I just spoke to a contractor who proposed insulating the hollow walls of my house with blow-in cellulose insulation made from recycled newspaper. Does this stuff work? Is it safe? Is there a better blow-in product?
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Zolo,
I'll try to answer your question but it's far too complex for a simple answer.. For example where do you live, (what part of the country) Here in Minnesota blown in insulation is done all of the time (but it's not the best) it is cheaper and slightly better than fiberglass.. (only slightly)
The problem is that most insulations lose R value when the temp drops and they really lose R value if they get damp (or wet) The only one that isn't affected is foam but foam is far more expensive..
Thus if you arein the humid south for example celluse isn't advised unless you add a vapor barrier. (that basically means you tear off all the sheet rock insulaTe and then add a vapor barrier). nah! the paints ain't worth your time...
If you are in the dry southwest then blown in insulation will be just fine.
zolo... cellulose insulation is great... it's fireproof... better insulation than fiberglass... and contrary to what frenchy continues to say.. it is NOT susceptible to moisture in the AIR
what a bunch of crap...
this from the man who's pouring peanuts in his block wallMike Smith Rhode Island : Design / Build / Repair / Restore
Mike,
To correct your many mistakes. First I said it was better than Fiberglas, go ahead have someone read that part to you.. Then I said that, if it gets wet nothing about air. Note I mentioned vapor barriers!
I didn't mention fireproof because sure it is (unless it gets wet and the fireproofing leeches out) even then it's highly unlikely to be the source of fire since in the rare occasion when that would happen wet cellulose isn't going to burn anyway!
Nor did I mention the rare occasion when it gets damp and moldy and cause wood to decay because the problem isn't really the cellulose but whatever allows the the moisture to keep coming in..
Finally if you reread what I said I'm not pouring peanuts I'm pouring granules.
oh, really ?.... you said nothing about the humid south ?
and " slightly better"... hah, hah, hah.... gimme a break
grannules, peanuts... potatoes, pahtahtoes
you are one smart dude when it comes to job site material handling equipment.. but your building technology background is slightly limited..
oh, yeah... your politics ain't bad , neither...so , i guess i still love you..
hugsMike Smith Rhode Island : Design / Build / Repair / Restore
Mike,
We have a problem with insulation.. I am trying to convince you that Fine Home Building is right when they say that wet or damp cellulose has poor or no insulation properties and you insist that dampness doesn't affect it..
I'll be fair, pour a cup of wayer in the next handful of insulation you install and see how well it insulates.. Now to be fair you'd have to do a labratory test and that really is too much to expect, lose plus I think you will agree with me on that score.. Now the only issue left is if moisture can be absorbed from air..
I think we agree that every home should have a complete vapor barrier. That would remove a major source of moisture from getting into the insulation.. I'll also conceed that exterior water should be kept out.
The sole remaining issue is can the moisture in the atmosphere reduce the effectiveness of insulation..
Every article I've ever read about cellulose has it's effectiveness tested under labratory conditions.. so what are the real world numbers.. I frankly don't know and if you have a source I'd be interested in reading it.. Unbiased please!
Simple logic lends me to believe that the moisture in air will be absorbed by cellulose. Wood absorbs moisture from the air and swells under humid conditions..
By what logic do you feel that ground up paper wouldn't do the same? Paper is made from wood, wood absorbs moisture from the atmosphere (air) paper absorbs moisture from the atmosphere, why would ground up paper treated for fire prevention not absorb moisture?
By extension then the real world effectiveness of cellulose should be reduced in the presense of moisture.. That's why it's always tested under labratory conditions.
Finally I'm an advocate for SIPs because they solve the other issue of cellulose insultion that concerns me, mainly the transmission of cold into warm rooms (or more properly warm into the outside cold) through the low insulation value of studs.. those 2x4's or 2x6's with an R value of 2 that are every 16 inches and often doubled or tripled up for strength reasons.. That inch and a half or 3 or 4 & 1/2 times their length means the very best that can be achieved in a given wall is 80% of the actual rating numbers..
Last winter I proved it to my satisfaction with a lazer temp detector (a by product from my sportscar racing days) I could easily find every stud in my wall because it was 4 degrees colder than the wall protected by insulation.. No place in the SIP's portion of the house varied one degree. The ceiling 28 feet up nor the floor varied one single degree Now had I had a sensor calibrated in hundreths of a degree I probably would have detected a slight change where the thru bolts tied the innner timbers to the outer timbers but since we are talking about 1/2 diameter bolts inside 6/10/ 12 inch timbers. passing thru 6 1/2 inches of foam (11 1/2 on the roof) it would take an extremely accurite detector to note any differance..
I'll give you your due, most homes are built with studs. It's faster and cheaper so it will continue, cellulose is better than fiberglas and sprayed foam is more costly then cellulose. Since cost is a major factor in home purchase you will be the major player for a long time.. I don't see a point in the near future where you'll ever have to worry about job security..
Yet in my reaserch I found nothing superior to heat retention than SIP's (other than exotic stuff with no track record..) I'll continue to advocate for SIP's and you continue to support the cost effectiveness of cellulose..
