# Help on garage project...



## DesertRatTom (Jul 3, 2012)

Getting ready to install insulated ceiling in my garage. The firewall between house and garage goes floor to ceiling with no exposed 2x4 on which to attach the insulation, or drywall. So I have to put up a 2x4 up and attach it. 
Question is, can I mount it (with long screws) on top of the existing drywall, or should I cut the drywall out and mount the 2x4 directly to the underlying wood? 

I know the drywall is extra thick and fire retardant. (a 2 hour wall as I understand it), so I don't know if I can legally break through the drywall, or if there is some appropriate way to handle this?


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## Dan3103 (Feb 12, 2014)

Have you considered removing the existing drywall and insulating, then putting new drywall in? Usually, 2 hour firewalls are 5/8" drywall on both sides of the wall, but sometimes contractors will use two layers of 1/2" on the garage side to gain the necessary thickness. I would think that it would be much easier to install insulation in the existing stud cavity instead of tacking on an additional 2x4 frame to hold the insulation/drywall...

If you do make cuts into the existing drywall, the holes need to be well sealed with mud to prevent hot gasses from entering the attic space. Those holes can cause a small fire in the garage to move into the attic and burn off the roof. I saw that more than a few times over the years...


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## DaninVan (Jan 1, 2012)

Do NOT cut into the drywall, Tom!!! I mentioned a couple of years back, about an arsonist in my neighbourhood, back then,.
He'd started a fire in the rear of a four-plex and the fire was so hot that it consumed everything in it's path...but it was stopped dead in its tracks by the 5/8" 'Fireguard' drywall. Man, was I impressed!
Dan (above) is absolutely correct, but getting rid of old drywall has become a bit of a p.i.t.a., and if you can live with losing 4" of floor space go with the new framed wall...just my personal choice. 
*Not necessary to anchor it to the existing wall.* Nail it through to the ceiling framing and the floor, same as you would with any other partition wall. Run your wiring then insulate and board. If you can get some help, use 12' sheets or whatever works for your wall length, horizontally! I know stick thinks vertical is the way to go, but taping and filling a 4' high seam at waist height and maybe one or two vertical joints beats a bunch of 8' high joints all to Hell!


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## Knothead47 (Feb 10, 2010)

Glue foam insulation sheets to the wall?


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## paduke (Mar 28, 2010)

We maintain firewalls in construction. Maintain existing You can screw 2's to the corresponding studs if you want 1 1/2" cavity. Why insulate an interior wall? soundproofing?


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## Herb Stoops (Aug 28, 2012)

paduke said:


> We maintain firewalls in construction. Maintain existing You can screw 2's to the corresponding studs if you want 1 1/2" cavity. Why insulate an interior wall? soundproofing?


I agree, why are you insulating the wall, Tom?
I like the suggestion of 1 1/2" furring and foam bat insulation from Lowes, if it is necessary to insulate.
Are you talking about the wall separation in the attic?
Herb


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## RainMan 2.0 (May 6, 2014)

Wish I had insulation


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## Semipro (Mar 22, 2013)

Hold on? if it's a firewall between the house and the garage the walls already insulated


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## Cherryville Chuck (Sep 28, 2010)

Semipro said:


> Hold on? if it's a firewall between the house and the garage the walls already insulated


Exactly.


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## DaninVan (Jan 1, 2012)

"Hold on? if it's a firewall between the house and the garage the walls already insulated"

...you can never have too much insulation, right, Rick?


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## RainMan 2.0 (May 6, 2014)

DaninVan said:


> "Hold on? if it's a firewall between the house and the garage the walls already insulated"
> 
> ...you can never have too much insulation, right, Rick?


Agreed . I only have one piece of insulation that Honest John sent me , and it's still pretty darn cold in there :fie:


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## DaninVan (Jan 1, 2012)

Only if you actually go _in_ there, Rick. It's kinda like the Schrodinger's Cat thing! lol!


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## DesertRatTom (Jul 3, 2012)

paduke said:


> We maintain firewalls in construction. Maintain existing You can screw 2's to the corresponding studs if you want 1 1/2" cavity. Why insulate an interior wall? soundproofing?


I think I am talking about putting up a ledger board.

I am insulating the ceiling, not the wall, then putting up drywall on the ceiling to enclose the insulation up there. The garage walls are already insulated and drywalled.

