I have recently finished framing an addition onto my northern Illinois home and I have a few questions on how to insulate. The house has tyvek brand wind barrier on the exterior, 1/2″ osb sheeting and fiber cement siding. The house is mostly framed of 2×4 walls (some 2×6). I have read many debates about types of vapor barriers. I guess my question if should I use unfaced fiberglass insulation with a 6 mil vapor barrier? or should I use kraft faced insulation? If I do use unfaced, what is the best method to hold the insulation in the stud space? Does the fit of the insulation to the wood stud provide enough friction to prevent the bats from sliding down into the space? I read a story about a contractor using a 6 mil poly vapor barrier on ceilings below an attic and the drywall began to fall of the ceiling after time due to condensation build up. I surely do not what this to happen. I am intending on using the unfaced with a 6 mil. poly vapor barrier, but is this a bad choice. Will the house not “breath” as will or be too tight with this type of vapor barrier? I am not in the market to do spary in insulation, as I would like to do this part of the project myself. Input please!
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vic... go to the heading " heating & energy" click on the blue header..
you'll see about 10 threads that discuss all the pro's and con's of various insulations and vapor barrier..
bottom line... foggeddabout the fiberglass
Mike Smith Rhode Island : Design / Build / Repair / Restore
What do you mean forget about the fiberglass? I go and check the heat and energy section. Thanks.
What he means is FG has lousy performance compared to spray foams and celulose. Id recomend getting yourself large rolls of the reinforced plasic sheeting(it wont stretch or bulge) and attatching it to the walls then blowing cellulose into the walls. You can rent the equipment your self.
What type of reinforced plastic sheets do you mean? Where can I get them?
Its a specially made plastic that has a synthetic fiber imbedded in the plastic so it wont stretch or bulge when you blow DRY cellulose into the stud cavities. Also lets you to see the progress you are making in each stud bay. Not sure where you can get it, but I would think if you can find a wholesale supplier of cellulouse(not HD), they would have the rolls of plastic too. BTW the plastic is only used in new or complete rehab work where the entire inside of wall is exposed. Otherwise you would drill holes from the outside and apply it that way. Look at FHB #160 January 2004 pg 52. In the paragraph "In walls, pack it in" they make mention of it. Mayby somebody here can point you towards a suplier.
around here, it is not good to put a vb on ceiling. it traps too much moisture and mold will grow on the ceiling drywall. Most will be on the backside between the drywall and VB..
nuthing but happy thought.
"around here" meaning notthern Illinois?
Brownbag is in Florida on the Gulf Coast. VBs in a hot humid climate are treated very differently from the northern heating climates so you don't need to worry over that one..
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there are 2 kinds... the old one was a 1/4" mesh..stapled and glued with PL200... lots of blow thru until the fabric clogs , then the material packs behind it..
the new style we use is a spun fiber... stapled and glued with a latex glue that looks like wall paper paste..
we get the fiber and the glue from Regal Industries... which i think is in Indiana..
some of the other posters put me onto Regal.. great company.. they also sell blowing machines and, of course, cellulose..
http://www.regalind.com/regal_wall.htmMike Smith Rhode Island : Design / Build / Repair / Restore
The spun fiber-does this also act as a vb or is no barrier needed when you use cellulose?
no VB needed with dens-pack cellulose....
did you find the regal site ?
good company.. i enjoyed doing business with them... we'll be blowing cells on the dormer job i'm posting in the photgraphy sectionMike Smith Rhode Island : Design / Build / Repair / Restore
Yes I did. Thanks for the link. Do you do your own insulating work? If so, what could I expect the cost to be?
The cost of cellulose(sorry).
about $6 - $7 for a 26 lb. bale....
so.. if you're blowing loose fill.. the settled density is 2 lb/cf
dens-pak... figure 3 - 3.5 lb/cfMike Smith Rhode Island : Design / Build / Repair / Restore
Just one thing to emphasize...
If you're going to do the cells, understand Mike's post when he writes "dense pack."
Just blowing the cells into the stud bays in a somewhat offhanded manner will fill the bays, but you may not get the long-term performance that you want, you may end up with the cells settleing. You need to dense pack.
As Mike wrote, try for 3-3.5 lbs/cu ft finished density when you blow. How to figure? Figure the volume of your stud bay cavity, then make sure you're pumping in enough cells to reach the desired density.
An 8' tall bay, with 2x4 framing 16" oc, will be about 3 cu ft in volume. If you want 3 cu ft density, then you need to pump 9 lbs of cells into each bay, a 25 lb bag should fill slightly less than 3 stud bays. To get the full 3.5 lbs per foot, you'll use about 1.25 bags per three stud bays. I hope that makes sense.
End result is that if you're filling four bays per 25 lb bag of cells, something ain't right.
A very easy training tool is to do a mock-up of a wall. Take five 2x4s and two sheets of ply. Cut one 2x4 in half to use as the top and sole plate, use the other four 2x4s as studs. Build a little wall with three stud bays and use screws to skin each side with a sheet of ply. Cut a hole for access to each bay and stand the wall up so you're blowing into a vertical bay. You should be able to fill all three bays with one bag of cells, and if you're doing a righteous job, it'll take slightly more than a bag...about a bag and a quarter.
