Michigan State University Extension
Home Maintenance And Repair - 01500181
06/24/03
Caulking Windows
Unfilled gaps and cracks in the foundation, around
windows and doors, vents, and so on, may let cold air in
the same as leaving a window open.
In fact, a 1/8 inch opening around just two door
frames can let in as much cold air as a 12 inch window
opened 6 inches all winter long.
Caulk is used around outside window and door frames,
and to fill outside wall and foundation cracks.
The money you spend on caulking or weatherstripping
is usually recovered in one heating season or less.
This one season "pay-back" period means that money for
heating fuel is saved equal to or greater than what you
spend for caulking and weather stripping materials.
1. A clean joint is the first and most important step.
Clean away all old caulk and loose paint or dirt and
apply new caulk to dry surfaces. The most common and
easiest to use caulking comes in cartridges for which you
will need a caulking gun. A good rough estimate is that
you will need 1/2 cartridge per window or door, 4 for the
foundation sill, and at least 1 more for around faucets,
vents, pipes, electrical outlets and so on.
Cut off about 1/2 inch of the cartridge tip on a 45
degree angle and puncture the tip seal with a nail. You
can use the nail later to act as a stopper for any unused
caulk. With a little practice on a joint that's not
visible you'll soon be able to lay a uniform wide bead
that overlaps both sides for a good seal. Finish the
surface with a moistened finger if you like but that's
not necessary. Remember to use a filler, like oakum, for
wide joints before you caulk.
Some but not all the places you should look when
surveying you home before caulking are around doors and
windows, dryer vents, faucet pipes and wires, where
porches attach to the house, seams between masonry and
siding, chimneys and inside corners.
This article was written by Anne Field, Extension
Specialist, Emeritus, with references from Michigan
Extension bulletin Caulking and Weatherstripping.
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
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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
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