Oh, and by the way I'm sorry for the cheap shot in my last post..
Edited 8/9/2005 6:42 pm ET by frenchy
Frenchy, why are you always harping about wet insulation?
Dense pac cells aren't going to absorb enough moisture from the air to get wet. I have no water dripping from my ceiling, the bottom of my blower hasn't rusted out yet although it sits with cells left in it.
The guy didn't ask about SIPs, so what you are using to build your house isn't helping his situation, is it?
*dense pack needs to be installed by a pro with experiance because it is possible to over fill the cavity and reduce the thermal effectiveness of it.
Gotta admit that's a new one. Something you read about, or made up on the spot?
Simple logic lends me to believe that the moisture in air will be absorbed by cellulose.
Your logic may lead you there, but experience tells me otherwise. Seems I'd have heard something about the class action lawsuits filed to cover the damage to millions of homes with drywall failing due to wet cellulose.
Again, have you installed cellulose? Have you owned a house with cellulose that absorbed so much atmospheric moisture it oozed out from behind the baseboards?
Joe H
joe... frenchy had some wet cellulose in his attic of the existing house.. somehow or other he has decided that it got wet by absorbing moisture from the air..
he has extrapolated that discovery ( wet cellulose ) to all cellulose absorbs moisture from the air unless you live in the desert....
oh, well... i just don't know how i will muddle onMike Smith Rhode Island : Design / Build / Repair / Restore
Wet attic from huge air leaks from downstairs turning to ice on the sheathing and dripping into the insulation?
Definitely blame the cellulose, FG wouldn't have done that.
Seems I remember reading some horror stories years back about SIP buildings in Alaska (?) that hadn't been assembled correctly or some kind of builder error that had big problems with water getting in and causing the OSB to mold and disentegrate. Water doesn't belong under a roof, outside only.
I bought some cellulose that had been out in the snow this winter. Turned to stone where it had been wet. My machine didn't like it, kept plugging the blower inlet. No mold though, just lumps in the gravy.
Joe H
JoeH
You and I agree that proper assembly of SIP's is important and that if you expose the OSB to a steady exposure to water it will fail miserably. I guess any system that exposes any OSB to a steady diet of water will fail just as miserably..
I've never been an advocate for Fiberglas, It wouldn't perform well at all exposed to moisture. I think of the three common insulation materials out there it is by far the worst..
Your comment about your Cellulose that had gotten wet intrigues me. My cellulose got soaking wet every winter and yet by summer was as dry and fluffy as if nothing had ever happened.. is it just the packed unblown cellulose that has that characteristic?
Mike,
If you could explain why wood will absorb moisture from the atmosphere and why paper wouldn't I will no longer raise any objections to cellulose and remain quiet on the subject..
Second, break open your thermos bottle and if you find cellulose in it,... Tell me the cooler that you haul your drinks in on a warm day, is that made from cellulose?
Aw this is too much fun!
Mike you have a very good point.. cellulose is cost effective and under certain conditions works very well.. Foam has it's short comings as well, in that it isn't the cheapest, nor is it easy to DIY.
OK, I'm going to try to explain why Mike's homes work, and why Frenchy shouldn't be so worried.
Yes, Cellulose can absorb moisture (and allow vapor diffusion through it). Yes, if warm, moist air from within the house could migrate to the cold vented attic, vapor will condense within the cellulose and soak it.
However, Frenchy is worried that moist air coming in the attic vents might condense inside the attic. This can't happen in cold climates in heating season. The whole attic and attic insulation is always slightly warmer than the air venting the attic. Therefore, no condensation can occur because all these surfaces are always warmer than the dewpoint of the venting air.
The Building Science guidelines explain what happens in walls, but it takes a while to understand.... http://www.buildingscience.com/resources/walls/insulation_sheathings.pdf
To summarize B.S. you must keep the "Air Transport" to a minimum (we used to call this infiltration). Dense packed cellulose naturally prevents all air transport without any other sort of air infiltration barrier. Cellulose cannot prevent diffusion, but the Building Science info. explains that diffusion is negligible. Any condensation from diffusion will evaporate back out of the wall (or attic) quickly. The diffusion barriers are never perfect, so the vapor can get back out to the outside or inside also by diffusion.
In a hot, humid climate, the analysis is different. Mike builds in the Northeast.
"He's not a real doctor" "I.... have a Master's Degree..... in........ Thermal Science!!"
JoeH
Wet insulation can have a dramatic effect on the effectiveness of most insulations (foam is exempt) It's been well discussed in the pages of Fine Home Building..
Yes I owned a house with cellulose that in the winter absorbed so much moisture it turned sodden and only dried out when the heat of summer hit it.. The result was $500.00 per month heating bills
I never found any leak to attribute the moisture absorbtion from. Either thru a failed vapor barrier or any track/ mark trail of a leaking roof.. There were vent holes and it is normal to get extremely damp weather here in the fall prior to the onset of winter.
I know that the wood swells up prior just to the onset of the heating season so it is reasonable to believe that ground up paper would do the same..