Just need to know whether to cut through the drywall parallel to the other beams, and attach a new 2x4 ledger board to the existing framing underneath the existing drywall, or to mount that 2x4 kedger through the drywall into to wood on the other side with some really long screws. I will staple the insulation to this new 2x4 ledger and attach the last 2 feet of the drywall to it. It won'd be bearing much weight. This is all on the house side of the garage. I'm putting in the insulation, but hiring someone to put up the ceiling.

I am not going to put in a frame, just a ledger board.

Putting up R38 insulation up there. Tired of freezing in winter, baking in summer.


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## woodknots (Mar 7, 2012)

Tom as I understand it, you can insulate/drywall the ceiling, but when you get close to the interior wall, you have nothing that you can attach the insulation/drywall to - is that correct?

How do your joists run - are they parallel to the interior wall or perpendicular?


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## DesertRatTom (Jul 3, 2012)

vchiarelli said:


> Tom as I understand it, you can insulate/drywall the ceiling, but when you get close to the interior wall, you have nothing that you can attach the insulation/drywall to - is that correct?
> 
> How do your joists run - are they parallel to the interior wall or perpendicular?


Exactly on the first point. And the joists run parallel to the interior wall. I think I confused everyone because I didn' t have the labels right.

I have done this on an exterior wall, but not on a fire wall with drywall already on it.


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## woodknots (Mar 7, 2012)

OK, what is the distance between the interior wall and the closest joist? How long are the joists or what is the distance front to back? What is above the joists - is it an attic or open space and do you plan to put anything up there?
If the distance between the wall and first joist isn't that great I would consider building a bulkhead, attached to the first joist, butted against the wall without fasteners. If the distance is excessive, you couldn't do that because it would likely sag at the wall. The alternative is to extend a some two bys, across the top of the first two joists towards the wall and attach the bulkhead to the joist and to those extensions. Does that make sense?


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## DesertRatTom (Jul 3, 2012)

vchiarelli said:


> OK, what is the distance between the interior wall and the closest joist? How long are the joists or what is the distance front to back? What is above the joists - is it an attic or open space and do you plan to put anything up there?
> If the distance between the wall and first joist isn't that great I would consider building a bulkhead, attached to the first joist, butted against the wall without fasteners. If the distance is excessive, you couldn't do that because it would likely sag at the wall. The alternative is to extend a some two bys, across the top of the first two joists towards the wall and attach the bulkhead to the joist and to those extensions. Does that make sense?


I think you are talking about something like outriggers. Span several 2x4s across the existing joists. The distance between joists is 24 inches on center. 

The distance between the wall and the first joist is almost the same. So that's why I think a ledger board is the best solution. BUT MY QUESTION REMAINS THE SAME: Can I mount the ledger board on top of the drywall, or do I need to cut the drywall away and mount the ledger board directly on the underlying wood? 

The minor problem I see with outriggers is that it may interfere with installing the insulation. But I guess I could suffer through that for two 25 foot lenghts. I'll just itch a little more.

I would want the outriggers to span at least two joists, but I think I would still want a ledger board suspended from the outriggers to attach to the wall as well.

So even with outriggers, I still have the same problem, cut through the drywall or drill through it?

Thanks for the suggestion Vince. Best bet so far.


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## Semipro (Mar 22, 2013)

Tom
Just go ahead and screw or nail a Ledger board to the drywall,just find the studs in the wall you will have use longer nails or screws, you might want to also use liquid nail.
If it around 24" from the last truss to the wall you'll be fine


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## DesertRatTom (Jul 3, 2012)

Semipro said:


> Tom
> Just go ahead and screw or nail a Ledger board to the drywall,just find the studs in the wall you will have use longer nails or screws, you might want to also use liquid nail.
> If it around 24" from the last truss to the wall you'll be fine


Cool, that's what I hoped would work. I think if I use some 4 or 5 inch screws, hit the studs or the joist on the other side of the drywall, then the weight (insulation and 1/4 sheet of drywall) will be OK. I think it would be smart to do the outriggers as well. At least, that's the plan for now.


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## Cherryville Chuck (Sep 28, 2010)

What John said. Still trying to figure out what you are calling outriggers.

I try to avoid using screws in framing if I can. I see Mike Holmes do it all the time but I still think it's a bad idea in most cases. The reason why is all the screw failure I saw when I lived in northern Alberta on my front steps. They were a set of steel risers with boards screwed down from underneath and I kept getting broken screws. It finally dawned on me why. Screws are tempered to be hard enough so that you can drive them and without stripping the heads out prematurely. This tempering also makes them brittle so that they don't tolerate much flexing before they snap off.

