Any floor insulation advice?

[turtle]

Hey there! I'm new to bus conversion, and am looking to get my floor installed on my 1978 International Harvester Loadstar (about the size and shape of a short school bus). So far I have the basic metal floor of the bus and roughly 3/4" wood covering that. The wood that's there came with the bus and seems a little like plywood, it may be more dense, but pretty close. Some holes are drilled in the flooring here and there. I want to have a full time life on this thing and am in a commonly wet and cold place. I'm in Washington, but plan to travel in a couple of years. I'm interested in what to use to prevent mold, keep clean, and insulates. I've had suggestions about using more wood. There is a little leakage from the back exit door, so I need something to keep water from getting into the floor and not trap it. I'm interested in your suggestions!

Thanks!
Turtle

[mouse059]

Hey,

These threads will help you

Flooring Options
Spray foam under floor
Rusty metal floor
Subfloor Installation

[turtle]

Thanks for the ideas macgyver! I agree, I'll be taking care of that leak Is there a certain kind of vapor barrier that works better than others?

Thanks for the links Mouse059! I'll check'm out shortly!


Thanks to both of you,
Turtle

[the_experience03]

Any farm and fleet type supply store should have 3 mil plastic sheeting available in rolls of various dimensions. Get the one closest to the size of your bus allowing for some overlap and go to town.

[turtle]

Great advice ya'll! Thanks much for the welcoming feedback

Turtle

[Diesel Dan]

Smitty mentioned in a thread somewhere that if I'm not going to go all out and insulate walls and ceiling, then there's not much point in insulating the floor.

I'd like to explore that concept.

Is insulation an "all-or-nothing" proposition? Should I even bother insulating the walls if I'm going to leave most of the windows alone?

My plan is to paint the exterior roof with that insulating/reflective paint, and I had considered putting a thin layer of insulation on the walls, but most of my windows will be left "as is" so passengers in the back can see the view.

I'm not willing to sacrifice any headroom so I won't be putting insulation on the floor, other than 3/4" plywood. Seems like a radiant barrier on the floor might help to keep the heat from the pavement from coming up through the floor regardless of whether or not I insulate anything else.

So does this plan make any sense? Should I even bother insulating the walls if I'm not going to get insulated glass or seal off a bunch of windows?

[Diesel Dan]

Macgyver,
I'm more concerned with enduring high temperatures as opposed to cold weather. I anticipate my travelling will be done mainly in the summer. So no, I don't want to trap heat in my bus; rather I want to trap the cool air produced by my A/C in the bus, and at the same time keep the outdoor hot air out of my bus. I would think that a radiant barrier on the floor would keep heat from rising off the pavement and into my living space through the floor. The white reflective paint on the roof would prevent the sun's heat from heating the metal of the bus which would eventually radiate into the living space (I assume that is the reason why all school buses in Texas have white roofs).

[Diesel Dan]

Thanks for the words of advice guys. I'll definitely give some serious thought to insulation. I'm flying out to Kansas tomorrow morning to pick up the bus, and will be sleeping in it at least one or two nights with temps probably below 40 degrees. So that will give me a good opportunity to contemplate insulation . I'm bringing a couple of small electric space heaters with me, so we'll see if they do anything to keep me warm. I'll bring my camera and take some pics, and report back when I get home and start tearing into the flooring.

Okay, I'd better get some sleep - big day tomorrow!

[westernflyer]

Eek i'd stay away from any vapor barriers. Just a way to trap moisture and speed up rust.

[turtle]

Originally Posted by Smitty

Something someone here mentioned once was dividing the drivers area from the rest of the interior.
Smitty

I think that's a fabulous idea. I'm going to build a wall with plexi glass windows and a door that will devide the drivers area from the living space.

Turtle

[mouse059]

I was thinking about just using a very heavy curtain to keep light/sound/heat and air contained between drivers & the cabin.

