Insulation in walls and ceiling

[Pizote]

So... I started pulling the walls today and found the following:

* 2” of fiberglass insulation in the walls. All good condition.
* to get the walls off, in need to either:
A) pull the windows
cut the walls off just under the windows.

So here are my questions:
I get that closed cell insulation is better than fiberglass. But what’s the ROI on pulling everything out to remove so-so R-factor and replace it with slightly better? I prefer to insulate vs sound and temperature but it seems this is a high cost to get there both in time and money.

As for the windows, I like the look of them and will be sealing them where they will just provide light and not open. Followed up with insulation when needed. Seems like a lot of effort to remove the windows just to put them back in. They don’t leak so there’s that.

As for cutting the walls off, I can do that quickly, not an issue but at this point... why?

The ceiling will come down. It’s all screws anyway. So that’s not a concern. I will replace that insulation.

 

[o1marc]

The insulation in a bus is minimal, it was not designed for long term use during the day. The wall metal you will probably find is spot welded just under the window lip, so removing the window doesn't really gain you anything. Most of us cut that panel off just below the window line so better thicker insulation can be added in those cavities. I bought a $50 set of electric shears from HF, makes quick work of that metal and any other I'm using in the build.

 

[EastCoastCB]

I wouldn't call foam "slightly" better but to each their own.
I'm not planning on pulling the metal out of my shorty. Its just gonna be a weekend cruiser.

 

[Pizote]

I wouldn't call foam "slightly" better but to each their own.
I'm not planning on pulling the metal out of my shorty. Its just gonna be a weekend cruiser.

Me calling it slightly better is my lack of knowledge. In the few minutes since I posted I’ve removed one ceiling section and the insulation there is pretty poor quality as has been indicated.

I’ll cut the wall panels out this weeding. It would be a good use of my plasma cutter

 

[o1marc]

Me calling it slightly better is my lack of knowledge. In the few minutes since I posted I’ve removed one ceiling section and the insulation there is pretty poor quality as has been indicated.

I’ll cut the wall panels out this weeding. It would be a good use of my plasma cutter

Mines not working or that would have been my go to tool.. Woulda come in handy cutting in my RV windows. Gotta get that thing fixed.

 

[mrpincher]

R15 is much better

I'm slowly working on my bus and am past the insulation stage - so I can comment. It has been a rather strange winter in Amarillo this year. We've had short bursts of teens and 20 degree temps, always with lots of wind. This "winter" weather has given me a chance to sample the "environment" in the unaltered bus, the stripped bare bus, finally the insulated bus. I have R10 in the floors, R15 in the lower walls, R10 in the ceiling and upper walls. Major difference in the condensation; I now have zero condensation except around the front windshield and half dozen remaining windows. The bus is much easier to keep warm ( and should be easier to keep cool in summer). I'm able to turn the heater off much earlier in the day when it's really cold out. I wouldn't add more insulation - but I wouldn't remove any either. It wasn't cheap, I'd do it again.
Mike

 

[Native-SKO]

Mr Pincher, what products and thicknesses did you use?

 

[Ciscokid-SKO]

You will regret not pulling them windows out and sealing them in. This is easily seen with a laser temp gun you can get a wal mart or home depot. Insulation is priceless in a bus. If you splurge on anything I would insulate the best you can. These things are like toaster ovens in the summer and a meat locker in the winter. We have over done it with the ceiling and walls but sure wish I would have done more on the floor. The air goes right under the bus and makes it very cold.

 

[mrpincher]

Insulation

OK. I don't have a smart phone, pictures are on my camera...still.

Regarding insulation, I took the advice of our senior members on this forum and am glad I did. The condensation in my smallish 22 foot interior space was really bugging me . No longer the issue it was. My lower wall cavities measure 3 1/4 inches deep. They're filled with 3" of the Pink Owens Corning foam board from home depot. According to the manufacturer that = R15. I have the foam board glued tightly to the exterior metal. Mucho adhesives have been purchased throughout this build.

On the ceiling and above the windows I used the two part spray foam. Purchased on ebay and applied it without any hiccups. My job didn't exactly look as good as some of the professionals that I've seen on this forum. Its horrid stuff to apply. But I got the depth of insulation build up enough to fill the ribs of the bus + 5/8" = total of about 2 1/4 inches on the ceiling.

The floors have a 2" slabs of the pink foam board with 5/8" subfloor over that.

There's still condensation on the remaining side windows and on the windshield. I plan to monitor that as needed and plan to use the high tech "wipe it up" with a rag method to control that small amount of dampness.

Mike

 

[Ciscokid-SKO]

Are you using Propane to heat? It causes condensation very bad and not really any way to get around that with single plane windows. Dry heat will keep your bus from rusting and save you from chances of mold growing in hide away places.

 

[mrpincher]

Both

Hello

Yes I have a small unvented propane heater and an electric space heater. I know from use in my wood shop that unvented LP or NG heaters are terrible for depositing moisture in the air. I kinda wanted that "moister" environment in the bus so I could gage the behavior of the bus in a humid climate. Amarillo is sooo arid right now and not typical to the environments I plan to visit. I know...or hope I know, how the interior of the bus will behave in humid climates.

