Batts vs Blown-In

[rwreuter]

which is cheaper for attic insulation over the garage: 750 sq ft ceiling

purchase 24" 2x6 unfaced batts


or


buy insulation and use lowes or home depots free blower

 

[phbsales]

You get a better insulation job using batts. It's hard to get the right mixture of air and material for the blown-in stuff, let alone accurate coverage in the space.

 

[MichMan517]

Not sure which is cheaper, that would be up to you to find out, but I agree that batts would be your better choice. I just did my 530 sf garage attic with 24"x6" fiberglass, in 2 layers, the 2nd being perpendicular to the lower layer. I hope to reap the benefits this winter in SE Michigan.

 

[ratdoggy]

For a garage with no living space above would you need a vapor barrier or just unfaced batts?

 

[rwreuter]

For a garage with no living space above would you need a vapor barrier or just unfaced batts?

no living space = no vapor barrier. you want the moisture to go through the sheetrock and the insulation and exit through the attic venting.

 

[NXGTS]

For a garage with no living space above would you need a vapor barrier or just unfaced batts?

I'm wondering about this too. My house ceiling is blown in with no vapor barrier. I was going to do the detached garage in kraft face batts.

 

[trainer]

personally I like blown-in. It's faster and easier to install. To get the right depth, rip some 3/4 by 1/4" sticks the depth you want and staple them to your rafters for a guide. "loft" the insulation into place so it doesnt get too compacted.

 

[theoldwizard1]

Blown in, especially cellulose, will settle over time.

 

[JSBriggs]

I HATE blown in. If you ever need to do any work later on it is very messy. As for cost or efficiency, Im not sure, but after dealing with the existing blown in on my house remodel, Ill stick to batts.

-Jeff

 

[Falcon67]

Blown fiberglass is cheaper than batts. My ceiling insulation budget based on retail pricing shows (for 960 sq/ft) $300 blown in @ R-19 (OC pink AttiCat) vs 8 bags at $408 for R19 EcoTouch faced batts. The ceiling batts come up short by maybe 1/4 bag. I was sold on the blown in, but since I'll probably be piece-mealing the insulation and drywall, it'll probably be batt bags every payday for the shop.

 

[Highbeam]

Wow, I am the opposite. I think it would be foolish to use batts in a ceiling. Labor is much much higher, product is much poorer since you can't possibly cut and place it perfectly around every obstruction, and it is not going to be a coninuous blanket of insulation like blown in. There are air sealing benefits to some blown in products as well. Sheesh, nobody should be using batts anymore.

The vapor barrier in many US homes is painted onto the sheetrock. They have come up with a paint that is supposed to be an effective vapor barrier so you won't see plastic sheets in most places.

Of course you need a vapor barrier on one side of the insulation. No living space above means the cold side is above which means the vapor barrier should be on the garage side of the insulation. Otherwise, the vapor will condense somewhere within the insulation as temperatures drop.

Another important feature of a good vapor barrier is air sealing. You loose heat by conduction and convection. Hot air escaping through your ceiling adds dramatically to your heat load. A good vapor barrier will minimize air loss.

Batts schmatts. You can often hire an insulation company to blow in insulation for less money than it would cost you to buy the insulation.

 

[Eds_tls]

We just had our attic blown in. 1300 sq feet of attic space. I don't remember the R value off hand, but it was one step up from the contractors initial recommendation

I priced out batts from the big box. Just over $1000 in material alone

I had the same R value blown in for $770 out the door from a local contractor. He was in and out in 3 hours and it looks top notch. Supposedly its stabalized and won't settle. I was very happy with the work he did

 

[BADSIX]

you should get a bid from an insulator, i saved about 300.00 and i came home from work and it was all done and done right

 

[MrMark]

Wow, I am the opposite. I think it would be foolish to use batts in a ceiling. Labor is much much higher, product is much poorer since you can't possibly cut and place it perfectly around every obstruction, and it is not going to be a coninuous blanket of insulation like blown in. There are air sealing benefits to some blown in products as well. Sheesh, nobody should be using batts anymore.

The vapor barrier in many US homes is painted onto the sheetrock. They have come up with a paint that is supposed to be an effective vapor barrier so you won't see plastic sheets in most places.

Of course you need a vapor barrier on one side of the insulation. No living space above means the cold side is above which means the vapor barrier should be on the garage side of the insulation. Otherwise, the vapor will condense somewhere within the insulation as temperatures drop.

Another important feature of a good vapor barrier is air sealing. You loose heat by conduction and convection. Hot air escaping through your ceiling adds dramatically to your heat load. A good vapor barrier will minimize air loss.

Batts schmatts. You can often hire an insulation company to blow in insulation for less money than it would cost you to buy the insulation.