As for your contention that your blower should fail thru rust thru if cellulose absorbed moisture, I would hope that it doesn't sit unused year after year. To be fair the cellulose in my attic was never wet or damp in July or August thru the heat of the summer so at some point the cellulose completely dried out. I know this is slim evidence but I did notice as I took the house apart that every nail covered with the cellulose was well rusted while all the nails above the cellulose were still shiney and pulled out easily..
Finally it is true that he didn't ask about SIP's but since the insulation I chose was foam I thought it might be usefull to give some actual numbers to the relative efficency of each system in actual use. At one time (last year I was in the unique position of having all three insulation systems in use in my home)..
Frenchy, you are applying the problem in your attic to the entire world.
Using your logic, every house in the country with cellulose insulation has a wet mess in the attic.
It just ain't so.
Joe H
Hi, this thread caught my eye because we need some blown-in insulation. We bought an old (as in 1904) church, 70 x 25, with approx 12' walls to a 12/12 pitch roof. Inside the ceiling follows the rafters up to a 14' long collar tie at which point the ceiling is flat inside. Above that ceiling it's an open attic 14' wide at the base and about 7' clear standup height. So inside there is about a 20' ceiling height (it's really one large sanctuary room). It's all frame - lots of long pieces of fir in there which we could scarcely afford today... The walls are 2x6 plaster and lathe with some sheetrock inside over that. Outside is crappy stucco over cedar shakes. The roof is 2x8, with fir beadboard (3/4" T&G, 3-1/4" face exposure) on the inside, and cedar shakes and one layer of FG shingles on top of that.
There is ZERO insulation anywhere in this building (yes, the mind boggles). We looked in the Yellow Pages under "Insulation Contractors" and started calling people. We told the contractors they could drill as many access holes in the wall as needed. There's clear access from the attic into the ceiling and roof cavities. We are in Salt Lake City Utah so it's relatively dry (17% RH at 88F on Sunday). There's no vapor barrier in the building that we know of and the only one we can easily add is interior paint. So far in the little poking around we've done, the walls etc look dry.
The local cellulose guys said they would not bid on a blow into 2x6 walls due to the "plaster/lathe ooze through getting in the way of good penetration". The next guys said they would strongly recommend blown in fiberglass because it doesn't settle as much, is the same cost as cellulose, and is inherently fire resistant. They also said OSHA recently changed their rules so that their workers are no longer required to use a respirator with blown in fiberglass, so it's considered "safe".
No one suggested foam to us. Should we consider it at least in the exterior walls?
So now we are wondering what to think...
Another related question is whether we try to strip and varnish/urethane the fir beadboard ceiling. At the moment it's under acoustic tiled stapled to firring, which is over painted canvas (yes, canvas). We cut open a couple of areas and the beadboard looks like it has a single layer of grayish paint, and we plan to test some stripper on it. It would be a lot of work, but man it would have to look great to have a natural wood ceiling. Otherwise it's sheetrock over the existing firring, I guess. Maybe a vapor barrier up first, over the firring, then the sheetrock (5/8?). Or some foam board insulation first?
Thanks
Bruce
I just got into this discussion and found it very informational. I have been going around in my head for my new home on this subject. I intially though SIP's but gave up for two reasons 1) doing the wiring and plumbing 2) the possibility of wet OSB. I looked into foam and the costs extimated were out of this world. One was at $5.00 /sf but best was at about $1.25/sf. Cellouse was looknig good but I did not have current experience from anyone except the supplier. All of your comments were really helpfull and now I will feel comfortable using cellouse. I'm in So. Cal so mosture is not a problem except leaks. I will be doing the GC jpb and much of the work so inspections for it being right is up to me. On my last house remodel ( courtesy of the '94 quake) I spent about one day fixing the new fg after the contractor left.
Thanks to all
Bill70
Bill70
Let me settle a few issue for you about SIP's In southern California they are probably much better insulation than you need.. energy costs are low out there and it's a lot cheaper to build a poorly insulated house than spend all that money on insulation. I don't know much about keeping a house cool in the hot Calfornia weather but again I'm sure that if you buy something cheaper you'll always be happy.. Heck, do you really need insulation at all? ;-)
OK enough sarcasim.. Sorry..
Wiring with SIP's is just as easy as wiring w/ stick built house, easier! .. The trouble is few people actually have done it so there is this great big fear thing.. SIP's or ICF's are really less than 1% of the houses built. Thus darn few people have any real world experiance and according to rummor electricains can be swollowed up by a SIP.. Oops there's that sarcasim thing again..
Heck when you order your panels you tell them where you want the wire chases and they come that way.. Make a mistake and forget something? Well they sell these cheap spade bits that eat thru foam .like , well a spade bit eating foam.. try this,... yourself get a coffee cup made of foam and drill a hole in it. use a dull toothpick if you want any challenge.. now try to drill that same dull toothpick thru a 2x4..
Got a long run?!!! Buy a whole bunch of extensions.. They are cheap!
As for plumbing!
