Bay insulation

[robertglines1]

How much insulation would one put on bay roof /underneath plywood coach floor? is it cost effective? does it require 100% coverage? experiences and observations please.    Bob

[thomasinnv]

I would say more is always better, but not always practical.  The problem with insulatiing bay ceilings is that still leaves some un-insulated areas in the front and rear.  For those who's bus is already converted that would be the only way really though, and definately better than doing nothing.  A couple inches of spray in foam would be first choice in my opinion.  For the guy who has an empty shell, put down some insulation on the floor and build a new floor on top of it.  That would be my way anyway.  I didn't insulate my floor.  Had I to do it over again, I would probably put down some astro-foil insulation and then put the new floor over the top.  It's not much, but it's better than nothing.  I don't have a raised roof and I am 6'2" so I don't have a lot of room to add to the floor.  Just my way, you do it your's.

[Joe Camper]

I've never encountered that thru an entire bus.  The only place I have seen it is in the plumbing bay or around aqua-hot and webasto lines.

We have a tunnel up the middle below the floor runs front to back, make sure you insulate at the front and the rear there. Those tubes are mini wind tunnels going down the road. Shove some insulation in the ends of those tubes.

Under the drivers floor would be another great candidate for this but there is entirely too much up there to try there.

I found some electric throw rugs looking for an alternative to underfloor heat that I could not afford when I was installing our cockpit flooring. Still would like to try them haven't yet.

[robertglines1]

on last one I insulated bay doors and floor of bay. was thinking (it hurts) of insulating just ceilings instead? or both? Bob

[PP]

Hey Bob, We didn't do it ourselves, the PO did. But they sprayed the entire undersides of the bus with aprox. 4 inches of spray foam and then treated the foam with a black substance that looks like standard undercoating. It was applied under the driver's compartment, down the bulkhead, and clear to the rear drive axle. They didn't foam the fuel tank, but they undercoated it and on back to the engine compartment. There isn't any insulation between the interior floor and the bays. I should add that they filled the bay doors with foam also. We now have hardwood (lam) floors and have experienced a few frosty nights, but haven't noticed really cold floors except beneath the bed which is over the engine/trans with no insulation. We keep everything we own in the bays and haven't had any problems with anything ever freezing. Of course, since we fulltime in the bus, the living space is always maintained between 70 and 80 degrees which keeps the bays warm. I'm not sure what foam they used, but it's tough stuff. They even carved a path through it that leads the generator exhaust back to the rear drive tire with just a tin shroud to deflect exhaust heat away from the foam. Since this was originally a Marathon conv., I'm sure there are a lot more out there that were done this way. Hope this fuels your imagination to think outside the box (bus) Will

[Joe Camper]

PP other than the exhaust shield that is probably Marathon handywork all the spray foam under the bus and in the bay doors was sprayed on by Prevo.

On our XL the cockpit was terribly cold in winter and hot in summer. Here is a bunch of mistakes made at the factory that everyone with an XL can fix to improve.

First if you take the lower dash off you will see black 1 in foam glued to the backside of the front stainless. It will be curling back unstuck and cut terribly short of the spaces it's trying to insulate. I reinstalled newer bigger pieces and glued them in.

Next the pocket for the lower entrance door hinge is a opening to the compartment behind the front bumper. Is has to have a box built around it and it needs to be sealed up good or cold air will blow up from the bottom of the stairs. Drop your front bumper stick you head in so yo can see over there. There should be a wooden box built around that hindge, seal that up good.

Next we have a knob that controls a blend door, air recirculate or fresh air, well, when closed it leaks like a screen door on a sub. The intake is a opening on a downward facing lip above the front bumper, center. I sealed it up with duct tape  

Next the rubber boot that is attatched to the floor that wraps around the steering column will have dried out and cracked to bits leaving huge gaps.

Next the a/c lines coming up from the bottom of the inside of the dash have those small round lines coming thru big square holes.

These were the things I did that made some significant differences for our XL and I believe most are just the same.  

[robertglines1]

thanks Joe. have found some of those will ck out others. I have dash out now and all sheet metal off inside front. used spray foam on every thing that looked suspect. will take it further on your advice. might even add another inch of insulation in easy cover areas. Also as you mentioned I cut a large area out of floor at front just behind step exposed center utility trace and built a air dam there out of spray foam including PVC ducts (can easily dig it out if ever need to access any wires or hoses). I already had a hole at other end to repair fire damage   Bob