Makes sense on the vapor barrier for a primarily cold climate where heating is heavy. What about for a hot climate like Florida or a temperate zone like beach cities in So Cal? I don't know that a vapor barrier as you posted makes sense there. On heavy AC house that doesn't use much heat in the winter you may not want the barrier, at least not on the inside of the wall. Curious as to your thoughts. I do know that most places shouldn't have a vapor barrier based on what I've read.

Let's refine the question: A house in a hot portion of Southern Cal. No, it's not mine, where I live in SoCal it's cold. This house uses heavy AC during the summer and a little heat during the winter, not that much though. Do you put the kraft faced batts in the ceiling over an attic? Or, do you just go with unfaced batts? My initial reaction is to say unfaced unless someone knows better. On this house the ceiling was faced but curiously the walls were unfaced. I wouldn't put much stock in that though.

 

[Highbeam]

The vapor barrier goes on the hot side. There's always supposed to be a vapor barrier. I don't have special experience in southern cooling climates but perhaps someone down south knows the answer with enough confidence to advise.

Imagine a hot hot coastal town with moist outside air and high temp differential inside to out like Georgia. That moisture will condense somewhere within the insulation without a vapor barrier.

 

[Will67]

I had my attic insulated with blow in cellulose....went from R-11 to R-40 and it cost $1,200 to cover apx 1,300 sqft.

I agree it is a ***** to do any modifications that involves opening the ceiling, but that is why I have a shop vac to clean up after for.

 

[MrMark]

The vapor barrier goes on the hot side. There's always supposed to be a vapor barrier. I don't have special experience in southern cooling climates but perhaps someone down south knows the answer with enough confidence to advise.

Imagine a hot hot coastal town with moist outside air and high temp differential inside to out like Georgia. That moisture will condense somewhere within the insulation without a vapor barrier.

That's the problem with a vapor barrier. Where is the hot side? In Alaska the hot side is the inside, whereas in Florida the hot side is the outside. If you put the vapor barrier on the inside as you propose with an AC house then the warm moist outside air will condense on the inside of your wall - I would think.

Too many I have seen jump on the vapor barrier bandwagon without considering the science.

 

[Highbeam]

Good thing most of us don't live in an area that experiences both extremes and that we don't move our homes from AK to FL. Most of us live in one place where it is cold and code requires a vapor barrier on the heated side, this is no bandwagon.

 

[kyles974]

Last fall I use this:

http://www.homedepot.com/Building-M...splay?langId=-1&storeId=10051&catalogId=10053


it claims it does not settle. I can't say. Have not been up there since I blown it in.

As far as claiming 4hr from start to finish, my experience was this:

My son and me started, after the second bag threw the machine, I thought there is no way this can be done in four hours.(reviews I thought were BS) After the 5 or 6th bag, I learned to slow down and let the machine work, instead of trying to make the machine work faster.

We did 22 bags around the 4hrs.

I did blow in 15yrs ago and would not do it again untill I looked into this. Glad I did! The inventor of this machine is a smart person. Simple unit that works perfect! I have not seen something that works this good in a long time.

 

[MrMark]

Good thing most of us don't live in an area that experiences both extremes and that we don't move our homes from AK to FL. Most of us live in one place where it is cold and code requires a vapor barrier on the heated side, this is no bandwagon.

I don't know about any of that. But, the vapor barrier seems to be limited in usefulness to very cold climates. The research I have done agrees with this.

 

[pro machine Engineering]

you should get a bid from an insulator, i saved about 300.00 and i came home from work and it was all done and done right

this is the way to go I did the same thing. when I was checking around you can have it professionally done for about the same price as doing it yourself The housing market like it is has the guy that do this cutting each others throat to get work. and they buy in volumes so they get a pretty good discount on the insulation

 

[MrMark]

This is pretty authoritative on the vapor barrier and whether it should be used.

http://www.buildingscience.com/documents/digests/bsd-106-understanding-vapor-barriers

 

[MrMark]

OC and LA (Zone 3B Hot dry) get no vapor barrier. Makes sense. Now I know to buy the unfaced batts. Done.

 

[phbsales]

Vapor barrier is installed on the "Warm in Winter" side of the wall.....

 

[MrMark]

Vapor barrier is installed on the "Warm in Winter" side of the wall.....

Yeah, unless you happen to live in Zones 1, 2, 3, or 4. Which includes most of the population of the US. Good info there.

 

[Highbeam]

I live in zone 4 and a class 1 barrier, poly, is required. Some parts of four and in the hotter zones it doesn't appear to be required.

Another issue is that this is for residential construction. Not sure about garages.

 

[green.bubbly]

FYI, lowes has JM R19 on sale for under 32 cents/sq. foot. For your attic, that would be $240.00


HD had R30 unfaced for $9.97. Again, less than 32 cents per foot.

 

[Dragster Racer]

I went with blown in for many of the supporting reasons listed. I have to say though, that no one was cheaper than doing it myself. I always hear about that, but in the boonies, it would have cost me $400 more to do my 40x40 ceiling if I had someone do it. I figured that was over $100/hour on my time. I'm not worth that on a good day.