Nails on the other hand are quite soft and will flex back and forth quite a few times before there is enough metal fatigue to cause them to fail. Nails are old school but I still think they are the best choice in framing because most framing moves as time and seasons change.


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## Semipro (Mar 22, 2013)

Tom
If it was me I would use 1/2" drywall yes it heavy but 1/4" would probably give you a wavy cealing. I did not know you could still buy 1/4"


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## woodknots (Mar 7, 2012)

Cherryville Chuck said:


> What John said. Still trying to figure out what you are calling outriggers.


Charles - the "outriggers" that Tom is referring to would be 2x4s cantilevered on top of the joists towards the wall.
I suggested this type of construction because it was assumed that Tom didn't want to penetrate the firewall, or at least that's the direction the discussion took.

I agree the simplest solution is to attach a ledger board directly on top of the drywall to support the ceiling drywall and insulation.

It seems that framing the old fashioned way, with one foot holding down the joint while hammering a couple of nails is a lost art - but then these guys on TV wouldn't be able to brandish that bright yellow driver for the camera to benefit the sponsor of the show.


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## Everend (Mar 15, 2013)

Semipro said:


> Tom
> If it was me I would use 1/2" drywall yes it heavy but 1/4" would probably give you a wavy cealing. I did not know you could still buy 1/4"


No way 1/4" drywall will span 24" and not sag. Very likely 1/2" will sag too. I'd use 5/8" on a ceiling every time.


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## Everend (Mar 15, 2013)

Semipro said:


> Tom
> Just go ahead and screw or nail a Ledger board to the drywall,just find the studs in the wall you will have use longer nails or screws, you might want to also use liquid nail.
> If it around 24" from the last truss to the wall you'll be fine


I agree. If you are unsure about doing this and want more support, install bridging from the last truss to your ledger. There is probably bridging across between the other trusses. If not, consider adding these to reduce movement that will loosen the drywall nails/screws over time.


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## Bushwhacker (Jun 16, 2009)

Semipro said:


> Tom
> Just go ahead and screw or nail a Ledger board to the drywall,just find the studs in the wall you will have use longer nails or screws, you might want to also use liquid nail.
> If it around 24" from the last truss to the wall you'll be fine


I agree with Semipro. This seems to be getting out of hand. A simple 2x4 nailed to the existing wall will do it. You will need the 2x4 to attach the ceiling sheet rock to anyway.
Sort of like dead wood.
David


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## Bushwhacker (Jun 16, 2009)

DesertRatTom said:


> Getting ready to install insulated ceiling in my garage. The firewall between house and garage goes floor to ceiling with no exposed 2x4 on which to attach the insulation, or drywall. So I have to put up a 2x4 up and attach it.
> Question is, can I mount it (with long screws) on top of the existing drywall, or should I cut the drywall out and mount the 2x4 directly to the underlying wood?
> 
> I know the drywall is extra thick and fire retardant. (a 2 hour wall as I understand it), so I don't know if I can legally break through the drywall, or if there is some appropriate way to handle this?


Yes and no. Yes you can attach the 2x4 directly to the wall and no, you don't have to cut into the wall.


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## DesertRatTom (Jul 3, 2012)

Cherryville Chuck said:


> What John said. Still trying to figure out what you are calling outriggers.
> 
> I try to avoid using screws in framing


Outriggers are short boards that in this case, are nailed or attached 90 degrees to the joists and spanning to the wall, then the ledger board is attached to the bottom and ends of the outriggers, then the ledger board is attached to studs in the wall. This would make aligning the ledgerboard to the studs much easier.


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## Cherryville Chuck (Sep 28, 2010)

Okay, thanks. Lining up the ledger board is easy. Tack a few 2x4s to the bottoms of the existing rafters and sit the ledger board on top of them. Guaranteed to be level with the rest and you don't have to hold it in place while you are trying to nail it. I wouldn't worry about the outriggers unless you are more than 2' across, which you shouldn't be. If you do need them I would cut them to length and toe nail them in after you put the ledger board up. They are mostly there to hold up sheet rock and insulation so toe nailing is more than strong enough. Unless you have 2 or 3 helpers building ledger and outriggers and then trying to install into place can be a daunting task.


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## DaninVan (Jan 1, 2012)

This is getting more complicated than it needs to be; this isn't a weight bearing wall.
There is framing, of a sort, at the edge of the drywall on the ceiling. Granted it only sticks out a couple of inches, but the original carpenters would have gone back and either used scrap or lengths of shiplap or something on top of the top plate as support for the edge of the ceiling drywall.
More than enough to fix the top plate to (screw 'toenailed').
a few pieces of fireblocking between the studs will allow you to nail/screw into the original studs wherever you can locate them.
If you're thinking of cantilevering lumber racks off this new wall then _maybe_ the extra effort with the joist blocking would be justified.


