Add blocking and framing
Most rough-framed garages aren’t
ready for drywall. Your garage may
be missing studs at the corners and
attachment points for the ceiling drywall.
To see where framing members
may be missing, inspect inside corners
where walls meet and where the
walls meet the ceiling. These are the
most common areas needing additional
framing. These two photos
show how to add ceiling blocking.
While the framing is accessible
and you have your carpentry tools
out, you may want to add other framing
or structural elements. Here’s a
list of possibilities:
- Add blocking between studs
for attaching shelving.
- Nail blocking between ceiling
trusses for hanging
lights, cord reels or bicycle
- Frame an opening for an
attic access hatch.
- Frame a ceiling opening for
a drop-down attic ladder.
- Cut a hole and frame an
opening for a through-the-wall
- Add windows or skylights.
Turn off power before working on wiring.
Reroute wiring and add outlets
Most unfinished garages have the bare
minimum of outlets and lights, so
you’ll want to add a few. And in some
cases, you’ll have to reroute wiring
that’s attached to the face of studs or
the underside of ceiling framing. We
had to reroute phone wires, door
opener control wires and plastic-sheathed
cable in our garage. Remove
surface-mounted wiring and move it
into the stud space, or reroute it over
the top of the ceiling joists or trusses.
You may have to drill holes through
studs or through the top plate of walls
to reroute wires. If so, be sure to center the holes on the stud. If the
plastic-sheathed cables are too short
to reach the next box when you
reroute them, you can add a junction
box and splice on a length of cable.
The new box must be accessible
either in the attic space or through a
blank cover on the wall or ceiling.
This is also a good time to add outlets,
lights and even another 20-amp
circuit for power tools. Figure A shows
some wiring improvements to consider.
Call the local building inspections
department to get a permit before you
add or change wiring, and have the
wiring inspected before you cover it
with drywall or insulation. Not up for
doing the wiring yourself? Extra outlets
and good lighting are well worth the cost of hiring an electrician.
Figure A: Plan Your Electrical Needs
Figure A: Plan Your Electrical Needs
Draw a sketch of where work areas, appliances and electrical devices will fit before beginning the wiring.
Ventilate and insulate
An insulated garage will stay cooler
in the summer and warmer in the
winter. The first step is to be sure the
attic is well ventilated. Check to see
how many attic and roof vents you
have. A good rule of thumb is a total of
1 sq. ft. (144 sq. in.) of vent opening per
300 sq. ft. of attic divided between the
soffit and roof vents. For a typical 20 x
22-ft. garage, you’d need about six 4-in.
x 12-in. soffit vents and two standard
square roof vents. Make sure your ventilation
is effective by installing vent
chutes between the trusses.
Vent chutes have a channel that prevents
blown insulation from blocking
the airflow from the soffit vents to the
attic space. Plug the area under the
vent with wood blocking or plastic and a chunk of fiberglass insulation
to prevent wind from blowing up through the insulation or insulation
from filling the soffit.
We recommend filling the stud
spaces with friction-fit fiberglass
batts, covering the walls and ceiling
with a 4-mil poly vapor retarder, and
blowing insulation (cellulose insulation
is a good choice) into the attic
after the ceiling drywall is installed.
Start by insulating the walls. Buy
unfaced R-13 batts for 2x4 walls and
unfaced R-19 batts for 2x6 walls.
Match the width of the batt (15-1/4 in.
or 23-1/4 in.) to the stud space. Cut
batts carefully for a tight fit. Next, staple
4-mil poly to the walls and ceiling.
Embed the poly sheeting in caulk
around the perimeter of each piece to
create an airtight seal. Seal the seams
between sheets and seal the poly to
electrical boxes with caulk or special
sheathing tape (it’s typically red and
looks like packing tape).
After the drywall is installed on
the ceiling, you can blow insulation
into the attic. Home centers and
some rental stores sell blow-in–type
insulation and often offer free or
reduced rate rental on the blower if you purchase insulation from them.
Weather-strip doors and windows
Leaky doors and windows let in
uncomfortable drafts and increase
heating and cooling costs. Check
your garage service door to be sure it
has good weather stripping and a
threshold that seals tightly to the
bottom of the door. In most cases, if
your service door is missing a
threshold and weather stripping, it’s
more efficient to replace the door
with a new, weather-tight version.
You can buy an inexpensive prehung metal
exterior door at
home centers and lumberyards.
The overhead garage door can be a
big source of drafts and heat loss.
Recently installed doors usually
include a weather-stripped stop
around the perimeter. But older
doors may be lacking a weather
strip. Luckily, it’s an easy fix. Garage
door weather stripping is available
at home centers and hardware stores, and installation is straightforward. If your overhead
door is uninsulated, search online for “garage door insulating kits.”
Back to Top
Finish up with drywall
Drywall is the easiest and most economical
covering for your garage ceiling.
Use 5/8-in.-thick drywall if your
trusses or rafters are spaced 24 in.
apart. We’ll show you a few tips to
simplify drywall installation.
Before you install the drywall,
temporarily remove the brackets that
support the garage door tracks and
opener. This will make it easier to
install the 4-mil poly and ceiling
drywall and will result in a neater-looking
job. Start by carefully measuring
and recording the position of
the tracks and opener. Measure from
the nearest wall and from the floor.
Then close the garage door, lock it
closed and unplug the opener to disable
it. Unscrew or unbolt the brackets
that support the garage door
tracks and remove them. Also
remove the garage door opener
brackets and support the opener on a
ladder. It may be easier to entirely
disconnect the opener and set it
aside. Reinstall the garage door track
brackets using a new section of angle
iron on the ceiling. Attach each new
ceiling angle iron with four 5/16-in.
x 3-in. lag screws driven into the
center of the ceiling joist or into
wood blocking that’s screwed to the
adjacent ceiling framing.
The second tip that’ll simplify the
drywalling job is to rent a drywall
lift. They’re available at
most rental centers. For ceiling work, load the sheet
onto the lift vertically and then
swivel the lift platform until the
sheet is horizontal. Then crank the
sheet to the ceiling while you roll it
into position. The lift also works for walls.
DIY Success Stories
The smartest thing I did in my garage was to add lots of outlets. I put them high on
walls, low on walls, even a few switched outlets in the ceiling to power plug-in type
fluorescent lights. Fourteen outlets in all! My wife thought I was nuts, but I’ve never regretted it. No matter what I’m doing, easy-access power is right there.
I covered my garage walls with 5/8-in.
OSB instead of drywall. It costs more
and doesn’t look quite as good. But it
looks fine with a few coats of paint,
and I didn’t have to sand drywall mud
(which I hate!). Better yet, I can
mount pegboard, brackets or hooks
anywhere. No need to hunt for studs.