After blowing, unscrew one sheet of ply from the mocked up wall to get a look at how well you're filling the bays.
Learn from what you see, or if all is well, run with it.
hey , willis... that sounds like the wall mock-up i made when i had to learn how to dens-pak.. and we also took all the cells out and weighed them...
another life-skill learned....Mike Smith Rhode Island : Design / Build / Repair / Restore
Did the same thing on my side fo the fence way back when, Mr. Drummond.
I didn't get nearly as many sideway looks with that one as I did when I did the mini-roof mockup...to compare various combos of FG/cells/polyiso...for finishing off attic spaces.
The price we pay for glory...<g>
Mike/Mungo:
When you purchase cells is there any difference between one brand and another? Is the stuff at HD or Lowes just as good? I mean I could see ordering the mesh and the glue, but it would seem that the shipping costs on the cells itself could be prohibitive... I would guess the ASTM or UL or someone would make them treat it all with some kind of fire retardant - what about insects...
Thanks,Matt
we blow National Fiber that we buy from Insul Mart right outside of Providence... all of the bags and literature have the following specs:
CPSC Standard HH-I-515E;16CFR 1209
Meets ASTM C739-97
Class1 Building Material
ASTM C739 defines the characteristics
Flammability ,Enviornmental, Physical Characteristics (open blow) & Physical Characteristics (sidewall-dry)..
i would imagine any cells mfr. would be using the same testing and specs...
i'm getting ready to test some wall paper glue as a substitute for the fabric adhesive i was buying from Indiana... the spun fiber i can also get from Insul Mart... i don't think their fabric is as wide as the stuff i bought from Regal though..
Mike Smith Rhode Island : Design / Build / Repair / Restore
A couple of years ago I was at the local home show. Several cels insulation installers where there. Mostly wet blown.
One of them has what appeared an ultifine, gray cels. The other some some texture and while all gray, showed some tonal variation.
The best that I can describe it is the difference between MDF and particale board.
Who claimed their's was better?
;-)
Matt
I really don't know. Don't even remember if I asked them about the difference.
It was a joke...
Matt
I bought the Insulweb from Regal, but I used Home Depot wallpaper paste (Golden Harvest Premium Paste for Unpasted Wallpaper). All I'm looking for is enough adhesion to keep the cellulose from getting between the Insulweb and the stud, and it seemed to work fine (I let it dry overnight).
r; Let us know how it works.the dense pak system sounds pretty good
OK. I doubt I can add much that hasn't been said before, but here goes: I'm an amateur remodeling the upstairs of my old, balloon framed house. Tore off the ratty 3/8 drywall on all the exterior walls to find no insulation whatsoever in the stud cavities. The balloon frame makes a perfect application for the blown in cellulose. Some of the stud cavities I can fill all the way down to the mud sill, and even when I'm above a window or hit some type of blocking, my attitude is, "well, it's a whole lot better than before". I bought the 48" X 125 yard roll of insulweb from Regal (1-800-848-9687. cost = $46.65). I stapled up the insulweb to the top half of the wall only, then went around the room and put in the first course of sheetrock horizontally. (That way I don't need the 8 foot wide insulweb, and it's easier than trying to slip the mesh behind a board that's already up). The night before I'm ready to go, I put the wallpaper paste on the mesh with a small paint roller and let it dry overnight. At my HD, the blower if FREE (whether you buy insulation or not); they just put a huge deposit on your credit card and credit it back when you return the machine. The bags of Cocoon cellulose are $6.47 each at HD, so the whole process is very cheap (I would almost guess the cost of the material is paid for in the first full heating season). Cocoon says there is a "sidewall kit", but my HD is clueless, so I just jam the hose as far down as I can in the stud cavity. When the sound changes, I pull it up about a foot, repeating that until I've pulled the hose almost out and the mesh bulges a little.
Watch out for tiny holes in the hose - I finished last time to find about one cubic foot on the downstairs floor !
Edited 1/28/2004 1:30:03 PM ET by r
sounds about right... a few minor points...
most machines have a valve for mixing the air /cells... the less air.. the more cells... the more cells the greater volume thru the hose and the more chance of clogs in the hose..
but..
it will also clog faster in the stud bay.. and you will get voids and not acheive the density you want..
a couple things you can do... boost the air.. and watch the hose.. most are semi-transparent.. you can see the cells moving thru... i don't like to see a lot of cells
2d .. most hose ends are 2 1/2" tube diameter.. or 2".. i like to get a common 1 1/2" 45 elbow fitting and reduce my hose end to 1 1/2 ".. the angle on the end helps to aim the cells... the smaller diameter has a venturi effect and accelerates the cells comming out.. ( more air + greater acceleration = cells slamming into each other and the stud bay and PACKING tighter )... hence "dens-pak"
on your lower walls, where you hung your board.. you can drill a 1 1/2" hole about a foot off the floor (even under the windows )... and blow the bottom with your 1 1/2" elbow.. later , patch the holes.... they even sell 1 1/2 foam plugs just for this..