Well you need bigger spade bits but I can always run my plumbing thru inner walls, or up thru the basement..
Frankly I would give up a little of the insulational value of SIP's in Calfornia and build with ICF's I think it would be cheaper! Around here they get a 2% premium for ICF's over stick built but the gains in strength are easily worth it! Not to mention the gains ICF's have in energy savings compared to stick built..
It would be relatively easy to make a Home Tornado proof (or earthquake proof) with either SIP's or ICF's. Stick built needs a lot of Simpson connectors and a lot of extra wood.. then it's extremely iffy!
One final arguement, On a stick built home every 16 inches on center there is a thermal bridge.. What is the R rating of a 2x6? or worse a 2x4? maybe 2? now count the places where they are doubled up or even more. At best on a straight wall with no windows you actaully have 80% of the stated ratings and often it's less than 50% With either a SIP or an ICF you have 100% unaffected by moisture or settling..
Thanks for the comments. I seem to have this old fashioned way of wiring stuck in my head-flex conduit. As this will be my house there will by an excess of breakers and outlets. I have looked at new home tracks and the romex wiring looks like a birds nest of string. I could not follow most of the wires and the bundles were huge, and this for just a track house. We are still not allowed pex plumbing in calif to the latest of my knowledge ( plumbers union I think) so will be going to proven old standby copper. I read an article in one mag that the contractor stated that he just routed grooves in the inside osb where he wanted the elect lines. I read that and thought " that must help the shear strength a lot!". I actually am going to steel construction with 8" walls through Ti Steel ,If they can ever get their act together, for my shop. For the house I have given up on them (been waiting 14 months) and will use another steel technology and use 6" single or double 4" walls. Steel gives another problem, according the the energy engineer I have a lot of energy transfer through the steel studs so still must use a 1" sheet foam on the outside anyway.
So much for my problems but thanks for all of the suggestions.
Bill
Bill70
I'll admit that sweating copper inside a foam wall would be pretty tough. On the other hand I use PVC and simply the glue the length of pipe together.. But never on an outside wall, too often in my climate things freeze when too close to an outside wall and it's 40 below.. but that doesn't happen too often in Calfornia I hear. ;-) Since I don't use my outside walls as plumbing chases it's real simple to arrange the plumbing to an interior wall where normal plumbing practices work. Inner walls can be made of steel or studs because you aren't using those walls as insulation. This is one spot you could use cellulose or fiberglas if you wanted to.. I mean both deaden sound and that's all that is achieved when insulation is used on inner walls..
As for shear strength, as an engineer you must be aware that SIP's have something like 200% more shear strength than a stick built wall.. think of it.. any stick built wall is held together by the strength of it's fasteners.. in steel it's those little screws and in stick built it's the nails.. sure there are a whole lot of them so any one nail/screw doesn't carry the whole load, but when the load is equally distributed over the whole panel as it is in a SIP reststance to shear isn't much affected by a single cut..
would you like proof?
Buy a SIP panel (or stop by my place and get my cutoffs for free) ) and jump up and down on it in a way that will destroy any stick built panel.
Does your plumbers idea weaken a SIP somewhat? Sure a bit, but think of the countless brutalizations done to the joists or studs of a stick built home by the HVAC guys.. Now tell me how could you possibly live in a home so butchered?
Finally regarding the wiring issue. My home is getting near the finish line and I have only put a few pieces of armourflex into the panel so far.. Only a few basic plumbing lines are thus far run.. I actually only had to put three circuits into the panels in a house of over 4000 sq.ft. The first is the wiring in the great room lighting up the ceiling, the second is for a light over the billard table in the billard room, and the third was a double switch used for the kitchen. I have run several circuits under timbers in my house, but I used a Mikita Groove cutter to run those and they are well hidden.
Bill70,
SIPs shouldn't be ruled out because of moisture. The problems in Juneau were obvious and easily prevented with decent installation details. Remember, with SIPs there can never be moisture inside the wall, which is where most mold problems arise.
If I were building in Cal., I'd use SIPs just for their earthquake performance. There is nothing better, including reinforced concrete. F=ma which means that a wall that is 5 times heavier, needs to be at least 5 times stronger.
Thanks for the information. I had orginally designed my house with an architect for SIP's but after talking with an engineer and others I shyed away from it. I saw a great steel home and decided to go that way. I just felt more comfortable with the construction.
Bill
Contractor "S" just called back and we had an interesting chat. They don't blow in FG into existing cavities anymore - said the glass strands tend to catch on things and you wind up with voids, whereas you can get 100% penetration with cellulose.
They also won't foam into a closed cavity since the foam sets up too quickly to let it flow around all obstacles, corners, etc, so again you have voids.
They do foam in 1" to 2" where there is an open cavity, since foam is R7 per inch, then put unfaced batts or cellulose on top of the foam.
So we are discussing having them foam 1-2" in the flat portion of our ceiling (70 x 14 feet) then blow cellulose on top of that.
They are also going to reconsider blowing cellulose into the walls. Their concern was that drilling access holes into just plaster and lathe would damage the walls too much (having installed some outlet boxes etc in P&L I can understand this concern). But since in our case there is sheetrock over all P&L surfaces we don't care if the P&L layer in the walls gets "damaged" by the hole saw.
