by Nick Gromicko, Rob London and Kenton
Winterization is the process of preparing a home for the harsh
conditions of winter. It is usually performed in the fall before
snow and excessive cold have arrived. Winterization protects
against damage due to bursting water pipes, and from heat loss
due to openings in the building envelope. Inspectors should know
how winterization works and be able to pass this information on
to their clients
Water damage caused by bursting pipes during cold weather can be
devastating. A ruptured pipe will release water and not stop
until someone shuts off the water. If no one is home to do this,
an enormous quantity of water can flood a house and cause
thousands of dollars' worth of damage. Even during very small
ruptures or ruptures that are stopped quickly, water leakage can
result in mold and property damage. Broken water pipes can be
costly to repair.
- All exposed water pipes in cold areas, such as attics,
garages, and crawlspaces, should be insulated. Foam or fiberglass
insulation can be purchased at most hardware stores.
Insulation should cover the entirety of a pipe.
- Plastic is more tolerant of cold expansion than copper or
steel. Houses in colder climates might benefit from the exclusive
use of approved plastic plumbing.
- Water supply for exterior pipes should be shut off from
inside the house and then drained.
- Sprinkler systems are particularly vulnerable to cracking due
to cold-weather expansion. In addition to turning them, it helps
to purge the system of any remaining water with compressed
- Homeowners should be aware that much of the plumbing system
travels through areas that are significantly colder than the rest
of the house. Because it is impossible to monitor the temperature
of every portion of the plumbing system, indoor air temperature
should be kept high enough throughout the winter to keep pipes in
any unheated places from freezing.
Leaks in the Building Envelope
Leaky window frames, door frames, and electrical outlets can
allow warm air to escape into the outdoors.
- Windows that leak will allow cold air into the home. Feeling
for drafts with a hand or watching for horizontal smoke from an
incense stick are a few easy ways to inspect for leaks. They can
be repaired with tape or caulk.
- On a breezy day, a homeowner can walk through the house and
find far more leaks than they knew existed. Leaks are most likely
in areas where a seam exists between two or more building
- Because hot air rises into the attic, a disproportionately
larger amount of heat is lost there than in other parts of the
house. Like a winter hat that keeps a head warm, adequate attic
insulation will prevent warm indoor air from escaping. Attic
insulation should be 12 inches thick in cold climates.
- Storm doors and windows should be installed to insulate the
house and protect against bad weather.
The heating system is used most during the winter so
it’s a good idea to make sure that it works before
it’s desperately needed. The following inspection and
maintenance tips can be of some help to homeowners:
- Test the furnace by raising the temperature on the
thermostat. If it does not respond to the adjustment quickly it
might be broken.
- Replace the air filter if it’s dirty.
- If the furnace is equipped with an oil or propane tank, the
tank should be full.
- Use a hose to remove leaves and other debris from the outdoor
condensing unit, if the home is equipped with one. Protect the
unit with a breathable waterproof cover to prevent rusting and
freezing of its components.
- Remove and store window air conditioners when they are no
longer needed. Cold air can damage their components and enter the
house through openings between the air conditioner and the
- Ceiling fans can be reversed in order to warm air trapped
beneath the ceiling to recirculate. A fan has been reversed if it
Chimneys and Fireplaces
- The chimney should be inspected for nesting animals trying to
escape the cold. Squirrels and raccoons have been known to enter
chimneys for this reason.
- The damper should open and close with ease. Smoke should rise
up the chimney when the damper is open. If it doesn't, this
means that there is an obstruction in the chimney that must be
cleared before the fireplace can be used.
- A chimney-cleaning service professional should clean the
chimney if it has not been cleaned for several years.
- The damper should be closed when the fireplace is not in use.
An open damper might not be as obvious to the homeowner as an
open window, but it can allow a significant amount of warm air to
- Glass doors can be installed in fireplaces and wood stoves to
provide an extra layer of insulation.
- If debris is left in gutters, it can get wet and freeze,
permitting the formation of ice dams that prevent water from
draining. This added weight has the potential to cause damage to
gutters. Also, trapped water in the gutter can enter the house
and lead to the growth of mold. For these reasons, leaves, pine
needles, and all other debris must be cleared from gutters. This
can be done by hand or with a hose.
- Missing shingles should be replaced.
- Patio furniture should be covered.
- If there is a deck, it might need an extra coat of
Adequate winterization is especially crucial for homes that
are left unoccupied during the winter. This sometimes happens
when homeowners who own multiple properties leave one home vacant
for months at a time while they occupy their summer homes.
Foreclosed homes are sometimes left unoccupied, as well. The heat
may be shut off in vacant homes in order to save money. Such
homes must be winterized in order to prevent catastrophic
In addition to the information above, InterNACHI
advises the following measures to prepare an unoccupied home for
Winterize toilets by emptying them completely.
Antifreeze can be poured into toilets and other plumbing
Winterize faucets by opening them and leaving them
Water tanks and pumps need to be drained
Drain all water from indoor and outdoor
Unplug all non-essential electrical appliances,
especially the refrigerator. If no electrical appliances are
needed, electricity can be shut off at the main
In summary, home winterization is a collection of
preventative measures designed to protect homes against damage
caused by cold temperatures. These measures should be performed
in the fall, before it gets cold enough for damage to occur.
Indoor plumbing is probably the most critical area to consider
when preparing a home for winter, although other systems should
not be ignored.