I just moved into a new house that has a huge attached garage. The rear
area of the garage
(apprx 700 ft^2) already has piping in the floor to heat that area.
The previous owner never got
around to finishing this workshop area, and this is now my #1 priority.
I have already added outlets every 10 feet or so, including 220
circuits for air compressor
and welder. (i do some metalworking as well...) I just insulated the
walls with R13 with the
vapor barrier backing, and now I am wondering what to put on next.
sheetrock, or osb???
The wall between the house and this back area of the garage is already
insulated and drywalled,
and I am wondering if i need to continue drywall all the way around for
(since it is an attached garage, if it burns down, the whole house
could go up???)
Another point is that i am planning on using a small woodburner in
there to heat the area,
plus heat up the glycol that i will be pumping into the floor.) I
wouldn't be so concerned
about fire safety except for this point.
I would prefer to do OSB for cost and ease of hanging anything
anywhere, and I have
read the several other posts about this topic, but there hasn't been
about osb vs. drywall from a fire safety point of view.
Also, is there any code requirements about what to use in an attached
Any help would be appreciated.
No expert but my understanding is that the fire rating is only applicable
between the garage and the main house. What you do on the outside walls, not
adjacent to the house, is of no code consequence. As for safety, yes, OSB
will burn more readily than drywall. Not really a worry IMO. Just make sure
you observe minimum clearances to combustibles for your stove and that you
have a safe area to do your welding. I like the idea of sheathing the walls
in wood. It make it very easy to hang stuff. Just drive a 16d nail and hang
up a coiled extension cord. No worries. paint it and things will really
brighten up too. Ply is more expensive than OSB but if cost is not a factor
would be my choice.
I would consider T1- 11 instead of OSB. T1-11 is plywood with a rough sawn
face veneer and would look much nicer. As far as fire safety is concerned,
I think (without any scientific facts) that drywall would be less prone to
burn than wood. You may want to drywall around the area where your putting
the wood burner, (or stone, brick, etc) and do the rest of the walls in
Heartily agree with this. It's what I chose and it has been great. OSB is
functionally as good, but unless you paint it it will look shabby IMO. On
the other hand, if you want to paint it white for better lighting, then why
not OSB? For me, a woodshop should have wooden walls.
No drywall, except where code requires.
You would be better off by far to drywall the ceiling. Once a fire gets
into the attic of a structure, It becomes almost a lost cause. 5/8"
drywall finished, tape and mud. Don't leave any screws exposed or any
cracks through to the attic space. You'd be surprised how much heat a
screw can transfer into a piece of wood. Likewise, you would be
surprised how just a little drywall compound can shield heat from a
Do you think you should talk to your insurance agent? If your shop
catches fire and burns your house down, the woodburner will probably
still be standing there in the middle of all of that ash. That will be
a terrible time for you to discover that you may have violated the
terms of your policy. They're _LOOKING_ for a way _out_ of paying
claims. Maybe an outdoor boiler would be better, you already have the
plumbing in the floor.
Tom in KY, It looks obvious to me. And by the way, I'm sooooooo jealous
that you found a shop space wih the plumbing already in the floor. You
have such a real neener-neener there!
I do metal working as well.
And in several shops that I have seen and worked on, we were fanatics about
fire safety. We put up cement blocks as a firewall/barrier. It did not
cost that much and everybody from the fire inspectors to the insurance guys
were very impressed.
Not the whole place mind you. But where the house joins the garage. Also,
I would seriously consider walling off with cement blocks any welding area
from the woodworking area. I have had sparks fly into woodchips. The
combustion was quick and took my entire fire extiguisher to put it out.
While OSB is cheaper...it is ugly beyond compare. I would use
3/8" plywood called "rough tex" or "rough sawn". It will take
paint quite well and the looks will be waaay past OSB.
T-111 would be another decent choice.
I have never seen a OSB wall that didn't look like OSB no matter
how great the paint job.
It sounds like T1-11 is the way to go. I have never heard of the
stuff, although i probably have seen it before.
Can I get it at Home Depot, and about how much is a sheet?
