Floor insulation - How to add after the fact...

[richard5933]

While running a bunch of new wiring over the past few weeks, I discovered that the only thing between our passenger compartment and the basement bays is a 1" thick piece of marine-grade plywood covered with Linoleum (or possibly painted cork). There is no insulation other than the carpet pad and carpeting.

My first thought is that it would be good to add some insulation, but then comes the problem of how. There are many (very many) wiring bundles and plumbing parts that protrude through the floor, which would make insulating from the bottom difficult. On first evaluation it seems that the foam would have to be cut into so many pieces that to install that it would be of limited use (and would really make the bus look a mess).

The inside is packed tight with furniture, all of which is permanently mounted making it near impossible to remove without causing serious damage. That makes insulating from the inside also difficult.  If things were gutted I could easily add insulation by gluing foam board to the floor. We're not going to gut the bus - no budget for that and no will to do it.

Then I looked again and realized that the exposed floor is actually only a small percentage of the interior area. The aisle is only about 20" wide running the length of the bus. The rest of the floor is covered with either cabinets or built-furniture. We already were planning to replace the rather thin shag carpet with a thick plush carpet over a dense carpet pad. This should help insulate the floor area in the aisle somewhat.

I know that this situation somewhat limits use in extreme cold weather, but we really don't have plans to do much in the extreme cold other than flee to places not so extremely cold. Oddly, even during weather in the 20s it was quite easy to keep the bus comfortable using the existing heating systems.

The wet bay also doesn't appear to be insulated, but it does have a small electric heater in place which presumably was installed during conversion to help prevent water freeze-ups. Not sure how to insulate the doors on this bay since they are the type of open straight up with a folding back layer, making it nearly impossible to just glue foam board to the back side of the doors.

Hard to believe that the original owners paid what they did for the conversion and didn't get an insulated floor. Maybe they had no plans for cold weather camping? Maybe in 1974 it wasn't considered important? Don't know, but it's sure strange.

Any thoughts? Should we just learn to live with the situation for now and alter our travels to accommodate the lack of insulation? Or is there a way to help the situation without having to gut the bus? Anyone have any luck retrofitting insulation in situations like this?

[Scott & Heather]

You can't really insulate a fully converted coach floor after the fact as you're already realizing. Two thoughts:

1. Your electric heater in your uninsulated plumbing bay should suffice. We never insulated either of our buses plumbing bays at all and a small electric heater kept anything from freezing down to -28F so you're likely ok in that department.

2. Even though you can't easily insulate your floor at this point, you could install electric floor heat underlayment. They sell rolls of heating grid matting that you can lay down, wire up, and then lay a floating click lock wood or tile floor over. This would be installed in main areas like living room and kitchen hallways and even bathroom floors. But even that requires lifting your carpet to install or adding flooring on top of your existing flooring.

3. Something that can work but may not be cost effective is to insulate your luggage bays and heat them nice and toasty. This warmth will radiate upwards to and thru your flooring and your floors will feel warm. It might be too expensive to heat those bays tho just to have warm floors. I suppose slippers are a cheaper option. Some guys on here have hydronic heated floors and I absolutely envy them to the point of jealousy.

Our first coach was like yours, nothing but plywood on the floor and the floors were always freezing. Our second coach we did it right and spray foam insulated the daylights out of it:


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[sledhead]

on my M C I    I put 3/4" foam board with the tin foil on each side under the floor with formica spray glue and the tin foil tape to seal ALL the seams ( lots of them ) it did take some time but helped a lot . before I did any work in ALL my bays I did the same thing and added 1/4 " ply on the bay floor  and put the grey boat carpet on every think other then the floor of the water bay . I just used the foam board and 1/4 " ply painted grey but no carpet . as for the bay doors I used rattle can spray foam inside the doors and the 1/4 " tin foil bubble insulation were I could not get any insulation in then used the tin foil tape on all to finish the job . not sure how much it helped but never had a freeze up in the water bay and I have been in really cold weather on some of the drives south ( as low as - 25 f )

on the featherlite they did a good job on all out side walls and ceiling and in the bays  but they only used 1/2 " crappy white foam board on the bay floors with the same boat carpet on a 1/2 " ply over the foam . some things they did are amazing and some are dumb

 

dave

[buswarrior]

Throw some rugs and forget about it?

Insulation is a false God, to whom too much worship is directed...

How much less headroom in the coach do you want?

Are the doors to the water bay air tight? If so, job done.

For arctic protection, the way to deal with baggage doors is to add framed, removable bulkhead immediately inside the door, to box up the water space inside, and the doors don't figure in to it.

Insulation doesn't heat or cool, BTU do that. You need a winning combination. So...

Cheaper and easier to add some BTU to compensate and move on to the next challenge?

Happy coaching!
Buswarrior

[TomC]

We too have only a 1" plywood floor with rubber flooring on top (transit bus). I did not insulate since I carpeted (no padding) the whole bus. Remember that heat rises-so floor insulation will only prevent hot from coming in the bus-of which good A/C takes care of. Cold air sinks, so cold will generally sink away from the floor. If the floor is cold or hot, some throw rugs may be in order. Good Luck, TomC

[richard5933]

Sounds like my plan to just lay the new pad & carpet and call it a day is the winner here. Doesn't sound like there's a great need to add anything at the moment, so I'll focus on more important items.

Thanks to all for the input.

[windtrader]

Standard fiberglass bat could be attached to the roof of the bays. That would provide several inches of insulation that easily conforms to pipes and other stuff already protruding from the bay ceilings. Easy to remove if needed, easy to adjust and move if needed by use of the bays.