New to this - Structural, Heating and Insulating Questions

[Ilexis]

I bought a bus last week with the intention of outfitting it for full-time living.

I have chemical and electrical sensitivies, so a lot of things that are different from the "norm" to keep the indoor air pollution and electromagnetic fields as low as possible.

The bus is a 2002 Blue Bird, 53 passenger capacity.

I would like to beef up the insulation, and replace it with a different material, but want to keep the structural integrity of the bus. I'm wondering, has anyone tried keeping the interior walls in and building a new sheathing a few of inches inside of that to add extra insulation? Can you see any problems with this? The thing that comes up for me intuitively is that the metal between the two layers of insulation might be an area of condensation that encourages mold.

I'm looking at using hot water radiant floor heat, and adding insulation beneath that on the underside of the bus, including around the water tanks. I might run some of the radiant pipes around the water tanks for winter protection. Does anyone have experience with hot water radiant heat on a bus, or with insulating beneath the bus? Of course I don't want leaking, which would also encourage mold. Another question I have is how to keep animals out of that insulated space, but still make it easy to open and remove the insulation for making repairs to the bus.

I'm also interested in the possibility of adding insulation above the roof - sort of an attic space built onto the outside top. Has anyone tried this? Because I want to minimize my reliance on electricity, I'd like to install a water tank up there, to make a gravity fed system. The idea is to have a pump that can be used at the time of filling to raise the water to the roof, then rely on gravity for showers and sink until refilling time.

I'm also wanting to add a back porch (about 3' deep) which would hold the propane refrigerator, the boiler for the radiant heat and some storage. From what I've seen here, it looks like others have put on porches, but maybe not holding this much weight? The fridge I'm considering weighs 112 lb. The porch will probably be at least partially enclosed, and I'm considering moving the back 3' door to the back of the porch - effectively, it would be kind of a mud room and keep the fridge and other generators of pollutants in a separate air space from the rest of the bus.

Does anyone see any issues that could come up with any of these ideas? Other than the cost an effort, I mean, which I know will be significant!

[Ponyracer]

I'd think twice about the gravity feed water tank on the roof, especially if it's a large one. 7lbs per gallon or so? Not to mention the sloshing and unregulated movement in an unbaffled tank. As far as the "mud room", as long as the add on is designed not carry the weight, tied into the frame with thick walled tubing etc. I am prob doing something similar that will fold up when not needed, used to carry a 1000lbs of motorcycles.

[lornaschinske]

Originally Posted by Ilexis

...has anyone tried keeping the interior walls in and building a new sheathing a few of inches inside of that to add extra insulation?

Yep we did. We only added 1" of foam board insulation with a radient barrier on it.

Does anyone have experience with hot water radiant heat on a bus, or with insulating beneath the bus?

Our radient heater is on hold until we get a homebase. Insulation (foamboard with canned foam to fill in where needed) under the bus is fairly easy. Not a whole lot different than insulating the subfloor of a house. You just need to cover the foamboard with a rigid cover to protect from road debris. Something along the lines of metal roofing panels. Just make sure you seal all seams from water infiltration.

I'm also interested in the possibility of adding insulation above the roof - sort of an attic space built onto the outside top. Has anyone tried this?

Super Insulating the Roof by George Myers

[somewhereinusa]

Does anyone have experience with hot water radiant heat on a bus

I have it in my bus, not all finished, but I use it. The boiler installation is done and operational. Bedroom is done and operational. I tied it in to
the bus heaters in the front and it is operational. It works great Even with less than half of the plumbing done it kept the bus comfortable, although a little
chilly in the middle, last weekend. We had our first heavy frost so I'm guessing temps were somewhere around 30.
I haven't written up complete description yet, some pictures here.

http://somewhereinusa.x10.mx/heat.html

and there are some descriptions somewhere in here

http://www.skoolie.net/forum/viewtopic.php?f=9&t=9827

The heat is tied into the engine cooling system through a water to water heat exchanger, as is the marine water heater. I was a little concerned about how well that
would work, but I get hot water all the way up to the front while driving. There are four zones, bedroom,bath room,kitchen/front room and front heat/defrost. The back
three are controlled by thermostats that turn on the circulation pumps. The front heat/defrost is controlled by a switch on the driver control panel.

It sure is nice to have toasty warm floors.

[Ilexis]

Thanks everyone for the responses. ponyracer, I'm glad to hear I'm not alone in the porch idea. I'm definitely not planning to put 1000 lb on it, unless I decide to have a party! Others have tried to discourage me from the gravity fed system too, sadly.

somewhere, thanks for the link to your photos. The system looks complicated, and me wanting to get this done before it gets really cold this winter! I know that's not super realistic, but the need for a place to be is pushing me to try. Your driver foot heat setup looks like a nice touch!

Thanks lornaschinske for the tips on insulating. I'm wondering, have you noticed any issues with moisture condensation with this setup?

[lornaschinske]

Originally Posted by Ilexis

Thanks lornaschinske for the tips on insulating. I'm wondering, have you noticed any issues with moisture condensation with this setup?

We are in an area where the humidity is normally low. But in the monsoon season when the humidity rises to decent levels, we have experienced no problems. Our bus has OEM insulation in the sidewalls and ceiling. With the foamboard insulation we added to the interior along with the thermal breaks, the metal panel sandwiched in the middle should maintain a stable dry temp. If you do the radient barrier type insulation, the shiny side faces towards the living area. Too many folks install it wrong. Just like too many install a door lock wrong.