Insulate Ceiling Before or After Sheetrock?

[thoyer]

Finishing off the inside of my new garage. Couple questions from those who have been down this road before.......

Should I use faced insulation and install before the sheetrock or use unfaced insulation and put it in after rocking?

I'll be using 10ft panels and plan on staggering each row across the trusses. I do not look forward to taping all of the **** joints and was thinking - What if I align the ends of the boards across the width then use maybe a 1" wide molding of sorts to cover the **** joint across the width? Ceiling is approx 26 wide by 36 long. 950 sq ft so I'd end up with three of the "strips" covering the **** joints.

Thoughts?

Tom

 

[QwikKotaTx]

I assume you are talking about the ceiling and have access from the attic. It may be cheaper and easier to blow in insulation after you do the sheetrock. Putting in the insulation from below before sheetrock you will have to use the wire pieces to hold the batts in. They might add an additional $50 to $100 in cost.

 

[bdbecker]

One advantage of sheeting first is it opens up the option for blown-in insulation, which is a pretty good savings over batt insulation. Otherwise the pros and cons of either batt option aren't really enough to outweigh one another and it really comes down to just picking which method you prefer.

Having just insulated my ceiling with batts (maybe a month ago) after I sheeted the ceiling, I can tell you that its not a difficult job. I used a mop handle to push the batts into the ends of the ceiling where it was difficult to reach. It took me less than two hours to do my 24x24 garage working alone.

 

[thoyer]

I assume you are talking about the ceiling and have access from the attic. It may be cheaper and easier to blow in insulation after you do the sheetrock but I would avoid the cellulose style as that can be food for bugs and is flammable. Putting in the insulation from below before sheetrock you will have to use the wire pieces to hold the batts in. They might add an additional $50 to $100 in cost.

Yes, ceiling. Don't want to go the blown in route. Think I'll rock then insulate from above.

Thanks

 

[thoyer]

One advantage of sheeting first is it opens up the option for blown-in insulation, which is a pretty good savings over batt insulation. Otherwise the pros and cons of either batt option aren't really enough to outweigh one another and it really comes down to just picking which method you prefer.

Having just insulated my ceiling with batts (maybe a month ago) after I sheeted the ceiling, I can tell you that its not a difficult job. I used a mop handle to push the batts into the ends of the ceiling where it was difficult to reach. It took me less than two hours to do my 24x24 garage working alone.

Thanks for the reply. Think I'll rock then batt like you did.

Tom

PS: I can copy code at 25wpm but can't read it for ****!

 

[NUTTSGT]

I'd prefer to insulate first, staple the batts (kraft faced) to the trusses and then sheetrock it, if that's your choice to cover the ceiling.

Some people are not apt at crawling across truss chords and can/have fallen through. Worst case, a slip and crack newly hung sheetrock which will need replaced or fixed.

 

[spudley]

I'll be using 10ft panels and plan on staggering each row across the trusses. I do not look forward to taping all of the **** joints and was thinking - What if I align the ends of the boards across the width then use maybe a 1" wide molding of sorts to cover the **** joint across the width? Ceiling is approx 26 wide by 36 long. 950 sq ft so I'd end up with three of the "strips" covering the **** joints.

Thoughts?

Tom

I'd insulate first with staple on batts, and I'd finish staggered **** joints on the sheetrock. It'll take longer but it'll look better. Just take your time and feather it out.

 

[matt_i]

My 0.02 is if using batts is to place from below, so much more open, can work from a ladder or scaffold-platform.

Otherwise you have to haul the batts up thru the opening and as others have pointed out, you walk the tightrope of the stepping stones (studs).

I personally don't like the idea of using the wood strips, I don't think they will seal tightly even if backed up by the bottom chords and you'll have an amount of accumulated air leakage that will be significant. Fiberglass cannot stop that air movement. Loose fill would come closer to blocking airflow. You could caulk the joints with something springy like Big Stretch but there's a lot of linear footage to cover.

 

[pbon]

You can buy rolls of mesh that you staple to the joists to hold blown in insulation. They you sheet rock over. You do not need to sheet rock first. The mesh will also hold roll style of insulation.

 

[Mikemac1]

I have a hip roof garage. I installed the batts (Rock wool) from below. What a pain in the ****. I ended up having to make strapping to hold the batts up, 2 for each cavity. The batts were not perfectly sized. I would never do that again. Poly, sheet, and blow in from attic. The machine is free is you buy the insulation. I added 12” to my house attic with a blower. One helper feeding the machine. It was done in an hour.


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[Kaizen]

Far easier to insulate while standing. Even if it’s on a ladder.


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[jetnow1]

Personal preference would be to put a vapor barrier if needed up first, then sheetrock then
do blown in, I refuse to use batts unless there is no other choice. The difference between
blown in insulation and batts is the amount of infiltration due to then poor fit of most batt installs. In situations where there is air movement their can be a 40% difference in the effective r value.

 

[K'ledgeBldr]

Personal preference would be to put a vapor barrier if needed up first, then sheetrock then
do blown in, I refuse to use batts unless there is no other choice. The difference between
blown in insulation and batts is the amount of infiltration due to then poor fit of most batt installs. In situations where there is air movement their can be a 40% difference in the effective r value.