Drywalling the ceiling is another problem I haven't tackled yet. The
framing spacing is 24" and I figured
that drywall would end up warping and sagging after a few years. Also,
I would have 12' ceilings and it
is going to be a pain to put anything up that high. (i've seen other
posts about renting one of those
The original owner / builder of the house has the floor plumbed with
the pipes going into my basement.
It looks as if he was going to put a gas water heater down there to
heat the floor water with.
That is great and all, but I would rather have free heat in the form of
wood than pay huge gas bills.
Also, I already have the wood burner built (my father and I built one
for his smaller woodshop, only to find that
it was too big and way too hot in there, so he built another smaller
one, and i was planning on taking the
the insurance thing kinda worries me too. I tried calling my insurance
people, but they didn't seem
to understand what I was talking about at all ("you want a fireplace
in your garage???").
I guess that is what happens when you use one of the huge insurance
I used OSB on all of the walls in my shop and have been quite pleased
with it. I was prepared for some smell after installation but never
really smelled much of anything (mine came from one of the borgs).
The natural "woodchip" look really wasn't a problem and looked kind of
good in a workshop, IMO. But I did paint it to brighten the shop up.
Just be aware that you must prime it and be prepared for it to suck up
the first coat. Also, due to the texture, spraying the paint would be
preferable if possible to get into the nooks and crannies, but not
It is very solid stuff that is easy to hang anything on anywhere. It is
more solid than the T-111 I'm familiar with.
24" centers is a building standard. 5/8" drywall will not sag
noticeably unless you have a serious humidity problem. No whining about
12' ceilings. Your gloating makes me sick :-)
I have done repairs for a major carrier in this area off and on for
years. I like having a local office agent. Did the big company even
send you a copy of the policy? I rarely do repairs after fire damage.
Fire damage falls under a whole different set of rules.
Good luck with it.
12' ceilings too high to be comfy while installing drywall?, (can I
steal a line from 1369?) BWA-HA-HA-HA-HAAAAA,
Tom in KY, with low ceilings in the shop < 8', BWA-HA-HA-HA-HAAAAA.
There is special ceiling drywall available in all standard sizes. Cost a
little more, weighs a little more and is a lot tougher. Will not sag because
that is what it is made for.
Get a panel lift, but check first many will not go to 12 feet. A rental
scafold , a couple of friends and some liquid rewards after the job is done
and it will be done before you know it.
Good luck and nice space.
I used OSB on mine mainly due to:
- ease of removal should it ever be necessary,
- hard to poke a hole in it when I get clumsy,
- easy to hang small tools and shelves on when necessary,
- easy to paint (primer then bright white).
I've not regretted using OSB in the least!
I seem to be the odd man here, but my shop walls are sheet rocked, taped and
textured. I have a friend that has his shop finished of with OSB. I like
mine better! As far as hanging up stuff, plenty of studs to screw to, so I
can't see any benefit there. Plus OSB does not hold screws that well anyway.
I would go with sheet rock again, no question.
About 3 years ago I insulated and sheathed the inside of my shop with
OSB, using 2 layers of3" Styrofoam underneath for insulation with a
vapor barrier of 6 mil underneath that. My rationale for the OSB vs
dry wall was durability and moisture resistance. I finished the seams
of the OSB using drywall mesh and joint compound. in the styro foam
seams I used spray foam to seal/bond them together. The end result
was a very weather tight inside that appeared to be drywall, but
wouldn't "dent" or "puncture" if you accidentally rammed it with
something. The shop had metal siding (pole barn) 24'x36' 12' ft eaves
with two 10'x10' roll up doors and a regular size door entry with a
insulated storm door. The roll ups were also insulated, replacing the
original sliding single door which was impossible to get a good
weather seal on during the winter. The ceiling was prepared in a
similar way except no drywall compound was used. Before beginning the
insulation job I removed all of the existing light and power wiring
and would reinstall surface mount conduit after the installation of
the insulation. I finished the floor with Pittsburgh Paints Epoxy
paint to finish the interior upgrade. I was switching from T12x48"
dual fluorescent fixtures to T12 x 96" dual fixtures and was in the
process of laying out the best points to hang the fixtures for the
best use of the light and was awakened the following morning by
dampened THUD! sounds not unlike what a pile driver produces,
including the feel of the thud through the ground and I was inside my
home on the second floor.