I asked if they call their cellulose "dense pack". (This is the #1 cellulose contractor in the area and they were recommended by several contractors etc.) He said they don't use that term exactly but that he would consider it a dense blow in - the cellulose gets packed in around pipes, etc and has a very low void issue.
Update a couple of hours later: the concern with hole drilling turns out to be worries about wire mesh lath! So if we can confirm there is no mesh, or drill our own holes, they will blow in cellulose no problem. My house (1908) has no wire mesh, rather it uses horsehair in the plaster, over wood lath, but apparently in the late 1800s metal lath was coming into favor, since it makes the wall more stable than wood lath. For example: http://www.bobvila.com/ArticleLibrary/Task/Repairing/ThreeCoatPlaster.html
Maybe in our buildings they were just cheap, or maybe metal lath just wasn't popular in Utah at this time. In any case we have wood lath which is relatively easy to drill so I guess cellulose it is.
Bruce
Edited 8/16/2005 3:39 pm ET by BruceBoyes
Bruce, I've spent enough time in SLC (months) to know that radiant heat gain in the summer is a big issue. Cellulose is opaque to radiant wavelengths, while FG allows them through. Go with the cellulose and foam. And if you've got any spare time, have breakfast at the Park Cafe or dinner at Ruth's Diner for me.
AndyAndy Engel
Senior editor, Fine Woodworking magazine
An updated profile is a happy profile.
Other people can talk about how to expand the destiny of mankind. I just want to talk about how to fix a motorcycle. I think that what I have to say has more lasting value. --Robert M. Pirsig
None of this matters in geological time.
We had no idea about that - thanks!
The Park is just a couple of blocks from my house and this old church/future office space... my favorite local place is the Desert Edge brewery in Trolley Square. They make their own beer - and pasta - there and the patio is very nice this time of year. If you are ever back in SLC give us a call and we'll take you there...
Trolley Square isn't far from where my wife used to live - Windsor Street. If memory serves, that was something like 1140 East, maybe 13th South. SLC is one of my favorite places, and somewhere we're considering for just a little later in life.
Next time I'm out there, I'll look you up. Have you walked around the models of the canyons in Liberty Park? That's one of the coolest things I've seen anywhere. Ironically, the first place that I ever had what I'll snobbishly call a good cup of coffee was in SLC, at The Roasting Company.
AndyAndy Engel
Senior editor, Fine Woodworking magazine
An updated profile is a happy profile.
Other people can talk about how to expand the destiny of mankind. I just want to talk about how to fix a motorcycle. I think that what I have to say has more lasting value. --Robert M. Pirsig
None of this matters in geological time.
Yes, Trolley Square is between 600E and 700E and 500S and 600S.
The Canyons model, with flowing water, in Liberty Park is a favorite of my kids. For those of you not from the area, it is basically a (roughly 100' x 20') scale model of the mountains to the east with their multiple canyons, and water flowing in each one, all draining into a 12" deep 'lake'. It was not designed originally to have kids wading in it (doh!) and there were problems with bacterial contamination from all the kids doing just that. So they shut it down for a year and added pool-type filtration. It's back in operation now. Also there is a very cool new area designed as a play area with handicapped-accessible centers - like swings that hold you in with a harness. Here's a link with a photo - scroll down to Liberty Park: http://saltlakecity.babyzone.com/parentresources.asp?type=Family+Fun%3A+Parks+%26+Playgrounds
That opened in 2002 and is a fantastic area, it's in the NW area of the park. It has a series of fountains operated with a rotating ball on a pedestal. The fountains spray up from an area made from recycle rubber. It's really a hoot to watch kids playing on. Also the swimming pool there has been refurbed and has a large shallow area for young kids. I just got back from there moments ago where my 3-year-old son had a swimming lesson.
Bruce, Mountain Fiber in Hyrum makes cells, you might give them a call if you're still thinking.
They should be able to provide some names for you.
Joe H
Thanks, here is the Mt Fiber cellulose website: http://www.mtfiberinsulation.com/ -- I filled out their online request form.
So this begs the question - could we save some moolah by blowing this insulation in ourselves vs hiring a contractor? Fools rush in where angels fear to tread, and we're acting as the general contractor on this job, so we're willing to tackle this, and it would let us do the job piecemeal, where a contractor will want to do it in one bang.
Bruce
If you haven't made up your mind yet consider 1/2 lb open-cell foam.
I install Icynene but there are others on the market .and there is a slow expanding version that would do what you are looking to do. drill small 1/4 in holes every 2 to 4 feet up the cavity and install the foam, it takes several minutes to expand slowly filling the cavity space leaving no voids ( this does require a contractor who knows what he/she is doing) after it rises and comes out the hole then you move up to the next hole, continuing up the wall Intel you reach the top. this is a slow process but it will do what you are trying to do. and to finish it off you spackle the hole over. then paint and done.
also the mesh no mesh should not be a problem to a good contractor that knows what he is doing. cant say that enough you need a contractor that understands his product and the building science behind it and how to install it into any application he is confronted with. I'm not saying anything against the contractors you spoke with.
