Back at it again....OY!

[geof]

New trailer arived Tuesday-truck on the way here-maybe next week before arrival-who knows for sure?....started with the insulation last night....not used to all this work!....too much vacation and the rainey weather doesn't help the "authur-itis"....Income tax prep tomarrow so I can rest-them back at it Saturday and Sunday.....geof

 

[Guest]

What kind of insulation are you using?

 

[geof]

polyisocynate board called Tuff-R...6.3 per inch plus refletive foil....2 inches total with spray can foam as a gap filler.....trailer is 8'-2" wide 6'-8" high and 35' long inside with .063 alum sides- steel 1''X 2'' tube frame 16" on center sides and top-8'' tube X 12" on center frame-3/4" am-teck floor..Total R- factor is 15 top/sides-floor might be sprayed with polyiso/rhino if too cold....one 13.5 a/c and a fan for air movement and a 1500 watt heater.....geof

 

[Guest]

Geof. I am not sure of what the correct term to describe this is but im wondering about heat/cold transfer from a metal outer skin to the steel wall studs.

This might not be much of a problem in a trailer but I am considering a motorhome with a lot of winter use.

Even with good insualtion between the studs would there be a transfer of cold between the metal skin and metal studs creating cold spots.

I just used some polyiso for insulating a passive solar heating area on a house. 2 1/2 inches thick. Got some sheets left over from a bigger project. The price was right - free. I would be curious about what method did you use to cut the panels into smaller size to bit between the studs etc?

 

[geof]

.....In the Airstream in 10 degree weather the "hand thermometer" could just barely feel the aluminum studs with a constant 70 degree indoor temp. I was going to induce some steam to look for frost spots to check my work-but I got distracted and the weather warmed up. Followimg my winter vacation, when I got home form Florida, I got a deal on the new trailer-so I really got sidetracked as it arrived 7 weeks early so the Airstream is on a friends farm east of here. With the new trailer, an R-6.5X2" strip every 16" on center with an R-14 cavity insulated shouldn't make that much differance except in your neck of the woods where I would add another 1" of polyisocynate foam board for a R-21 or anotherwords R-14 over the stds with a R-21 filling for the walls and ceiling....the floor being another issue, as the heat loss is only 10% when not moving...another thing I would suggest is some alternate methods of heating your rig-if one unite poops out-which has been known to happen-there would be other ways of maintaining heat....maybe a combiation of electric and propane with the possibility of using engine heat through a series of heater cores and fans....maybe an indoor fireplace/wood heating stove/propane radiant energy source ......geof

 

[geof]

DUH!....cm...I forgot your last question....I'm using my panel saw or I could use my table saw to cut the foam sheets to fit snug between the studs....any gap gets the spray can foam......with a steel edge I guess I could get close with a box cutter if I was in the mood but I'd perfer the panel saw-'cuz I'm lazy.....geof

 

[Don in E Texas]

Our MC8 bus conversion has spray-foam insulation. No heat or cold transfer from metal exterior to inside --- interior is 1/2" plywood.

My Airstream is another animal. In the summer you can indeed feel the heat transfer from outside to inside. No comparison to the bus!!

FWIW

don

 

[geof]

Don-I have looked into the spray foam around these parts and the installers are less than relyable-so I'm doing the foam board.....spray foam is around $1.00 per board foot with you doing the clean up-whereas the foam board is 28 cents per sq ft not including labor which ammounts to about another 25 cents a sq ft.....the interior liner on my trailer is 3/8 inch Dougles Fir...I will have a 2 inch layer except for the 1"X2"square tube studs with the 3/8" plywood and the .063 Alum exterior....geof