The mystery sounds turned out to be my oxy/gas, and propane tanks
exploding inside my shop. The single power plug I had remaining had
been plugged into a drillmaster 14.4v drill battery charger the night
before and had evidently caught fire, catching the OSB, Styrofoam and
everything else on fire. When I discovered it the walls were still
standing however the fiberglass skylights in the roof had burned
through (all six of them) and were "boiling" out dense black smoke. I
knew then that it was too late and everything was toast at that point.
Luckily my shop was a detached building and was 10' from the house at
the closest point, it did however severely blister the house paint in
that area. I had welders, plasma cutters, router duplicators, three 5
hp air compressors I had just built on 60 gallon tanks that had never
even been powered up yet, couple of shopsmiths, table saw, and bunches
of hand tools and lots of handscrews and bar clamps, last but not
least, there was about 25000 board feet of 4-5" thick black walnut
slabs I had "stickered" and had been air drying for 1 1/2 plus years
in a loft that covered half of the shop. I am about ten miles from
the closest fire station up on a fairly steep hill (ever see how SLOW
a fire truck full of water goes up a hill?!!)
The firefighters basically just caved in the metal shell when they got
there and soaked down the burnt debris inside left on the floor slab.
There was charred debris about 2 feet deep over the entire interior.
SO, having said all that, what do you think I might recommend for
interior sheathing? Is it OSB or Drywall? Needless to say I will
NEVER use OSB in an application like that again, unless the structure
has automatic fire sprinklers installed and there is a standby power
source in case utility power is lost for some reason. ( I am
convinced that the catalyst that started the drill charger burning was
a large power surge in the first place!) Interestingly enough the guy
from the power company was first on the scene I found out later, and
NOT the meter reader guy whom I would have recognized. I assumed he
was the fire Marshall who drove up in his own rig to get there first,
he didn't identify himself until the lead fireman asked him "who are
YOU?" he replied: "I work for the power company.." Otherwise I
might still think he was with the fire company in some sort of
Yes, my house now has as will my new shop heavy duty surge suppression
installed in the distribution breaker box, along with a dual power
fire/smoke detection system that is all networked together, and I am
seriously considering overhead sprinklers for the shop at least. If I
go with a conventional metal sided pole barn the inside will use
fiberglass insulation and sheathing will be "green" drywall for
moisture resistance with Tyveck or similar house wrap as moisture
barrier next to the metal siding of the outside walls. I am seriously
considering a new wall system invented by Dow Chemical that uses a
4-6" foam core with wire mesh on both inside and outside walls that is
then sprayed with a high strength liquid concrete, similar to gunite.
Another possibility is to use standard concrete "Tilt-up" walls that
are cast in forms onsite.
One small ray of shining light in the whole mess was that the
stickered walnut in the shop loft was so thick that about 1/4 of it
will be salvaged. when the loft collapsed the walnut planks got
buried by everything else and given the thickness of the slabs only
burnt about 50% of the wood in the middle of the stack.
The short answer to your question is: My vote is for the drywall.
Good luck, best regards and happy new year, Joe.
How about Hardie Board siding? They come in 4x8 sheets in several patterns
and colors. Color-matched nails are available as well. It would be as easy
to install as the OSB, but a whole lot better looking. Probably twice as
expensive, though. And I would think their fire resistance would be much
higher than either OSB or sheetrock. They also make 4x8 sheets of soffit
that you could use in the ceiling.
Just something else to think about,
As noted in another message, fire code sheetrock is only required on the
wall between the garage and house, and on the ceiling if a common roof with
open space between section over garage and house (i.e. no firebreak)
I did my shop in Plywood. Not the most beautiful material, butr gives a
warm feeling and as noted makes mounting stuff very easy.
One big suggestion, run the ply horrizontally with a section in the middle
that is removable. Put all your wiring in this area. That way if you need
to get to wiring to add or change an outlet , or do other electrical
upgrades everything is accessible!!
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