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## MEBCWD (Jan 14, 2012)

Tom,

Don't cut into the fire wall! It would be defeating the protection afforded by the special construction of that wall. 

Add the nailer to the face of the drywall with construction adhesive and nails/screws. Tack your insulation to it and mount the drywall ceiling to it.


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## DesertRatTom (Jul 3, 2012)

Thanks all for your help. I am going to simply put up a ledger board and nail it to the 2x4s underneath. I'll drive in a few large diameter screws as well. Probably won't need outriggers, although I can use something like them to make sure the ledger is parallel to and level with the existing rafters.

per your suggestions I'll have them install half inch dry wall for the ceiling. Cheap enough and we'll rent a lift anyhow. May have to extend the electric boxes the lights are in a bit, but that should be easy enough. The whole concern for me was whether or not the ledger could be installed atop the drywall, or if I had to cut into the drywall to attach it directly to whatever wood is beneath. That question got answered. I just didn't like the idea of cutting into the firewall. However, I did find a couple of holes in it from some careless past repairs, so now I'll seal them up. Thanks for that input.


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## thomas1389 (Jan 4, 2012)

Whew!! I'm glad that's overwith. What is it they say about "too many cooks" LOL.


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## DesertRatTom (Jul 3, 2012)

Actually, I liked having all the suggestions.


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## Cherryville Chuck (Sep 28, 2010)

DaninVan said:


> This is getting more complicated than it needs to be; this isn't a weight bearing wall.
> There is framing, of a sort, at the edge of the drywall on the ceiling. Granted it only sticks out a couple of inches, but the original carpenters would have gone back and either used scrap or lengths of shiplap or something on top of the top plate as support for the edge of the ceiling drywall.
> More than enough to fix the top plate to (screw 'toenailed').
> a few pieces of fireblocking between the studs will allow you to nail/screw into the original studs wherever you can locate them.
> If you're thinking of cantilevering lumber racks off this new wall then _maybe_ the extra effort with the joist blocking would be justified.


Good point Dan. A ledger board implies a weight bearing structure where all that is needed is a nailing strip.


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## DaninVan (Jan 1, 2012)

Here's a suggestion that somebody might find helpful at some point, for a partition.
Steel stud and track comes in 1 5/8" x 1 5/8" as well as the regular 1 5/8" x 3 5/8".
Three options:
Mount the top track to the ceiling (slot facing down) with construction adhesive and 1" drywall fine thread screws, installed as a toenail.
After it's set. either mount your wood studs directly into the channel, or install a wood plate in the channel first, then toenail your studs as necessary.
It.Will.Not.Move! 
The pic shows the track with steel stud, but it works just as well with wood studs. I mentioned the 1 5/8" track because you can place your studs in face out. ie a 1 5/8" thick wall instead of 3 1/2" (3 5/8") +drywall of course. You screw the studs in...don't try nailing!!!


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## thomas1389 (Jan 4, 2012)

DesertRatTom said:


> Actually, I liked having all the suggestions.


They were good. Initially, a little confusing till I got my head in the right space, but it was interesting to see all of the various ideas.


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## DesertRatTom (Jul 3, 2012)

Not sure about using the steel studs since we also have to put up drywall and wood would be easier for attaching. I'm going to mark the wall to locate the ledger board level with the existing joists by spanning a couple of joists with a board, push the board to the wall and mark the wall at the top edge of the board. I'll then locate studs and hang a few L brackets so I can have them hold the ledger board up while I attach them. I'm old and I just don't want to have to hold that thing in place by hand. We old guys have to work smart, not so hard.


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## DaninVan (Jan 1, 2012)

Tom; I think we lost contact there. "Not sure about using the steel studs"...*no, steel track, on the ceiling.* I wasn't suggesting that any one should use the steel studs with it, although that's _my_ preference when I'm doing a non-load bearing closet reno or similar.
To do the steel stud part you need a few extra tools.
Attaching the steel _track_, and wood studs to it using the 1" fine thread drywall screws is super simple. A drywall screwgun is great, _but a normal drill with a drywall screw-bit is all that you really need._ The fine thread drywall screws go through the steel track like it's butter.

The track and studs are 26ga I believe, basically just fairly light sheet metal.


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