We are getting ready to build a home in Kansas. We are using 2×6 on the exterior walls. We are looking at what would be the best insulation for us. Our builder mentioned something called “cellulose with boric acid” but he also said its pretty expensive.
So I was wondering what kind of insulation types should we get bids for? and which ones are worth the money and which ones aren’t?
Also we’ve seen a lot of Icynene stuff around here and from doing a little bit of searching it seems like a lot of their claims aren’t exactly true. What do you guys think?
Thanks,
–Carlos
Replies
cellulose with boric acid" but he also said its pretty expensive
Sounds like your contractor doesn't know what they are talking about. It is a very good product, and is no more than fibreglass ins.
About twice the cost here, but worth it.
Wow, have to check my prices again. I don't believe it is that much difference here.
I don't know about the boric treatment part, but last time I priced out blown cellulose it was less expensive than fiberglass batts.Justin Fink - FHB Editorial
All cellulose is treated for fire and bugs. Let me chime in ... the worst insulation is fiberglass batts. Blown-in insulation (foam, fiberglass, or cellulose) is the only way to go.
Just blown-in or dense packed?
loose fill...that may be where the difference is.Justin Fink - FHB Editorial
That must be it. I've gotten bids on at least ten fairly big jobs in the last year for different insulation options. On most of them I looked into closed cell foam, closed cell foam flash coat with fiberglass batts, dense-pack cellulose, and fiberglass, so I have a pretty good idea how those options compare in price here in southern Maine.
F/G was ALWAYS the cheapest of those options, full closed-cell foam was always the most expensive, with dense-pack cellulose and the flash-and-batt system fairly competitive at 50-75% more than F/G batts.
The cost difference between loose-pack and dense-pack is probably worth exploring. The cellulose packaging advertises coverage that works out to about .27/sf for R-19, but it's loose fill only.For 3.5" walls, even a 2.5 lbs/cu ft. dense-pack will run about 36 cents per sq. ft. at Lowe's price of $10.98 per 22.5 lb. bag. That works out to about R-13, which runs about .25-.30/sf in fiberglass batts.To be honest, I just did some dense-pack in my house without checking the cost/sf, but the overall cost was so low that I didn't worry about it.
I really, really, really want to do an article on flash-and-batt insulation. I think it's such a great idea with a high return on investment. Just makes sense to me.Justin Fink - FHB Editorial
I agree, but there is plenty of contention about it. Vabor barrier on the wrong side and all that. We've done several that way with mostly good results. Don't let clients talk you out of installing an HRV.
You don't have to tell me...build it tight, ventilate it right is my mantra!Justin Fink - FHB Editorial
JFink, did you take over for Andy? I was "gone" for awhile.What's "flash and batt?" Is that when they skim coat spray closed cell foam?I'm really out of touch ... what's a Mooney wall? Did FHB do an article on that?BTW, pixburd is the town where the Stillers won the Souper bowl.
No no no...I did moderate the forum for a few years after Andy left, but now it's in the capable hands of our web team.
Yes, that's essentially what a flash and batt is. And if you do a search on Mooney wall on breaktime you will find lots of threads - it's the brainchild of Mike Smith and Mooney. It's never been in FHB, but not for lack of trying on our part - they aren't apparentyl interested.Justin Fink - FHB Editorial
Pix
Here is a pretty good link to the Mooney wall.
http://forums.taunton.com/tp-breaktime/messages?msg=65624.1
Rich
This topic is one of the most recurring in this forum. The search function of this forum sucks but with persistence you will find several threads on foam vs cellulose vs glass.
There a several types of foams and other blown insualtions that are used in new construction. Blown cellulose is usually the least expensive and does a great job. Closed cell foam will give you the most R value per inch. These sites will get you started on what is available.
http://www.polymaster.com/
http://www.airkrete.com/
http://parpac.com/index.html
http://www.celluspray.net/faq.html
Blown in fiberglass in the walls should give you the best bang for your Buck!, Around here it cost less then blown cel. We got an R-22 in the 2x6 walls we did a few weeks back.
