An Old Fashioned Window Frame photo by Seemann
Smart Tips for Easier Installation of a New Window
Whether retrofitting your home to modernize the functionality and efficiency of living areas, doing unavoidable repairs, or remodeling for aesthetic reasons alone, your project may require the replacement of windows.
Perhaps decay, leaking or shrinking sashes, or broken panes are pressing problems. Old-fashioned windows may be too small, out of style, or you may desire more energy efficient windows. Replacing windows becomes more challenging as styles change and popular sizes become out-dated. Both materials and methods of construction may have substantially changed since the original windows were installed. In spite of change, you can install a new window using basic carpentry tools, common sense and a few tricks of the trade.
To install a new window, you will Need a few essential tools such as
- tape measure,
- a small pry bar,
- carpenter’s hammer,
- hand saw,
- a pair of pliers and diagonal cutter.
- ladder or scaffolding as required
For supplies, to install a new window unit, you may need
Here are a few handy tips for planning and installing a new window with as little trouble as possible.
1. Remove the interior trim first.
- a few cedar shims
- silicone calking,
- wood screws and fasteners will be required, depending on the method required to secure the new window in place.
Removing the interior trim exposes both the window frame
and the wall-framing
, enabling you to measure it very accurately without disturbing the existing window installation
. To measure from the exterior requires the removal of the “brick mold” which in older installations, holds the window in place
. You may have to wait a couple of weeks or longer to obtain delivery of that new custom-sized replacement unit. It is preferable not to loosen or remove the old window before you have the new one on site
, but you still need accurate measurements. The smart and logical solution is to measure initially from the inside.
To expose the window frame and wall framing, remove old, unique, heritage, or fragile interior trim wood very carefully.
You may decide to replace it with a new updated trim profile, or simply upgrade the trim to a higher quality.
To remove old trim without damage
, use one of the amazing modern slim pry-bars; slide the razor- thin edge carefully under the back of the trim and pry gently, using a pry block to prevent any damage to your interior wall.
If you plan to re-use the trim,
pull the old finishing nails right through the back of the wood trim using diagonal cutting pliers instead of trying to hammer the fasteners back out through the finished surface. Alternatively, you can cut the old fasteners off, leaving the head and a very short section of nail in the wood. Using either method, you will avoid splitting or shredding the visible, brittle surface of the old trim. If the nails were set deeply and filled correctly when the window was originally trimmed, tell-tale nail holes from the old fasteners will not be visible. You can then maintain the original finish, or choose to refinish the trim as required
2. Measure the window frame
Take time to measure the outer dimensions of the window frame very accurately.
*For the neophyte, the window frame is the structure the sash and glass
are mounted into. The window frame unit
is mounted in the wall framing "hole-in-the-wall"
Check to see if the old window frame is square.
Record this measurement and note the window design
, whether the window is a fixed unit
, a vertical opener,
a horizontal slider
, or a hinged French opener, and note which side a swinging window with special opening hardware is hinge-mounted.
3. Measure the “hole in the wall”
With the interior trim removed, you can see the edge of the wall framing. Measure the frame dimensions of the “hole in the wall”. Make a special note if the framing is not square
, to allow for any error. Make a diagram of the measurement to take with you to your building supply store.
*Measure the thickness of the wall to ensure your new window will have an adequate jamb width, if you will need to customize jamb extensions
. Jamb width of the new unit must be extended to be flush with the wall framing.
4. Choose your new window
It is essential to order and obtain the new window before you remove the old one. It may take several weeks or longer to obtain a special order, custom-sized window unit.
When selecting a window, choose the style you want and ensure the outside frame dimension of the new window unit is approximately one inch smaller in both dimensions than the “hole in the wall” measurement, or equivalent in size to the outer dimensions of the old unit. A half inch of space all around the window frame is desirable for adjustment and the insertion of adequate insulation when you reinstall the new unit.
*As an aside, if there is no standard, “close enough” or “in-stock” size and styl
e of window available that will fit in the opening satisfactorily , you are left with three choices:
- The first, and best choice, to avoid framing changes, is to have a window custom-built to fit the existing hole in the wall. With the business of home renovation booming, there are window manufacturers that specialize in custom-sizing window frames to every window dimension imaginable. Avoid measuring mistakes and extra expense; always double check the measurements . Custom-sized windows are not usually returnable if the customer has erred in measurement. Specify the type of glass and trim when ordering. Consider “low-E” glass sealed units for energy savings.
- The second choice is to install a smaller window; just fill in the framing using standard framing techniques as required.
5. Removing the old window
- The remaining installation choice, a popular method, but also a much bigger job, is to re-frame the window opening for a modern and even larger size, which can be a complex job, especially if the window is large and the exterior wall is load-bearing. Particular care and attention must be paid to ensure standard framing practice is used if a longer window header must be installed.
