I am getting insulation quotes from various insulation contractors. One is spec’ing an R-19 insulation for 2×6 walls and another is quoting R-21 for 2×6 walls. The R-19 contractor is telling me that it won’t make a big difference as the r-value difference is small.
Any of you have experience or an opinion on this one?
Thanks!
Ed
Learn more about the pros and cons of single-room ERVs.
"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.
Dig into cutting-edge approaches and decades of proven solutions with total access to our experts and tradespeople.
Start Free Trial NowGet instant access to the latest developments in green building, research, and reports from the field.
Start Free Trial Now
Replies
R21 is two more than R19.
Actually, the type of insulation might make a big difference. This will serve as a bump until someone better versed comes along.
http://logancustomcopper.com
http://grantlogan.net/
"We have enough youth, how about a fountain of smart?"
you should be choosing betreen colours, not numbers.
For insulation, there's pink, white, or yellow. You want pink.
In construction FG is OK for shingle matting and furnace filters... For insulation use foam or cellulose...Pink . . . this isn't the place to talk about that.
Breaker Breaker 19 You got yer ears on eddie?
Where you located?
over...
every court needs a jester
Rez,I am in New York, over...Ed
Well, a good heating climate then.
That means you have to wait for someone more experienced to lend an ear or research the old insulation posts in the BT archives to familiarize yourself with insulation techniques other than fiberglass batt
in that FBatts have been found to perform negatively in cold temps where the colder it gets the less insulation value as the Rvalues decrease approaching near worthless.
Thus the common consensus that FB ain't worth beans.
Mooney Wall, high density cellulose, foam boards and sprayfoams all perform much much better.
Cheers
be Happy Hunting
every court needs a jester
Edited 3/22/2007 10:33 pm ET by rez
I don't know where you are, but in OR new construction requires R-21 for 2x6 framing.
And sure R-21 is only 2 more than R-19, R-19 is only 4 more than R-15, which is only 2 more than R-13.
If you get someone else telling you they can put some nice comfy blankets in your wall, I'd turn tail and run.
I wouldn't insulate my house with fiberglass if they gave it to me!
Fiberglass is good for one thing: It makes cellulose and foam look that much better.
Consider dense pack cells.
Better at stopping air infiltration, better sound deadening, better at blocking radiant gain. And better at plain old insulating.
Foam ain't so bad either if you cen do that.
Mongo
If you go with anything above r-19 you might as well try for r-38. Heres why, although you may not notice right away the difference, as the electric company continues to increase the cost of electricity your home wont be affected as much because you will use less to cool your house.
The Electric company has done "cost vs value" reports on these things and use an "how long for return on investment" attitude when they recommend these things.
The Elec Comp says r-19 is the most for C/V. However, You wont be able to add more insulation in 5 to 10 years when the heat causes the batts to compress and lose their insulative qualitys. I have seen 6 inch thick batts compressed to 2 inches over time. that being said-
The most insulation you can possibly install now, the better for the long term.
Additionally if you dont have adequate attic insulation, attic ventilation and highly energy efficient vinyl windows with low e etc then go with the r-19 and keep the windows open cause heat and energy inefficiency have many ways of getting into your home. Fixing one without fixing the rest is definately a waste of money!
Many new building systems use R-40 to R-120
New Forum site: http://styrohomes.freeforums.org/
Fatal error: Call to undefined function: http_redirect() in /home/www/phpbb/includes/db.php on line 63
I never had a problem with character, people've been telling me I was one ever since I was a kid.
http://ergodesk.wordpress.com/SamT
Anyone who doesn't take truth seriously in small matters cannot be trusted in large ones either. [Einstein] Tks, BossHogg.
View Image
I never had a problem with character, people've been telling me I was one ever since I was a kid.
Insulation is a fairly good long term investment – up to a point. If my increased mortgage costs are greater than the potential for energy bills savings, then it is pretty bad investment. In my climate, somewhere around R40 to R50 in the attic and around R14 in the walls is the practical maximum.
<!----><!----> <!---->
It is also a fallacy to think that energy costs will continue to rise without stopping. My current electric rate is running around $.15 a KWH. Solar cells start to become cost effective somewhere around $.30 a KWH, even sooner if the cost of solar electric systems drop, and most experts believe they will.
<!----> <!---->
Cost difference would the first thing to look "at" for choosing.
Then, it gets a tad esoteric. Two more "R" might be good in walls that have over 50% window & door openings (as the best windows run R2, R3; Doors can soar right up to 5 & 6--with reductions for being operable).
There's an element of "bridging" unless one uses a Mooney wall that tends to obviate the "improvement" in R values, too. Now, if the extra 2 "R" is rigid over the sheathing, now, that's a way to "break" bridging, and that would be good.
Leave the pink for the tract builders & for around cheap refrigerators.