[John]

That's what we're doing now. We have a surplus army blanket and a decorative sheet that we use to isolate the entire front of the bus from the cabin. We've been getting lows of 6 degrees under and its a very good way to keep the front door and windshield from drafting. I have not left it up while driving and don't have any plans to.

It makes a kind of porch, where you can open the door and enter the bus. Then after closing the door you can open the curtain. It also gives us more privacy as the front of our bus faces the road and the view from our door is blocked to those who peek before knocking.

I removed the metal paneling above the drivers seat and above the door, just the basic inside skin. This left me with a metal lip. I clamped the blanket / sheet to the lip with a couple of basic carpentry spring clamps. The area above the door is also used as a shelf for keys, etc... This does leave a gap between the top of the blanket and the ceiling but the blanket goes all the way to the floor.

[turtle]

Originally Posted by mouse059

I was thinking about just using a very heavy curtain to keep light/sound/heat and air contained between drivers & the cabin.

That would be easier to build. I'm considering this idea, too. I'll post something on my blog about what I end up doing. I suppose heat escaping through the cracks of a door is similar to heat escaping through the sides of a curtain. I can't imagination one works any better or worse than the other.

Take care,
Turtle

[Sojakai]

Not to mention that they make toasty blankets, and folded in half, they are great cushioning for under sleeping bags.

[turtle]

Originally Posted by Smitty

Something you might look into is a heavy/padded moving pad. They're pretty thick, and I'd have to think would work well as a divider/insulation.

Smitty

It sounds like a good idea.

Before, I get that stuff down, I need to solve a mystery...

I've been seeing egg sized puddles in 2 or 3 different spots of the bus. The spots change location nearly every time. In October, when it wasn't quite as cold, I noticed this happening, but thought they were leaks. Since then I've sealed where I thought it may have been leaking from and painted and sealed the floor. Now that the floor is sealed, I can see that there are no trails leading to these puddles at all. Surrounding each puddle is a happy, dry, painted wood surface. Being in Washington state in the winter, I thought it maybe condensation, but aside from a little on the windows, water is nowhere else (except for small a leak I need to figure out in the very front of the bus, but that's another story). The ceiling is also completely dry! This has been a mystery to me. Any thoughts about what this could be, or how to fix it? Has anyone else seen this in their vehicles?

Thanks,
Turtle

[Redbear]

Originally Posted by turtle

Before, I get that stuff down, I need to solve a mystery...

I've been seeing egg sized puddles in 2 or 3 different spots of the bus. The spots change location nearly every time. In October, when it wasn't quite as cold, I noticed this happening, but thought they were leaks. Since then I've sealed where I thought it may have been leaking from and painted and sealed the floor. Now that the floor is sealed, I can see that there are no trails leading to these puddles at all. Surrounding each puddle is a happy, dry, painted wood surface. Being in Washington state in the winter, I thought it maybe condensation, but aside from a little on the windows, water is nowhere else (except for small a leak I need to figure out in the very front of the bus, but that's another story). The ceiling is also completely dry! This has been a mystery to me. Any thoughts about what this could be, or how to fix it? Has anyone else seen this in their vehicles?

Thanks,
Turtle

Do the spots feel colder than the rest of the floor? Moisture could be condensing on any cold spot. Are these spots where seat bolts used to be, maybe? Even worse, are there bolt shafts left in the plywood with their heads cut off, conducting cold in by a "thermal bridge?"

Moisture content is not easy to calculate, but I once tried to get a rough idea of it. I once saw a wall in a house with plaster bulging in winter. The wall was most likely getting ice inside, and one of the owners said it had to be a leak in the roof. I was pretty sure it was warm inside air exiting down from the attic, cooling and condensing water that was freezing as the air went out through the clapboards. The rough result of my calculations was that the amount of air that can hold a gallon of water at room temperature and 50% humidity could only hold one quart at 32°F and 100% humidity. This meant the air had to condense out 3/4 of the water it was holding in order to cool to the freezing point.

I can't say this is your problem, but it's the only thing that comes to mind. Oh, and congratulations on having such good friends to work on your bus with you.