This^^^ 100%!

 

[joe--h]

I assume you are talking about the ceiling and have access from the attic. It may be cheaper and easier to blow in insulation after you do the sheetrock but I would avoid the cellulose style as that can be food for bugs and is flammable. Putting in the insulation from below before sheetrock you will have to use the wire pieces to hold the batts in. They might add an additional $50 to $100 in cost.

Cellulose insulation is treated with borates to repel bugs and it does not burn.

Joe H

 

[R6 Racer]

I'm curious, why you "Don't want to go the blown in route"?

When I did my ceiling last summer everything about blown in seemed better when I looked at it. Better/tighter coverage, way less $$$$$ & super simple to do. I just stood on a ladder with my body sticking up threw the attic access door & aimed the discharge hose where I wanted the insulation.
IMHO insulating doesn't get any easier than blown in.

My suggestion is 6mil poly vapor barrier & blow in what is needed for your area.


Steve

 

[QwikKotaTx]

Cellulose insulation is treated with borates to repel bugs and it does not burn.

Joe H

Thank you, I didn't know that. I will edit my post.

 

[Toomanytools?]

Sounds like the OP made up his mind. Just my two cents I'm looking at both wall and ceiling insulation now and blow in is about half what batts are. That's looking at Big Orange prices, you might also be surprised at what a insulation company charges compared to you doing batts and them doing blow in, many times same or cheaper.

 

[larry4406]

Whatever you do, don’t forget to put your soffit vent baffles in beforehand.

 

[JohnKal]

Whatever you do, don’t forget to put your soffit vent baffles in beforehand.

Great point!

 

[Kevin54]

Insulate then rock. If you don't, you're screwed

 

[thoyer]

Sounds like the OP made up his mind. Just my two cents I'm looking at both wall and ceiling insulation now and blow in is about half what batts are. That's looking at Big Orange prices, you might also be surprised at what a insulation company charges compared to you doing batts and them doing blow in, many times same or cheaper.

Well I had made up my mind until I started reading all of the replies about blown in insulation tonight. Must admit, I'm giving it some thought.

I can stand up in the center of the attic area and plan on putting down some plywood in the center for storage. so doing batts or blown in won't be very difficult.

I'll be price comparing the two methods to see how it compares, material and machine rental vs roll insulation.

Yes, I'll remember the soffit vents - on the shopping list already.

 

[Jazz1]

insulate then vapour barrier then drywall

 

[cdestuck]

The 2 big box stores will give you free machine rental with the purchase of so many bundles of insulation. At least the last time I checked they did.

 

[ItsNemo]

Another vote for blown in....it's super simple and does a far better job. You can do blown in for an entire attic in a couple hours where it would take a couple days to do a good job with batts.

 

[iamrfixit]

If you have a soffit that is or can be vented I'd suggest to staple up ventilation chutes in every rafter bay. Once those are in place, tuck fiberglass around the chutes and between them and the top plate. This is done to keep blown insulation from getting out into the soffits. This is inexpensive and very easy to do before the ceiling goes in.

Then you can put up your vapor barrier and drywall. The work you did on the chutes will make it a piece of cake to actually blow the insulation. You can just blow away and not have to worry about insulation filling up or blocking the soffit vents, of course you don't want to blow it directly into the top of the chutes. I can usually just work from the center, push the hose out toward the wall and fill the space up.

Cellulose is much more economical for thicker layers and higher R value. It gives a very even coverage, fills all the nooks and crannies, and doesn't leave room for gaps/leakage around every piece like batt insulation will. With batts a few gaps here and there can be almost like no insulation at all. Most regions suggest at least an R-30 in the attic and more is better. Good attic insulation is the most important part of all your insulation.

 

[Dagny]

I think the price is the same when you figure in the settling of blown in.

 

[iamrfixit]

I think the price is the same when you figure in the settling of blown in.

Not true.

At R-40 cellulose is easily less than half the cost of fiberglass batt or roll, and the settling is accounted for and built into the coverage listed on the package.

 

[Jazz1]

Only drawback to blown in is many of us store **** in attic. I bought oil pan last year not realizing I had one in garage attic.

 

[iamrfixit]

Unless you have a dedicated space framed up with a floor to create a storage space in the attic, it makes no difference what type insulation you're using. Smashed down fiberglass doesn't work any better than smashed down cellulose.

Unless you're garage is 30+ feet wide or you have a 6:12 or greater pitch on the roof, there isn't much room for storage anyway, especially when you add 12" of any type insulation.

Sticking with minimal attic insulation so you can store junk up there does not make sense. Why would you waste all that money on lost heat to store stuff you probably never use. When it's been up there so long you don't remember you had it, there's obviously no reason to store it. Getting stuff in/out through a small attic hatch is difficult, which also makes actually doing it unlikely.

 

[nadogail]

Add walk boards and lights is n your attic. I prefer 16 or 18 inch wide boards spaced above the truss chords.
The switch for the lights just inside the access panel.

