Michigan State University Extension
Home Maintenance And Repair - 01500161
06/24/03

Replacing Broken Window Glass


Broken window glass can be replaced by regular glass
or by plastic unbreakable glass.

Before starting to replace broken glass, put on a
pair of gloves and a pair of glasses. It is easy for
bits of glass to chip and fly.

Glass, in both wooden and metal frames, is held in
place usually by a mechanical fastener. Putty or glazing
compound is then applied to keep out rain.

The following steps are suggested for replacing
broken window glass:

Step 1.
Carefully remove all pieces of glass being careful to
clean up the area around the window to prevent injury
and cuts. Use pliers to grip pieces of glass still in
the window.(Vis. 1)

Step 2.
With a chisel or jackknife, remove the old putty. Be
careful not to gouge the wooden frame. As you proceed
around the frame you will find glaziers points (small
steel triangles) in wooden frames or spring clips in
metal window frames. Save these points or clips. Be sure
all old putty is removed so the glass will slide into
place easily.(Vis. 2)

Step 3.
With sandpaper or a rasp, clean off bits of putty which
might remain on the wood or metal sash. (Vis. 3)

Step 4.
Paint the frame with linseed oil, wood preservative, or
an oil base paint. This seals the wood surface under the
putty and prevents the metal frame from rusting. A fast
drying paint is most convenient.(Vis. 4)


Step 5.
Measure the size of the glass with a yardstick or
folding rule. A steel rule may sag causing errors in
dimensions. Allow 1/8" clearance on all sides so reduce
each measured dimension by 1/4". Buy the glass cut to
the correct size.(Vis. 5)

Step 6.
Put a thin ribbon of glazing compound in the groove on
the frame for the glass to rest on. Keep the thickness
of this glazing compound fairly uniform so when you press
the glass down into the compound it will not crack.
(Vis. 6)

Step 7.
Install the glass, press it onto the glazing compound and
insert the glaziers points (small metal triangles) which
you removed. Push these in with a large screwdriver. If
you use a hammer be careful not to break the glass. The
points should be placed every 6" to 8". The spring clips
for metal windows should be inserted in the holes
provided in the steel frame.(Vis. 7)

Step 8.
Knead the glazing compound and form it into strings no
bigger than a pencil. Lay a string of compound along one
side at a time and force it onto the glass and wood frame
with the tip of a putty knife. Smudges from the compound
can be removed later with a cloth dipped in turpentine.
(Vis. 8)

Step 9.
After the glazing compound has dried, paint it to
finish sealing the seams between the glass and the
compound, and the wood and the compound.(Vis. 9)

This article was written by Anne Field, Extension
Specialist, Emeritus, with references from Michigan
Extension bulletin Replacing Broken Window Glass.

Go To Top of File        Michigan State University Extension Home Page        Main Page for this Data Base
This information is for educational purposes only. References to commercial products or trade names does not imply endorsement by MSU Extension or bias against those not mentioned. This information becomes public property upon publication and may be printed verbatim with credit to MSU Extension. Reprinting cannot be used to endorse or advertise a commercial product or company. MSU is an affirmative-action, equal-opportunity employer. Michigan State University Extension programs and materials are open to all without regard to race, color, national origin, gender, gender identity, religion, age, height, weight, disability, political beliefs, sexual orientation, marital status, family status or veteran status. Issued in furtherance of MSU Extension work, acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture. Thomas G. Coon, Director, MSU Extension, East Lansing,MI 48824. This information is for educational purposes only. Reference to commercial products or trade names does not imply endorsement by MSU Extension or bias against those not mentioned. This file was generated from data base 02 on 02/04/08. Data base 02 was last revised on 06/24/03. For more information about this data base or its contents please contact strausc@msu.edu .