BUT being the most recommended doesn't mean you know the building science behind what you install. Sometimes your the biggest company because your the cheapest. on the same token because your bid comes in high that doesn't mean that contractor has a clue either he jest charges moor and the uneducated consumer keeps them in business. time to get off my soap box.
and so you have something to compare with (I know being from a deferent area the prices will vary but.) Foam 1/2 lb should be in the $.35 to .50 cent range per board foot. this is not set in stone and changes from area to area ( don't hold me to it) and now with the new gas prices?? enough said!
If you need help finding more information contact me I will do what I can.
Good luck on your project.
Yes I'd like to discuss this more with you. We cannot find anyone here who installs foam into existing closed cavities (I called every foam insulation number in the yellow pages). The ones who did buildings at all (as opposed to pipes in a refinery, or cold storage lockers) only do foam as a sprayed in layer 1" to 2" thick, then topped with unfaced FG batts or cellulose, and this is only into a cavity with one large open side (like before putting siding on), so it's no good to us with existing 100-year-old walls already finished on both sides. Your technique sounds interesting since
it would never settle,
the holes would be small (1/4" vs 3"-4" dia)
later if we remove the existing siding (5 years down the road), the insulation won't fall out
What about fire resistance, borate for insects, etc?
Anyone you can recommend in Salt Lake City?
Thanks
Bruce
JoeH,
Please show me the error of my thinking..
The R rating given to cellulose is based on labratory conditions.. That means the cellulose is dry as toast and free from any moisture..
The real world has moisture, particlarly in the rainy fall. Most attics need to be vented thus most attics are exposed to moisture.. It is my contention that the cellulose will absorb moisture that is in the air and in doing so will reduce it's real world performance numbers..
I accept that every location would be differant and a home here on a rainy week could have a pretty high moisture content. If that moisture happened just prior to freeze up how would the cellulose ever get rid of that moisture? However a home (for example) in the southwest would have only a tiny bit of differance betweeen the numbers quoted and the real world..
Every locatiuon would be differant and an attic that was supposed to be an R50 might actually test at R 35 or R15 depending on how much moisture was absorbed..
Frenchy, your experience with one house does not make it so.
Cells work, they don't turn to mulch in attics and drip cellulose soup down below.
There are enough people telling you otherwise, why don't you just believe it unless you can prove otherwise?
Prove = more than one example.
Joe H
JoeH
Fair point, other than my own house I've only actually seen the existance of soggy cellulose once (my sisters house) I actaully have seen damp fiberglas several times so fair is fair..
To be sure not everyone invites me into their attic.
Now that I've answered your question would you please answer the same question I've repeated several times?
To refresh your memory,....
Why will wood absorb moisture from the air but the paper that makes up cellulose not do the same? Aren't attics supposed to be vented and doesn't that venting allow whatver moisture there is in the air get into the attic and ultimately into the cellulose?
Your R rating of cellulose is based on labratory conditions, as you increase the moisture of the cellulose doesn't the cellulose lose R value?
Frenchy, using your "There's moisture in the air, it's gonna make the cellulose soggy" theory, could you please explain to me why everything in your house isn't also soggy?
Is there flour in your cupboard? Has it turned to wallpaper paste?
Do your books drip on your lap when you read in the winter?
Is the toilet paper as wet on the roll as it is in the john?
Wet insulation caused by condensation on cold attic surfaces, or a leaky roof is one thing, insulation that wet strictly from localized humidity conditions would probably indicate that cells are not the ideal product for that environment.
Where that place might be, I don't know. Belize maybe?
Joe H
JoeH
Well it does happen, that is in the salt shakers gets all clumpy so we need to add several rice kernals or the salt in the shakers clumps up to the point where no salt gets out. We need to keep things in tupperware or they do turn soggy. I'm right now eating soggy salted in the shell peanuts because last night I fell asleep before I put them away..
Humidity is rather high and I live right on a lake so the problems get worse with 300 million gallons of water about 90 feet from my front door.. I could reduce the problem by running dehumidiers but with the east wall wide open I doubt I have a big enough one ;-)
A/C also dries things out but the idea of closing everything up just to dry things out doesn't really excite me..
This is normal and when I lived in San Diego I lived on the beach so it was pretty humid there as well. I don't know where you live but perhaps your not as exposed to moisture there as I am here..
" The R rating given to cellulose is based on labratory conditions.. That means the cellulose is dry as toast and free from any moisture.."No, it is not based on "laboratory conditions". Rather is based on very specific conditions.Now I have not seen the test proceedure, but I doubt that it uses the term "dry as toast". Rather it will have specific moisture value and testing conditons." If that moisture happened just prior to freeze up how would the cellulose ever get rid of that moisture? "First you don't have any idea about the difference between moisture and water (or free and bound water).But assuming that you statment was true, ever hear of SUBLIMATION?