[turtle]

Originally Posted by Redbear

Do the spots feel colder than the rest of the floor? Moisture could be condensing on any cold spot. Are these spots where seat bolts used to be, maybe? Even worse, are there bolt shafts left in the plywood with their heads cut off, conducting cold in by a "thermal bridge?"

Moisture content is not easy to calculate, but I once tried to get a rough idea of it. I once saw a wall in a house with plaster bulging in winter. The wall was most likely getting ice inside, and one of the owners said it had to be a leak in the roof. I was pretty sure it was warm inside air exiting down from the attic, cooling and condensing water that was freezing as the air went out through the clapboards. The rough result of my calculations was that the amount of air that can hold a gallon of water at room temperature and 50% humidity could only hold one quart at 32°F and 100% humidity. This meant the air had to condense out 3/4 of the water it was holding in order to cool to the freezing point.

I can't say this is your problem, but it's the only thing that comes to mind. Oh, and congratulations on having such good friends to work on your bus with you.

That's an interesting idea I hadn't thought about. All of my bolts are removed except for 7 screws I had to drill the heads off of. The screws haven't had any puddles of water over them so far that I've noticed. I'll keep a close eye on their locations.

Thanks for the help and the congradulations


Turtle

[RazorCityDen]

I thought long and hard about insulating the floor of my bus.

Ultimately I caulked the seat holes, caulked the edges primed it and started framing.

The 3/4 plywood floor in my bus was in such good shape it seamed a shame to rip it up and also as I started layout I realized just how much of the floor was going to be cabinets, closets and the full size bed with storage under it, all dead air spaces that will help "insulate" the living space. The exposed floor is going to get a free floating laminated strip flooring that goes over a 1/4" closed cell pad, over that will be throw rugs. I also liked the idea of anchoring the framing straight though the 3/4" plywood and into the metal floor pan instead of sandwiching foam in the middle. There is a lot of floor hidden that will get some foam on it and other odd voids that will get stuffed with bat insulation.

The window openings that I skinned got 1 1/2" glued to the back of the skin. The side walls exposed to the living quarters (not very much) all got furred out 1 1/2" and will get more foam. There are quite a few voids that will get bat insulation stuffed in them before they get buried behind cabinet spaces, paneling and the built in closet inserts and storage inserts.

I was going to use the original metal bus ceiling as the finished ceiling in the living area's, but so much of it's covered with cabinets or hidden I'm going to hang a thin paneling attached to the metal ceiling with screws and decorative washers, probably over the same closed cell underpayment as goes under the flooring.

I often work inside my bus when it's hovering around zero and the wind chill well below zero, heating it only with a small wood stove and never burn more than a partial 5 gallon pail of wood a day, scrap lumber at that, if I had good firewood I
probably wouldn't use as much.

IMO I think it hard to tell just how much the hard core, super insulating would have really helped. When I can just toss another piece of wood in the stove and open the damper a bit, making it hot enough though out the bus I'm in a t-shirt and my beer starts getting warm before I can drink it.

[turtle]

Originally Posted by Smitty

You're likely seeing the puddles in different areas because the sun is warming the areas differently, the wind is changing directions, etc. depending on how/where/orientation you're parked. Each place, or season, will change. Water (condensation) can run off anything overhead, making it hard to locate its source sometimes. Insulation/vapor barrier/ventilation is the only way to prevent it (talking condensation). Those who fail to address these issues at the beginning of their conversion will pay the price later on.

Smitty

I can see this being a possability, too. I'm keeping an eye on it...

After thinking on it and helpful suggestions from others, I decided I need to tear up the plywood I painted on before. Perhaps, after reconstructin the floor I'll be able to get a better idea of what is going on with these weird water spots.

Thanks for the thoughts,
Turtle

[turtle]

Originally Posted by djontz

FWIW, I agree with Smitty...you can't be too careful about insulating and doing whatever you can to stop condensation. You are going to spend a lot of time and hard earned money on this project. You won't want to have to redo parts of it a couple of years from now.

I agree!