strip over the exposed edge.

 

[Brewerbob]

Spray foam UNDER the bus......

How could you sacrifice the headroom??

I'm raising the roof 18".

My bus is spray foamed completely from underneath. Loosing 0” of headroom. Used full 3/4” subfloor t&g ply.

Good luck working under your bus. Too many things in the way. Fuel tank, air tank, diff, etc. If you ever need to chase a wire, you're screwed.

I see people doing all this mastic/foam board foam floor craziness but I’ve learned that millinials are completely programmed to you tube. Monkey see monkey do. Let’s all grow beards together!!

Hope that wasn't directed at me. I'm an '80s kid gen Xer. I dunno if they are any more monkey see monkey do than any other generation but you're right, I just don't get the beards but then I never understood the mullet either (I never had one). Someday they are going to look back on the scruffy beards and say what the hell were we thinking?!

with the same results.

This part is a lie!! Spray foam will seal each and every hole. I have too many pin holes from rust to go chasing them with tape, pennies, etc. Putting down some rubber paint would probably work but I like the idea of spray foam for the floors, walls, and ceiling. Make that sucker as air tight and more importantly water tight as possible.

 

[Brewerbob]

Please don't remove the chair rail.

You will notice that it is thicker metal, and welded to everything it touches. It is that way because it is the main structural member holding the entire body together.

It's not that hard to insulate both sides and the inner walls will not touch it.

It would probably be ok to cut the chair rail off. Is his International the same as my Blue Bird? On mine, chair rail is thicker and attached like you say but the actual rail part that is in the way is only 1/2"~ 3/4" out. Sure it's a 90° bend and partly structural but not make or break I don't think. Take a cutting wheel and zip along the bend. Cut it two ribs wide on this side, ....

Wait, was going to say alternate but why? Cut the lip back far enough to slide a sheet in and then push it to the back of the bus. Then shove another until you have them all in. The wheel wells might be a problem but you'll still get 70% of the bus done with a single rib's width of lip missing. Weld it back on or bridge that rib with some new angle iron and it will be stronger than OEM.

Our dip is like 3"!! Almost the width of the door and about 3" across. No idea why.

So, the International is different there at the very least. My floor is flat expect for the wheel wells and the driver's seat. Wheels measure 9 1/2" high and the driver's seat is ~2" high.

How tall is your e-door? Mine MIGHT be 5 feet tall. 3" wouldn't be anywhere near enough for even HS kids to get thru without cracking their foreheads. And my bus was a HS bus.

 

[o1marc]

This part is a lie!! Spray foam will seal each and every hole. I have too many pin holes from rust to go chasing them with tape, pennies, etc. Putting down some rubber paint would probably work but I like the idea of spray foam for the floors, walls, and ceiling. Make that sucker as air tight and more importantly water tight as possible.

What part is a lie? Can you see every square inch of the floor, that can be seen from inside, under the bus? I seriously doubt it. So your under carriage spray job will be inferior at best. There may be holes in the floor on top of frame rails or other stuff mounted under the bus. It just seems like an awful amount of work to have the same result, adequate insulation inside the bus, just to save an inch or to inside.

 

[Brewerbob]

What part is a lie? Can you see every square inch of the floor, that can be seen from inside, under the bus? I seriously doubt it. So your under carriage spray job will be inferior at best. There may be holes in the floor on top of frame rails or other stuff mounted under the bus. It just seems like an awful amount of work to have the same result, adequate insulation inside the bus, just to save an inch or to inside.

I was going with foam board is as good as spray foam being a lie.

Spraying under the bus vs in the bus... I'd go with spraying inside the bus is superior (and my intention). Like I said the diff, fuel tank, air tank, etc is going to get in the way even if you don't care about spraying over wiring, fuel lines, and whatever else is under there.

I can see the entire floor and spray behind the chair rail a whole lot easier from the inside.

 

[o1marc]

I was going with foam board is as good as spray foam being a lie.

Spraying under the bus vs in the bus... I'd go with spraying inside the bus is superior (and my intention). Like I said the diff, fuel tank, air tank, etc is going to get in the way even if you don't care about spraying over wiring, fuel lines, and whatever else is under there.

I can see the entire floor and spray behind the chair rail a whole lot easier from the inside.

I understand. If cost were no object, my priority list would be to first spray foam the inside. 2nd would be rigid board inside before I'd chose to spray foam the underside. But that's just me. I hear the argument about spaces being left uninsulated and what a waste of time it is to do it at all if that's the way you want to do it. I don't follow this reasoning as some is better than none and if 90% is insulated you're going to be a whole lot warmer or cooler than without. With rigid board I know I can cover every square inch on the floor, not sure if spraying underneath will result in the same with bare spots all over. Again, I'm short so it's not an issue for me.

 

[2martins]

It would probably be ok to cut the chair rail off. Is his International the same as my Blue Bird? On mine, chair rail is thicker and attached like you say but the actual rail part that is in the way is only 1/2"~ 3/4" out. Sure it's a 90° bend and partly structural but not make or break I don't think. Take a cutting wheel and zip along the bend. Cut it two ribs wide on this side, ....

Wait, was going to say alternate but why? Cut the lip back far enough to slide a sheet in and then push it to the back of the bus. Then shove another until you have them all in. The wheel wells might be a problem but you'll still get 70% of the bus done with a single rib's width of lip missing. Weld it back on or bridge that rib with some new angle iron and it will be stronger than OEM.


So, the International is different there at the very least. My floor is flat expect for the wheel wells and the driver's seat. Wheels measure 9 1/2" high and the driver's seat is ~2" high.

How tall is your e-door? Mine MIGHT be 5 feet tall. 3" wouldn't be anywhere near enough for even HS kids to get thru without cracking their foreheads. And my bus was a HS bus.

I have smacked the heck out of my head on the Emergency Door several times already. It's ridiculously short but the 3" doesn't really help. And it's raised again at the edge anyway now that I think of it. Seems completely stupid.

 

[Brewerbob]

I understand. If cost were no object, my priority list would be to first spray foam the inside. 2nd would be rigid board inside before I'd chose to spray foam the underside. But that's just me. I hear the argument about spaces being left uninsulated and what a waste of time it is to do it at all if that's the way you want to do it. I don't follow this reasoning as some is better than none and if 90% is insulated you're going to be a whole lot warmer or cooler than without. With rigid board I know I can cover every square inch on the floor, not sure if spraying underneath will result in the same with bare spots all over. Again, I'm short so it's not an issue for me.

In the perfect world, I would spray both top and bottom. Spray the bottom with 1/2"~1 ... just to keep everything coated and from rusting. Then 2"~3" inside for the real insulation and to cover everything that was missed underneath. But the spray stuff ain't cheap and I don't want to cover any wires, lines, or bolts.

I have smacked the heck out of my head on the Emergency Door several times already. It's ridiculously short but the 3" doesn't really help. And it's raised again at the edge anyway now that I think of it. Seems completely stupid.

Wait what??? So with the e-door open there's a lip you have to step over? So, you survived the crash and the resulting fire only to break your neck tripping over a sill getting out of the bus. Tell me that isn't a lawsuit waiting to happen.