.View Image
Is that resilient channel installed horizontally?
Jon Blakemore RappahannockINC.com Fredericksburg, VA
Yes!
Does that "resilient channel" stuff work well? I need to sound proof our laundry room.
Is it cheap?
It works well is installed right. Most don't understand there is a top side & a bottom side to the stuff, needs to be installed with screws on the bottom so it looks like it's pulling away from the wall.
Not sure on the price, will check with my Drywall guy. We installed 2 layers of 5/8 type X on the wall in the photo, 1st layer vertical 2nd horizontal with sound caulk bead at the top & bottom plates. Also used putty packs at all electrical boxs.
The blown fiberglass gets packed tight with no voilds, which help on sound transfer.
On the RC, the screw holes should be on the bottom when installed, it's a 50/50 shot around here if they install the right way & I have had more then my share of guys that had to do it twice!
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The boric acid is part of the anti-fire chemicals added. Cellulose is just newspaper ... arguably the 'original' green building product. Cellulose w/ boric acid is not special cellulose, no idea why he said it that way.
And NO, it should not be expensive at all ... very competitive if not the lowest price. Normally, cellulose is the cheapest, although some of the guys are saying not. It's easily installed and fills more voids than fiberglass batt. Some say it resists air flow better than fiberglass. Also a good R-value per inch, so thermally it is good, too.
I think the borates are fungicide/anti-critter, no?
I always thought the chemicals were only for fire retardant. But I am no chemist ... worst subject in college. I did work making the stuff back in the mid 70s for a short time ... shoveling the chemicals in, etc. Always did a fire test, but never a rodent test ... :).
There's an insecticide/fungicide I've used a couple times, 'green' and 'safe' product called "Tim-bor" what is a borate salt you put in solution with water and spray on the nether regions of your building to keep the critters and rot away.
http://www.domyownpestcontrol.com/timbor-p-144.html
yes, resists bugs, molds, bacterium, and fire
, Oh - and body odor too.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Edited 2/22/2009 1:56 pm ET by Piffin
and body odor too.
and you know this how?
;-)
read it someplace.Not hard to understand - if the stuff stops growth of micro0organisms and if those critters feeding on human sweat is the cause of the BO, then eliminating the one will result in elimination of the other, right?And boraxo was used as a primary laundry detergent at one time. Remember twenty mule team borax commercials?
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
boraxo was used as a primary laundry detergent at one time
Still is!!
Piffin
When restoring my 100+ year old painted ceiling, borax turned out to be the best method of cleaning it.
The ceiling had alot of soot from kerosene lamps.
We used a paste solution of borax to gently scrub the ceiling.
Rich
better than TSP?
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Piffin
TSP was too aggressive.
We needed to gently clean the ceiling without removing the paint and the details.
We used a toothbrush in many places to clean around the details.
Here is the thread.
http://forums.taunton.com/tp-breaktime/messages?msg=86158.46
Rich
Edited 2/24/2009 1:48 pm ET by cargin
2 lb foam is vapor barrier, air barrier, and R-6 per inch. We spray it every day a nd it is awesome
I would say definitely the polyfoam. Rumble was right, it's far superior because of all you get. The thing about insulating is to stop air flow, and this does that and never settles like others leaving gaps.. It also stiffens the structure and adds much integrity to the building. It's more $$ but worth it by far.
Surprized one has suggested the "Mooney Wall". Do a search at the archives for mooney wall and it eliminates the thermal bridging a wall stud presents. Adding a fur strip to a 2 X 6 wasn't part of the plan though (7 in blown cellose) It should be warm
I'm working on Mooney walls right now for a small 1 BR house. Actually my son is nailing up the 2x2's. I think the cost/benefit is the best but I have no facts to back it up. I'll see how the Plumber likes it in a week when he does the rough-in (PEX). I got 100 20ft 2x4's culls for $2 each because they were cheap. Now I have a use for some of them.
Jim