BillHartman,
here we disagree. I wasn't being literal regarding the comment dry as toast. but I have no doubt that since the R rating of cellulose is dependant on the moisture content it's dry as a popcorn fart,.. ;-) when tested..
Yes I used the term moisture and water fairly interchangeably and no they aren't exactly the same but they are pretty interchangeable except for those who insist on being anal..
In any case take a cup of H2O and dump it on a handful of cellulose and tell me about the resultant mess's thermal conductivity properties.
Fine Home Building has repeatedly said that damp or wet cellulose (or Fiberglas) loses insulation capabilities. I hope that isn't a challenging statement. It is well documented about the ability of wood to absorb moisture from the air (I think the wood is hygroscopic) in designing and building furniture and most things made from wood it is well understood and dealt with. We know that cellulose is made from shredded paper and that paper is capable of absorbing moisture so why wouldn't cellulose absorb moisture if it's exposed to the air that arrives via the vents in the attic?
"Yes I used the term moisture and water fairly interchangeably and no they aren't exactly the same but they are pretty interchangeable except for those who insist on being anal.."No, there are a number of significant differences in their charcteristics and phyiscal properties.Try washing your hands with moist air or taking a steam bath in hot water and you see some of the many differences.
" I think we agree that every home should have a complete vapor barrier. "Mike must have missed that one.But I don't agree if you "complete vapor barrier" you mean something like sheet poly.
no.. i don't agree on the vapor barrier... when we used to use FG , we were very careful about sealing with a 6 mil poly vapor barrier..
since we switched to dens-pak cellulose we do not use vapor barriersMike Smith Rhode Island : Design / Build / Repair / Restore
Bill, the theory is dense pack doesn't need a vapor barrier because there is virtually no air flow through the stuff when it's packed tight.
I'm careful to seal small openings with gun foam, the cellulose will plug tiny openings, but bigger ones will let it through, usually eventually plugging but making a hell of a mess sometimes.
It's not perfect, blowing foam will seal up a building better & more R too, but the cost is high and rising. The price of cellulose is low and stable. The price of FG batts is a waste.
Joe H
BillHartman,
You may have something there. I do know that those so called vapor barrier paints aren't worth much and that with sheet poly it is extremely easy to punch additional holes into the sheet and cause leaks but I can't off the top of my head think of any other way (short of spraying a barrier of foam) to get a vapor barrier.
Bill I visit new homes day in and day out for the last 14 plus years & I've never seen anything else done... Maybe I failed to notice something else but I'm courious what you re thinking of..
To be fair to yourself and every other cellulose advocate out there when I tore down the old roof I didn't carefully examine the poly barrier for additional holes. It simply went into the dumpster. I did notice a complete and untorn vapor barrier free from any holes or obvious tracks where moisture could have gotten into the attic. Vent pipes and furnace /water heater exhaust pipes were well sealed up and showed no signs of being the source of vapor....
"" I think we agree that every home should have a complete vapor barrier. ""You said EVERY HOUSE.Not every house is in as cold a climate as you are.In my climate 3 or 4 months of the year (depending on how much you rung the AC) moisture drive would be from the OUTSIDE to the INSIDE. It you put poly on the inside of the studs and depend on it to control moisture movement you would end up with condensation on the backside of the poly and the only place for it to go is to soak the insulation and stud. And down south it is much worse.So expect in the coldest climate some other ways are needed to control the movement of moisture. Ones that will allow the wall to dry out.
BillHartman,
Fair enough, I stand corrected! I failed to think beyond my own environment, not the first time and I'm certain it won't be the last..
>> most insulations lose R value when the temp drops I have seen that said of RG, but not of cellulose.The Cellulose manufacturer's assoc. says it increase in R-value as temps drop, although one must, of course, consider the source.The FG assoc says the opposite, of course!Doing home inspections,I think cellulose has the edge because it is harder to screw up the installation.Although techniques have improved over the years, it is still pretty common to see significantly less than ideal FG batt installations.The other issue is settlement and walls.I usually scan walls in cold weather with a laser thermometer, and I haven't seen any obvious settle issues on any consistent basis, but I suspect my ad hoc testing is less than perfect.(Although it is surprising how often I can find missing sections of
or gaps in FG batts.)
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Bob,
I wish I had access to my library of articles on insulation, many of them from Fine Home Building. I don't right now, the house is apart and the only thing between me and the rain falling is a blue tarp.. The boxes are stuffed away and I won't even attempt to find them.. (maybe this winter)
Anyway the best I remember Foam had the least loss of R value while fiberglas had the highest in cold conditions.. Foam is unaffected by moisture while both fiberglas and cellulose is greatly affected.
Fiberglas had the highest airflow numbers while foam had the lowest..
I agree with you that it is extremely easy to misinstall fiberglas while densepack cellulose* is more forgiving and it's hardest to screw up foam.
* dense pack needs to be installed by a pro with experiance because it is possible to over fill the cavity and reduce the thermal effectiveness of it.
I'm interested in your experiance with SIP's, and foam in general.. during home inspections.
