| Author |
Message |
captain ron (Captain_ron)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 26, 2006 - 12:18 pm: | |
My friend gave me 14 sheets of 3/4 inch styrofoam
its the white stuff not real dence like the regular insulation stuff. Should I use it in me walls or not? if not Why? |
Ron Walker (Prevost82)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 26, 2006 - 2:33 pm: | |
No..use the high density. The white doesn't have very much R value. |
ChuckMC9 (Chucks)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 27, 2006 - 1:58 pm: | |
I'm researching this hard-to-get-a-handle-on issue right now.
Here's some preliminary notes - any corrections or comments most welcome.
Insulation R Values
Fiberglass, normally found in houses: R3.1/inch
Styrofoam/Polystyrene/beadboard: R4.0/inch (white, needs vapor barrier)
Polyurethane board: R6.6-7.8??? per inch???
TUFF-R polyisocyanurate foam board: (Dow Building Matl's) R 6.7 ??
Polyisocyanurate (polyisocyanurate foam) is R-6.5 for 1" and the spray-in is R-7 for 1".
Look for 'Rmax' brand it is a polyisocyanauranate foam, very similiar to polyurethane and has an R value of 7.2/inch which is better than the styrene foams, which are about R4-6/inch and very much better than fiberglass which is about R2-3/inch.
Bubble Foil: R7.8 w/ 3/4" airspace on each side
===========
Heat flows from higher temperatures to lower temperatures by three mechanisms: conduction, convection and radiation.
Radiation accounts for up to 93% of the down heat flow, 50-70% of the up heat flow, and 65-80% of the side heat flow.
Convection accounts for almost none of the down heat flow, 45% of the up heat flow, and 15-28% of the side heat flow
Conduction accounts for 5-7% of the heat flow in all directions - up, down, and side.
Insulation only affects conduction and radiation.
Insulation acts as a resistance to the flow of heat.
The high temperature flows toward the low temperature and the flow is resisted by the insulation.
If you have BCMag, there's an interesting article from March, 2004 titled, "Getting an Insulation R Greater Than 50," in which the author advocates sealed radiant shielding + Tuff-R. |
james dean boggs (Jd_boggs)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 27, 2006 - 11:57 pm: | |
Use the spray foam. It works better at getting into cracks and voids. It's called "Handi Foam". Very easy to work with.
These are pics of my project and shows how I used the spray foam. http://www.promarc.com/hobbies/Insulation/index.html
And you can see videos of the foam here: http://www.absealantsltd.com/Fomo_More_Info.htm
Good luck. |
Sojourner (Jjimage)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, January 28, 2006 - 7:14 am: | |
Ron asks questions and got well searched answers.
A special thank you note to Chuck MC9 for his full “R” value report. Applauses
Might add that Polyisocyanurate come laminate paper on inside or dull surface & aluminum foil on outside but Styrofoam/Polystyrene/beadboard doesn’t. It easyier to knife cut for cleaner smoother edge like sheet-rock.
For curve section… kerfs cut every 1 inch on paper side to bend. Better yet….using 2 or more pc of 1/2 “ layer to keep “V” (cut) areas small or narrow. Otherwise thicker pieces for flat surface.
Yes ...hot-foam is better still at higher cost.
FWIW
Sojourn for Christ, Jerry |
Cory Dane
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, January 28, 2006 - 5:25 pm: | |
I had also gone through a lot of this.
I had talked to a manufacturer and they suggested BOTH the foam, against the wall,then the bubble foil on the foam. The reflective bubble foil needs a 3/4 inch air space between it and the outside wall to work at keeping the outside heat out. You will also need window coverings such as the honeycomb type for best insulating value and keep the heat out/in.
He had told me that foam alone or reflective bubble foil are limited in ability to keep temperatures at bay. Installing both will make your chances much better.
The biggest problem will the the windows where I suggest using a reflective window tint AND the window coverings.
hope this helped.
cd |