Additional Insulation On Your Coach

[rsbilledwards]

This summer past another friend in Milton Freewater, Oregon insulated a portion of his 2000 Safari Zanzibar to enhance the heat retention of his basement cargo area. I looked at what he did and thought what a great idea.

So here it is: the cargo area is created by welding a framework of, in our case, both Safaris and all of the Safaris are constructed similarly, with 1 1/2 inch thin wall square tubing. The floor for the basement is laid on top of this framework and then carpeted. Underneath, outside are some large voids that we filled with foil faced foam, specifically 1 inch and 1/2 inch 4' X 8' foam sheets obtained from Home Depot. This stuff can be cut quite accurately on a small table saw or cut less so with a box knife and a straight edge.

Now since the framework was 1 1/2 inches deep, the foam board was sandwiched together with 3M spray contact adhesive also obtained at HD. I sprayed the bottom side of the floor and one side of a foam panel sized tight enough that they would stay put when placed in their respective cavities and then the same procedure for the next layer.

When all the cavities were filled I used some 2 inch diameter plastic concrete form retaining fasteners and 2 inch long, coated deck screws, 4 per panel to permanently retain the foam boards in place.

I was able to utilize this procedure on the inside side wall behind the 14 foot slide, both ends and the bottom of a portion of the coach floor. I boxed the metal heat registers installed below the floor (heat radiator to the heat the outside). There are numerous seams between pieces and as you might surmise one could not do the exterior wall in one piece with all the factory perforations for wiring, gas plumbing, chassis framing and such. All of these seams need to be taped for a number of reasons the least of which would be to prevent the accumulation of moisture but to create an integral unit of foam. A complication or deviation from the original plan. I also used the space aged foil faced bubble insulation which amounts to 1/4 in thick, as some of the framing had only an 1 1/4 inch shoulder or ledge.

In this case I tried to put the foiled bubble insulation on the inside and the 1 inch on top. This particular layering produces an insulating value of R12 or very close to it. There were some places where I used bubble and 1/2 foam board. There were places on the front and back wall where I laminated foam boards together with a layer of bubble in between the two as conditions allowed.

But as I stated earlier, it all needs to be taped with a 2 or 3 inch wide adhesive backed foil tape. I taped over all the plastic retainers. Home D did not have any of the really wide 3 inch tape and their 2 inch wide tape is very expensive when you consider what you get on big roll of 3 inch "Venture" which is the brand I used. There are others out there, look around you will find it. The HVAC community uses a lot of this material. The stuff is very sticky and touching your fingers does not seem degrade the adhesive value at all.

When I had panels where foam edges were exposed, I pre-taped the edges prior to adhering to the coach, with both the spray adhesive and the plastic retainers. I made special panels for the outside water bay as well. I used about 4 rolls of the 3 inch tape 1 roll 2 inch tape and 3 cans of 3M adhesive, and do not buy the expensive adhesive, buy the lesser of the two or three there. I think I used 6 sheets of 1/2 foam and 5 sheets of 1 inch board and 3 rolls of 24 inch wide foil faced bubble insulation. I paid special attention to the engine bay and the closet area of my Safari as I found numerous holes that allowed both dust/dirt and heat to engulf the bedroom, particularly heat after shut down.

In the end after shut down, there is less than a ten degree temperature rise in the bedroom!!! Prior, after a days drive open the windows for a while to cool it off. Another thing I did along this project was to add 3/4 inch insulation behind any cabinet I could get it into and when I did this I discovered numerous cold holes that were used by our nemesis, that 4 legged critter, the infamous "MOUSE". In my coach the hi-ways to heaven have been sealed up.

I had a blast doing this and at 70 I could not be happier with the results. There is still a big area up front from the cargo bay to the front firewall to do next summer and I will have a four season coach. The whole basement stays toasty with minimal heating effort which translates to warmer floor and a happier Misses.

[kaypsmith]

I think this is a great post, thanks for sharing.

Kay

[tbutler]

Great idea, great article. Additional insulation could also help reduce the interior noise level but I don't know if it would be significant. Have you noticed any reduction in the noise level in the coach when you are traveling?

[rsbilledwards]

It is quieter and should be more so when the front section is finished between and above the front wheel wells. I found the floor where the steering assembly perforates the floor was a big culprit for admitting noise and cold. The hole in the floor assembly was nearly 12 inches square with an aluminum sheet over it, the rubber boot, and a layer of carpet. This is not much for reducing either noise or cold. I packed 2 inches of foil faced foam into this area. It took a little time to shape it so as to allow minimum clearance around the shaft and universals. Another area that is quieter is the bedroom. The engine drone is definitely softer. B