If my assumptions are wrong - please share your experience.



Edit = The bus internal humidity reading is 43% with the propane and electric heat running all night. The (temporary fog bank) outside RH reading is +/-100%. I have condensation covering about 3/4 of the winldshield and about the same on the side windows. No moisture on any other surfaces.


Mike

 

[HappyInTN]

So... I started pulling the walls today and found the following:

* 2” of fiberglass insulation in the walls. All good condition.
* to get the walls off, in need to either:
A) pull the windows
cut the walls off just under the windows.

So here are my questions:
I get that closed cell insulation is better than fiberglass. But what’s the ROI on pulling everything out to remove so-so R-factor and replace it with slightly better? I prefer to insulate vs sound and temperature but it seems this is a high cost to get there both in time and money.

As for the windows, I like the look of them and will be sealing them where they will just provide light and not open. Followed up with insulation when needed. Seems like a lot of effort to remove the windows just to put them back in. They don’t leak so there’s that.

As for cutting the walls off, I can do that quickly, not an issue but at this point... why?

The ceiling will come down. It’s all screws anyway. So that’s not a concern. I will replace that insulation.

I had many of these same questions. I opted to take the side walls and ceiling down remove all the insulation and spray in Lizard Skin thermal barrier and a sound control barrier as well (video link below on our youtube)! I additional put the 1' pink insulation from lowes back into the void. Now my R factor is close to R15 and much quieter and better for my kids allergies than the fiberglass was. We also found a few leeks while we were in there preventing future mold issues.

 

[GWRider-SKO]

There are several reasons why I would remove the interior panels, flooring, and insulation. Below are a few with some specific for my Crown and in no particular order.

1. Inspect for rust and/or repair.
2. Inspect for missing or bad welds etc. (my Chino Crown had some).
3. Add bracing if needed.
4. Inspect and add/or replace wiring (prefer conduit).
5. Replace or add lights, cameras or other fixtures.
6. Apply rust inhibitors and/or sound deadening.
7. Replace or add insulation.
8. Makes repair of dents or other damage easier.
9. Window removal and dry wall gap fix (Crowns).
10. Replace flooring containing MDF that did not get replaced during recall (mainly Chino Crowns like mine).

 

[Pizote]

Thanks all. I removed the ceiling and lower walls today. Removed the insulation as well.

During this process I came to the realization that I really need to purchase things now that I wanted to postpone - like a backup camera, rear and side flood lights, etc as I need to run the wiring to those locations.

I also realized that now would be the perfect time to run PEX, gas lines and electrical - before I spread insulate.

It’s all coming in at once now. Holding tanks, wiring, plumbing, etc.

Time to meditate and update drawings...

 

[Native-SKO]

Thank you mrpincher, HappyInTN, and GWRider for your posts. Y'all have provided invaluable information and testment to the benefits of doing the insulation job well.

 

[jimburke77502]

Is it something that no one is doing or is it just me?? In all the discussions on insulation here, I see no one using or mentioning anything about radiant barriers.

 

[Tango-SKO]

The trick with most radiant barrier material is having an air gap between separate layers. I applied Reflectix to the inner side of my outer skin...then another layer too the inner side of the inner skin. I ran a controlled test and found a nearly 30 degree reduction in transmitted heat on the outer skin.


NOTE: That skin also had two coats of paint with insulating beads mixed in.

 

[milkmania]

anybody got any feedback on the vinyl coated insulation batts they use in metal buildings?

 

[peakbus]

Thanks all. I removed the ceiling and lower walls today. Removed the insulation as well.

During this process I came to the realization that I really need to purchase things now that I wanted to postpone - like a backup camera, rear and side flood lights, etc as I need to run the wiring to those locations.

I also realized that now would be the perfect time to run PEX, gas lines and electrical - before I spread insulate.

It’s all coming in at once now. Holding tanks, wiring, plumbing, etc.

Time to meditate and update drawings...

Pizote, I'm exactly at the same point you are at. I was debating pulling the rear wall panels and panels below the windows. I did it yesterday and glad. When I pulled the rear panels and fiberglass insulation, I was wondering why they glued the insulation in so well on the back as elsewhere in the bus it was basically loose. Some areas looked like 1/4" thick yellow glue, or spray foam. Then I realized it was wet insulation that was frozen solid! You won't have that problem! I found some similar stuff at the bottom of sidewalls behind the chair rail. Time to seal those light fixtures (or replace) and windows. Ordered a Maxxair fan and backup camera is next.

So, what do people do to protect wiring coming through the walls when spray foaming? I though about boxing around the hazard light fixtures that project through the wall using rigid foam. What about the other random wires?

 

[peakbus]

anybody got any feedback on the vinyl coated insulation batts they use in metal buildings?

As a home inspector, that's about as worthless for R-value as what's in the bus from the factory. It's basically used as a vapor barrier to prevent condensation.