Zolo, what Mike said. We've used it for decades now, with NO issues. (Listen to Mike- he knows what he's talking about.)
everything you always wanted to know about cellulose:
search archives for thread 39075.1
Thirty years ago, we had an uninsulated house in San Jose, CA. The place was always chilly in the winter and an oven all summer.
One hot summer day, a door-to-door insulation salesman stopped by and - since I was bored out of my mind - I listened to his pitch. He was selling blown-in, recycled newspaper, insulation and I was ready to send him down the street when he offered to demonstrate the fire proof quality of the stuff. He picked a handfull out of a bag, fired up a propane torch, and stood there talking for a minute or so with the torch aimed at the wad of insulation.
It charred a little, but was only slightly warm when he handed it to me. That sold me! We couldn't afford to blow the walls, but 6" blown into the attic sure made the house more comfortable - and substantially lowered our utility bills too.
Zolo, cellulose is great stuff. More R for the buck than any other product.
If you dense pack the walls you will have a much better job than any fiberglass batt.
It's safe, it works.
Ignore Frenchy, he's been spewing this gibberish about wet cells for years with (as far as I know) absolutely ZERO experience installing the product he knows so much about. That is zero, as in he has never done it.
Joe H
Zolo:
Last year we had a timber frame cape built with a stick-built ell. The t-f used SIP insulation, while the ell had blown-in cellulose (More-Tite, Jaffrey, NH 603-532-4594). The house had no noticeable drafts last winter in NH. The blown-in technology seems appropriate for stick built and musch better than fiberglass batts (sp?).
Consider the building envelope and moisture transmission; ensure that all openings are sealed; and ask about insect and fire-retardant features before the installation.
the blown-in cellulose insulation is treated with borate and if I remember right, that's what gives it the fire-resistive capability. the insulation value is similar to fiberglass but can "drop" as the cellulose settles. the other major consideration is if you have knob and tube wiring - last I knew, it was illegal to use blown-in cellulose if there's knob & tube present since the blown-in insulation doesn't allow the old wire to "cool" (?) and it can fail and eventually cause a fire.
Ok I'll add my 1 cent worth.
In 21 years as a firefighter I have only seen 2 fires that involved cellulose.
The first one was Hot I mean Hot! It just kept the Heat in period!I did not see any spread of the fire do to the insulation.What I did see was charing of the insulation and fire where the wood frame members were(2x4,2x6 etc)I'm a simple guy ,if it kept the heat in,it will keep the cold out.
Second one was about 1 1/2 months ago 2 1/2 story cape,fire was in the attic.It seems that someone jury rigged some knob and tube wiring into some new romex,and several air conditioners were running (drawing a lot of juice)The wires over heated.I'll take a wild guess and say that maybe some 12 gauge and 14 gauge were mixed up or that the a/c s exceeded the amp rating of the wires.The fire was smoldering all night.
What I saw being one of the first ones up there was that the floor boards and structual members were burning especially in between the gaps of the floor boards as this was an older house.When I smashed the floor boards with a tool the fire started to take off ,thats when we hit it with the hose.The only damage to the cellulose was charring ,some of it was a couple of inches deep,but keep in mind that this fire was smoldering all night.
I have been fires where fiberglass was installed and I'm not impressed.The tar & paper backing (or petrolium based) seems to help the spread of fire.Batts with out paper seem ok.
In my area ,CT wet spray was popular a few years ago,not now.The company I had a contract with moved out of town.too many law suites with the damp spray( too much moisture in the walls.)
Dense pack is another story,I checked a house out the other day with dense pack and all I can say is wow!I'm putting it in my new house.
Mike S can they do dense pack in this guys house ?
Greg
Lead,Follow,or Get the Hell Out of the Way!
look up foam insulation on the web it can be added to the walls with out removing them. you will need to paint the walls but you wont need to replace them to get it in the wall cavity. ( similar to cellulose) the difference is foam wont let air move inside the cavity. (this is called convection heat transfer)
Also remember R-value is calculated in a lab and they don't take into account wind. foam is the only product that (if installed properly) can stop air movement through a wall cavity. dense paced cellulose is a close second.So if you are price shopping go with the cellulose but if you are looking for a long term investment in your home then look into foam.
FoamMan, I assume you're referring to FG when it comes to convective currents in the wall cavity? I used foam throughout my house because I needed a higher R-value than I could get from cellulose in the thin walls we're "blessed" with, but when you have the luxury of thick walls to play with, dense-pack cellulose is a great, draft-free insulating material.
Yes I was referring to FG. but I was also including regular cellulose not the dense-packed cellulose
Hey, don't you have a mirror and backsplash to install, get to work!!
If it's not dense packed, it will settle to the bottom of the cavity and there will be zero insulation in the top portion.
Yes I was referring to FG. but I was also including regular cellulose not the dense-packed cellulose
Is this a fair comparison? Would you spray only the lower half of a cavity?
There is no noticeable air movement through dense pack cells.
Joe H
Edited 8/10/2005 4:01 pm ET by JoeH
Guardian Industries manufactures a blow in fiberglass. you might want to investigate it. My experience has been great.