then .. poke a hole a foot from the top of the bay and blow the top... then poke a hole in the middle of the bay , thru the mesh and blow the top middle and the bottom middle..
the guy in the JLC article uses a long flexible tube to accomplish the same thing.. blowing the bottom... the top.. and last , the middle.. his tube is also reduced in diameter..
the 2" - 2 1/2" tube is for open blow in atticsMike Smith Rhode Island : Design / Build / Repair / Restore
I just contracted with a Nu-Wool installer to blow my 1200 sq attic...new construction...with Nu-Wool. He's going to do it Saturday. I'll be there with checkbook in hand. Anything I should watch for that are common errors in open blowing cellulose? Or anything reasonable that I should request?
I don't want to be hard on the guy, just want to make sure I'm getting a quality job, as I've not seen the process done for about 20 years.
an open blow is pretty straight forward..
here in RI.. my inspector tells me we now have to apply visual depth gages .. my supplier , i think, sells these as plastic tapes that you staple or stick the to the side of the ceiling joists / trusses.. they are marked in inches so anyone can see how deep the insulation is..
if you know the area of the attic.. you can ask the installer for a bag count..the weight per bag x # of bags = total lbs / area = lbs/sf.. no matter how deep , or fluffed.. the tested settled density is printed on the bag..
i think Nu-Wool is a fiberglass , isn't it ?
never mind... i googled Nu-Wool.... looks like a very good cellulose mfr. with supposedly trained installers pushing their product...
you've been to their site , right ?
http://www.nuwool.com/
Mike Smith Rhode Island : Design / Build / Repair / Restore
Edited 1/28/2004 3:33:25 PM ET by Mike Smith
No, it's cellulose:
http://www.nuwool.com/default.asp
After I talked to this guy, the Applegate Regional Rep returned my call. Said he's targeting my area, looking for installers. I had quite a time finding an installer with any belief at all in cells over FG.
I think I'll climb up there tonite and make a few marks on the trusses...just to keep him honest.
Edited 1/28/2004 3:35:00 PM ET by johnnyd
johnny.... any experienced installer can fluff his product.... that's why the bag count and weight per sf is the ultimate measurement..most installers will not think twice of giving you a bag count if you ask for one.. and keep one of the bags for your records... it has all of the information printed on it to be an informed consumer
the other thing to look for is what he will do at the eaves... is your attic vented ?
if the soffits are vented then he's got to run Propa-vents above the highest point of the new insulation and block the eaves so the Nu-wool won't fall into the soffitsMike Smith Rhode Island : Design / Build / Repair / Restore
Got the vents in...I'll get a bag count.
Thanks.
naturally... you wanna get this w/o appearing to be an a-h*ole..
one way i approach it is...." hey.. i'm keeping a lot of records on heating for this house.. so , i'd like you to give me a bag count at the end of the job"...
if he's worth his salt, he may even be flattered that someone caresMike Smith Rhode Island : Design / Build / Repair / Restore
Hey.... I'm a HO GC DIYr...learned early on how to not be an a-h*ole.
really ?..... then share some of your secrets with me... i'm world class... people can't understand why my wife stays married to me....
din't you ever see that button...
"suddenly i realized... i'm a man,
i'm SUPPOSED to be an A$$hole"
helen said i sould stop wearing it.. it only confirmed what people already suspected
Mike Smith Rhode Island : Design / Build / Repair / Restore
Their website at http://www.nuwool.com/ says it is a spray-in-place cellulose insulation.
r:whoops I should have said the glue( how did the glue hold0
Thanks r
He means that most followers of Breaktime have undergone a religious conversion to cellulose from fiberglass. Argument for cells is that it has better thermal performance at low temperatures where as 'glass has degraded performance because of the internal convection loops that form with high temperature differentials. Cellulose is reportedly a superior fire barrier. Many are adherents to the desirability of foamed insulation for its sealing and strengthening qualities, although it can be much more expensive.
If you do stay with fg batts:
Yes, use unfaced batts with a poly vb.
The unfaced batts are designed to "friction fit" in the framing bays and not sag. Be carefule with the installation, try to get each side of the batt in contact with each side of the framing bay. You don't want any channels that air can flow through.
Then run the poly over the framing. Staple it up and run a bead of caulk around the edges/overlaps to seal.
On the walls and ceilings, SCREW the drywall to the framing. I've also heard stories of drywall falling off ceilings/walls, but it's due to trying to use drywall adhesive only over a poly vb...and that ain't gonna work. If it truly was condensation-related failure that caused the ceiling to fall, then there were a lot more problems then just selecting cells/fg/poly.
Thanks for the advise. I will do some looking into the cells especially if I can rent the equipment and do the work myself. If I do go with cells, should I install a vb or does the product act a barrier itself?