 

[derek_m]

The amount of people preferring blown in is surprising. From my experience of having to get into an attic with blown insulation to do electrical, cut into ceilings, etc. it has been probably my least favorite task. It absolutely *****, wish the previous owners never did it. I have this yellow chopped up fiberglass insulation between the joists, then gray stuff over top. The gray stuff is in the walls too. Anywhere I encounter it I pull it out and replace with regular batt insulation.

 

[i4ni]

In my 26 x 40 dog kennel I did vapor barrier then sheet rock then loose fiberglass. Couldn't be happier.I have a wall that runs the entire 40 foot right down the center so I put 4x8 sheets of osb in the center from one end to the other and then put 2x8 sheets of osb nailed to the truss webs for shelfs about a foot higher on either side. Gained a ton of attic storage. Then I built a cart by putting casters on a solid core door layed flat so I can set on it and pull my self and whatever I want to put up there. That works great. Beats the hell out of being on your hands and knee's. Oh, one other thing I stapled different colored ribbon above all junction boxes before I insulated so I could easily find the right box if I ever need to. I should take pictures someday.

 

[u2slow]

I like this thread

Is there a preferred setup when your exposed-screw roof is prone to leaking? How would one easily find leaks after insulation, vapour barrier, and boarding?

My ceiling is 19' up. 20' span 2x4 bottom chords 24" on center. I had the idea of doing batts to fill between the ceiling joists, and roll or blow-in on top again. Don't really want to be adding unnecessary weight up there for walking on. Also don't want to mis-step. Not interested in being up there at all really...

 

[James-W]

If it were mine, I would get a quote for hiring the insulation done. You will probably be shocked at how inexpensive it is to hire it done. Also, before I put drywall on the ceiling I would get a quote for hiring it put up and finished. The guys who do this everyday will have the job done so quick it will amaze you and the cost would likely be less than what you think it would be. The job will be done quickly and it will look great.

 

[Junkman]

I have to agree with James-W. When I built our home back in 1983, the insulation quote for fiberglass bats was less than I could purchase it for. The same when it came to the sheetrock. I got a quote for sheet rocking the entire house that was less than I could buy the materials for. In fact, it was so inexpensive, that I had them do a skim coat of plaster over the special plastering board. I never regretted having done it that way. If I were doing it again today, I would also consider using closed cell foam, since it seals the leaks from the living space into the attic.

 

[MushCreek]

When I did our house, I hired a guy to do blown-in stabilized cellulose. His price, including labor was about the same as buying the materials at HD. No thanks; I'll let someone else do it. I went R-49; pretty hard to do with batts.

 

[ddawg16]

If it were mine, I would get a quote for hiring the insulation done. You will probably be shocked at how inexpensive it is to hire it done. Also, before I put drywall on the ceiling I would get a quote for hiring it put up and finished. The guys who do this everyday will have the job done so quick it will amaze you and the cost would likely be less than what you think it would be. The job will be done quickly and it will look great.

I have to agree with James-W. When I built our home back in 1983, the insulation quote for fiberglass bats was less than I could purchase it for. The same when it came to the sheetrock. I got a quote for sheet rocking the entire house that was less than I could buy the materials for. In fact, it was so inexpensive, that I had them do a skim coat of plaster over the special plastering board. I never regretted having done it that way. If I were doing it again today, I would also consider using closed cell foam, since it seals the leaks from the living space into the attic.

I farmed out the insulation job on my 2-story addition....I figure I maybe would have saved $500 if I did it myself.,,,,maybe. When you consider how many trips I would have had to make to HD....all the itching....that $1400 check was worth it.

I go to work....not insulated....I come home....insulated....and they cleaned up behind themselves.

On the type of insulation....since it's only a garage...I'd be inclined to go batt.....makes it easier to make mods to the ceiling....like can lights or outlets....just pull the batt aside...do work, put it back.

 

[bdbecker]

...On the type of insulation....since it's only a garage...I'd be inclined to go batt.....makes it easier to make mods to the ceiling....like can lights or outlets....just pull the batt aside...do work, put it back.

I was planning on blown-in insulation but changed my mind at the last minute because of this exact reason. 240v electrical and NG service are in the long term plans for my garage and I knew I'd be kicking myself later if I didn't do batts.

 

[QwikKotaTx]

I would have loved to hire out my insulation and wall boards but I have so much junk in the way the crew would have never started the job. As for the ceiling insulation I decked the attic for storage and want to use white faced insulation underneath and not add more boards (weight) to the joists so I can't do blown in.

 

[Bolson32]

+1 for Blown-in insulation. Stupid easy to do. Be sure to put your baffles in and get all of your wiring done BEFORE you put up the ceiling though. Crawling around under a sloped roof trying to put baffles in is miserable.

OP, you also might want to check with your utility provider. Xcel energy here does a decent rebate that you can do every year if you have the insulation professionally installed and sealed, you get like $450 back. Add the cost of the install and the hassle of doing it, it ends up only saving a few hundred bucks usually to DIY. Generally worth it, if it's available, unless you're on a mega budget build.