In our garage makeover project we had to replace 3 windows. We wanted to
re-create the window trim so it would look like the original, or at least look
like the other old garages and houses in the neighborhood.
The Vinyl Window:
|One of the windows I installed was a 24" x 36"
vinyl new construction window (about $70 at Home Depot).
While this double-pane single-hung window is sort of overkill
for a garage, there really are not many options available for plain
old-fashioned garage windows.
The window installation was basic:
- Prepare the rough opening, allowing for a 1/4" gap all around.
Lay two shims on the sill.
- Apply some caulk to the back side of the window flange.
- Set the window in the opening.
- Drive one 2" roofing nail at the top right corner.
- Adjust the window position so it was level across the top.
- Drive another nail at the top left corner
- Measure the diagonals to make sure the window was square.
- Drive nails in the bottom, side and top flanges to secure the
- Smooth out any excess caulk that oozed out from behind the flange.
Carpentry On The Cheatin' Side Of Town:
I drove some deck screws into the siding, but I left the heads sticking
out about 1/8" (red arrows). This is the same thickness as the flange
on the vinyl window.
These screw heads will act as a standoff, to hold the casing
away from the wall and prevent the casing from resting on an angle.
|More screw heads at the top.
||I made a window sill from treated pine.
This was simply a piece of knot-free 2x4 that I ripped at a 10 degree
angle on my table saw.
I installed the sill with the angled surface against the wall, so the
entire piece sloped downward slightly. This will help shed water.
Note that the sill extends over 4 inches beyond the sides of the
window, to accommodate the side casing.
Of course, this sill is just decrative. In the old days the sill would extend back
under the sash (the movable part of the window).
|The window with the faker-sill attached at the bottom.
||I installed 1x4 treated pine on the sides. The lower edge of
this piece was cut at the same 10 degree angle, so it mated with the
I just nailed these boards with a 2-inch pneumatic finish nailer. Later
I added some 2½" stainless steel ring-shank siding nails, which hold
|The side casing extends to the top of the vinyl
Sometimes the best way to cut a board like this is to make the angled
cut for the bottom end, set the board in place, and mark the top cut where
the board meets the top of the vinyl.
After both side pieces of casing were installed, I installed the top
casing, also 1x4 treated pine.
Note how there is primer behind the casing. Prior to installing these boards
I scraped off the old paint in the scalloped grooves, sanded the wood clean, and
applied primer. This is just a precaution in case water gets behind the trim
someday. Primed wood is less able to absorb water.
Also, you can see some streaks of primer near the edges of these trim boards.
I primed the backs and sides of these boards prior to cutting. This is another
technique I employ to reduce the chances of water getting into the wood if the
caulking fails someday. I know from experience (and from reading) that moisture
going into and out of the wood is a major cause of paint failure. Sealing all
sides of the wood (even pressure treated wood) helps reduce moisture absorption.
I now this sounds wacko, but the extra time involved is trivial.
|I nailed on the top cap. This is a piece of clear,
straight-grained 1x4 treated pine that I ripped on my table saw, with a 10
degree angle on both edges.
I sanded all surfaces with a random orbital sander, and slightly
rounded-off the corners so they wouldn't be so sharp.
|The completed casing, ready for priming and painting.
Case 2: Aluminum Window, Full Sill
||The east side of the garage, before the makeover. Those
windows have been boarded up for years.
|One of these windows wasn't even installed straight. All we
could figure was... the original carpenters must have drank a lot of
liquor at lunchtime... nothing else could explain this pathetic
||On the inside I pried off anything that looked related to
the original window installation.
|On the outside I carefully pried off the trim, thinking that
I might want to reuse it.
||I pried away the casing a bit and cut the nails with my
|The casing was removed easily.
Only the original window sill remained. I decided to reuse the sills on
these two windows
||I pried on the sill to see how it was nailed in place.