To remove the old window, caution is required. Work from the outside and carefully score and cut away any caulking from the window trim, brick or stucco. If the exterior wall is stucco,
run a small circular concrete-cutting blade in a hand-held grinder along the stucco-wood joint, outlining the edge cleanly to ensure a clean separation and avoid unnecessary and random cracking of the stucco.
Note: Observe How the Original Window was Installed
It is important to keep in mind that in most standard window construction, window frames were installed into the wall by fastening the window trim or brick mold to the exterior wall.
For traditional construction of window units, the exterior trim ('brick mold') was attached directly to the window frame when the unit was built
. Brick mold can be separated from the window frame with enough effort, but in doing so, the window may be sitting completely unsecured and can fall out. Remove the window including the exterior trim or brick mold as a unit.
Pry out the “brick mold” keeping in mind the window will follow, may detach if the wood is decayed, and will require immediate support.
*Caution:To be safe, approach the job of prying the window out carefully. A used window may be recycled if it is in decent shape. Remove the old window carefully and store it for disposal. Remember that old glass, usually not tempered, may create very sharp, dangerous shards if broken. The long “finishing nails” or fasteners that typically hold the window brick mold in place can be pretty sharp and rusty.
Note: *Use gloves, safety glasses and protective clothing. Always follow power tool safety protocol and have help available to lower large, heavy windows to ground level safely.
6. Preparation of the “hole in the wall”
If the framing is a suitable dimension, remove protruding nails from all surfaces of the framing and inspect the wood for decay. Check for insect damage such as termites if they pose a problem in your geographic location, and always replace damaged or rotten wood framing members as required.
If your replacement window is not identical in size
but the framing remains solid, fill in the opening appropriately with dimensioned lumber or re-frame the hole-in-the-wal
l to the new dimensions as required.
Remember to include that one-half inch of space all the way around the new window frame required for squaring, leveling (horizontal) , plumbing( vertical) and insulating the new window.
Install a new strip of waterproofing felt paper or a breathable membrane
(commonly called “house-wrap”) around the rough window opening. If using pieces, place the bottom or sill piece in first, running it up the sides several inches. Ensure the wrap is wide enough to extend onto the outside wall two inches, and an inch inside. Staple the paper in place neatly.
The paper or membrane acts as a waterproofing keeping water out of the wall framing. At the top of the window on the exterior, tuck the waterproofing strip under the existing flashing, siding or stucco.
7. Installing the new window unit
Depending upon the size of the window, lay support blocks or suitable cedar shims on the frame sill to rest the window upon when you insert the window unit from the outside.
Place the large end of the shims on the outside, with the long thin ends protruding on the interior. You will use those to slide in opposing sets of shims (large end inside) in the same position
to level the window when it is in place.
- If the new window has a “flange” around the exterior edge as many vinyl-clad windows now do, you will require a tube of silicone caulking. Run a bead of silicon on the exterior wall around the window to seal the flange to the wall.
- Insert the window carefully and secure it while you insert additional shims to level the window frame. Center the window in the framing initially, and use a carpenter level to ensure it is both plumb and level.
- Install shims on the sides as necessary and fasten the shims in place with a small finishing nail through the jamb if necessary to ensure they do not drop out.
- If the window is sitting correctly, fasten one side loosely with screws and re-check it.
- Fasten all of the flanges adequately using appropriate screws, forcing the flange into the silicone bead. Remember to measure diagonally across the corners to ensure the window is square! * Hint: Some window frames are imperfectly manufactured. Cheaply-made frames are somewhat flexible, and may shift out of square in spite of the fact they have glass units installed in them. Correct your unit to square. If the unit cannot be squared, it is defective. Insist on a replacement. It is critical to have the window square, level, and vertically plumb, particularly if it is an “opener” style, whether a slider or hinged .
8. Finishing the Interior
On the interior, trim any shims flush
- Install additional exterior trim or “brick mold” in place as required.
- Install an adequate metal or vinyl flashing over the top brick mold if required.
- Caulk the exterior joint where the siding, stucco or brick is adjacent to the trim.
- Fill the holes, sand and paint , using exterior primer and paints.
that may be sticking out.
- Insulate the window space between the waterproofing strip and the window. If you use mineral wool or fiberglass, avoid packing it too tightly, as packing insulation too densely defeats the purpose of insulation. If you choose to use expanding foam instead, take all recommended safety precautions, including wearing vinyl gloves and goggles. Apply the foam judiciously and allow it harden fully before trimming it off flush with the wall framing.
- Neatly fold, trim, and staple the waterproof strip onto the wall framing.
Coffee time! Now that you know how to install a new window or replace an old, defective window, you can use the same skills to install that beautiful sliding patio door too!
Is that Incoming I hear?
- Re-install the old interior trim with finishing brads, or custom-fit new trim. Sand and fill the holes, use interior primer, and stain or paint the window and trim to the desired colour.