 

[ratdoggy]

Wow, I am the opposite. I think it would be foolish to use batts in a ceiling. Labor is much much higher, product is much poorer since you can't possibly cut and place it perfectly around every obstruction, and it is not going to be a coninuous blanket of insulation like blown in. There are air sealing benefits to some blown in products as well. Sheesh, nobody should be using batts anymore.

The vapor barrier in many US homes is painted onto the sheetrock. They have come up with a paint that is supposed to be an effective vapor barrier so you won't see plastic sheets in most places.

Of course you need a vapor barrier on one side of the insulation. No living space above means the cold side is above which means the vapor barrier should be on the garage side of the insulation. Otherwise, the vapor will condense somewhere within the insulation as temperatures drop.

Another important feature of a good vapor barrier is air sealing. You loose heat by conduction and convection. Hot air escaping through your ceiling adds dramatically to your heat load. A good vapor barrier will minimize air loss.

Batts schmatts. You can often hire an insulation company to blow in insulation for less money than it would cost you to buy the insulation.

I'm confused now about the vapor barrier. If you blow in insulation where is the vapor barrier? If I used batts I can either get faced or unfaced. Which do I get? Which way does the vapor barrier go if I need to get faced? My garage ceiling has no insulation now and has no living space above it?

 

[MrMark]

Ohio likely needs faced, with faced side down in the ceiling. You are primarily a heating days area. You heat more than you cool thus you use the faced.

 

[MrMark]

I live in zone 4 and a class 1 barrier, poly, is required. Some parts of four and in the hotter zones it doesn't appear to be required.

Another issue is that this is for residential construction. Not sure about garages.

I don't see where you get that. Zone 4 for the marine areas requires either class II or III depending on your exterior clading. Do you have a vapor barrier on the outside too? Tyvek is not a vapor barrier, it is quite the opposite, it is vapor permissive and that is one of its greatest selling points.

Class III is latex paint. Class two is kraft paper on the batt. Where I live is essentially marine within SoCal and I could use Kraft paper or forget about is really. I would never even think of using poly on the inside.

 

[stingry]

which is cheaper for attic insulation over the garage: 750 sq ft ceiling

purchase 24" 2x6 unfaced batts


or


buy insulation and use lowes or home depots free blower

To answer the original question, I checked at my local Home Depot.

R38 unfaced batts $1.00 per sq ft
R38 fiberglass blow-in $.58 per sq ft

So, blown-in approx. 60% of unfaced batts


Cheers
Steve

 

[MichMan517]

The reason I used batts in my garage ceiling is there is a stoarage area down the middle third, and realy didn't want to deal with the dust from the blown-in all over everything. Cellulose is obviously the better choice in most cases, and had my whole house blown with cell 12 years ago when we built it, and have seen noticable settling with the product back then. Looks like I will have to add some more here pretty soon. If there is no storage up in the ceiling, blow it in.

 

[matt60j]

When I did the blown i put my laser transit in the attic at the desired depth and spray painted lines on all the rafters and supports. -MATT

 

[Highbeam]

When I did the blown i put my laser transit in the attic at the desired depth and spray painted lines on all the rafters and supports. -MATT

I grabbed a handful of the free insulation depth gauges and stapled them to the trusses. These gauges are like rulers but list not only inches but R values for the fiberglass.

I'm not a fan of cotton candy (cellulose) for insulation. Note the "ose" at the end of cellulose. Ose means sugar like sucrose, fructose, lactose, etc. Sugar burns, bugs eat sugar, mold eats sugar and I don't want to depend on some sort of application of some sort of chemical to prevent that. Lots of folks like cellulose though.

 

[Dragster Racer]

I grabbed a handful of the free insulation depth gauges and stapled them to the trusses. These gauges are like rulers but list not only inches but R values for the fiberglass.

I'm not a fan of cotton candy (cellulose) for insulation. Note the "ose" at the end of cellulose. Ose means sugar like sucrose, fructose, lactose, etc. Sugar burns, bugs eat sugar, mold eats sugar and I don't want to depend on some sort of application of some sort of chemical to prevent that. Lots of folks like cellulose though.

You do know that wood is almost 50% cellulose right?

Anyhow...If you are blowing in, I would put the vb in before putting the ceiling up. Then blow on top of the vb. Or use unfaced batts if you choose.

 

[Rich H.]

Cellulose is made primarily from recycled newspapers. There is no sugar in it.

 

[Dragster Racer]

Cellulose is made primarily from recycled newspapers. There is no sugar in it.

Right. The blow in stuff used for insulation. But cellulose is also what makes up a lot of wood. You are absolutely correct, but I kind of thought the poster was kidding.

 

[Highbeam]

cellulose is a sugar.

 

[rwreuter]

Thanks for all the information.......