They had nailed through the vertical face of the sill, into the studs
on either side of the window.
|I removed the paint from around the window opening. I used
the Metabo power paint remover for the flat surfaces, and a scraper for
||After the sill was stripped and sanded, I installed two
angled blocks for the sill to rest on. I was careful to make sure that the
sill would end up level, because the window will rest on this sill.
These were just 2x6 scraps cut at a 10 degree angle and screwed onto
The sill had not been fastened down yet.
|I coated the back sides of the sill with primer, installed
it, and then painted the remaining surfaces with primer.
I also dabbed some primer on the bare surfaces around the window
opening. Just in case.
||I installed the window.
After applying a bead of caulking all around the back of the flange, I
just set the aluminum-framed window into the opening, resting it on the
I installed one screw in a top corner, then I measured the diagonals to
make sure the frame was square.
Then I drove in screws all around the perimeter.
|Where possible I used screws with a low-profile head, so
they wouldn't interfere with the casing.
Note how this metal window frame has a channel shape. This may be
intended to act like vinyl siding J-channel, to cover the ends of vinyl
I also caulked all the gaps where the scalloped part of the siding met the
window flange. This will deter leaks and discourage bugs from nesting in there.
||Using a brad nailer, I attached some 1/4" thick strips
of wood around the perimeter of the window.
These are spacers, but they will also be visible, so I laid them out
carefully so they would line up with the edges of the 1x4 trim boards.
|I installed the side casings and then the top casing.
||The bottom end of the side casings were cut at a 10 degree
angle to match the window sill.
There were some small pits in the old sill, which I later filled with
polyester resin (essentially Bondo) followed by the final coat of paint.
|I installed the top cap.
(Okay, I cheated... this picture is from the other window, but it's the
Where Siding Meets Casing:
||I applied caulking all over the place, especially between
the window frame and the wood casing.
||The red arrows point to seams that I later caulked with
siliconized acrylic latex caulk.
The top seam is critical. Ideally I would install an aluminum
Z-flashing over this gap, with one leg of the Z-flashing going under the
next higher siding board.
But... that wasn't possible.
|Where the scalloped siding met wood trim, I applied a
liberal dab of caulk and smoothed it with my finger. But often one
application isn't enough.
|I just let the caulk harden for an hour and then applied
more to fill in any holes.
||The completed project. These are the two aluminum windows
that I installed over the original sills.
|That's the vinyl window with the fake sill, to the right of
the red door. It's a bit bigger than the aluminum windows.
Some notes about using treated wood:
Pressure treated yellow pine is an inexpensive and very durable wood. If the
paint ever fails, I'm certain the wood will last many years before it begins to
rot. But treated yellow pine is a tricky material to work with, especially for
finish carpentry, because it can warp very badly. They don't call it
"Banana Wood" for nothing.
Since pressure treated wood is soaked in a water-based chemical solution, the
boards are often very wet when purchased. Boards that appear straight at the
store often look like hockey sticks or airplane propellers in a few
Thin lumber can usually be forced to lay flat, and it will stay there if
fastened well. I don't consider common nails to be good fasteners. Ring-shank
nails or deck screws are good fasteners for holding warp-prone wood in place.
But my usual approach is to just be lazy. I often buy the materials
far ahead of time and store them in a warm, dry place. It always seems to take a
couple of weeks longer than planned before I get around to using the wood, so
the wet pine ends up drying out. If the wood is going to warp, it will warp
while it's drying in my shop. Then I can choose the best boards for the most
critical trim pieces. Of course, this means that I usually need to buy extra
materials, because some boards won't be usable for visible trim, but even the
worst boards get used somewhere.
Yes guys, there is a good side to procrastination. Letting the lumber
dry makes good sense.
Back To Top Of Page
- Cordless Drill/Driver
- Basic Carpentry Tools
- Miter Saw
- Table Saw
- Finish Nail Gun
- Lumber, Pressure Treated, 1x4x8'
- Lumber, Pressure Treated, 2x4x8'
- Ring-Shank Siding Nails
- Deck Screws
- Siliconized Acrylic Latex Caulking
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