Warning: include(../Includes/Plumbing_Links_Concise.php) [function.include]: failed to open stream: No such file or directory in /home/content/24/8485924/html/plumbing/Pipe_Freeze_Protection.php on line 127
Warning: include() [function.include]: Failed opening '../Includes/Plumbing_Links_Concise.php' for inclusion (include_path='.:/usr/local/php5/lib/php') in /home/content/24/8485924/html/plumbing/Pipe_Freeze_Protection.php on line 127
WINTERIZE A BUILDING - home - CONTENTS: How to winterize or freezeproof a building - how to set the down thermostat or turn off heat entirely. How to avoid freezing water supply pipes and drain piping, drains, traps, toilets, etc.
How to winterize pipes: frost protection for plumbing systems. Use of heat tapes, heat sources, pipe routing, to prevent freezing pipes
POST a QUESTION or READ FAQs about how to protect buildings, piping, heating equipment, water softeners, wells, & foundations from freezing, ice, & frost damage
InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.
Building winterizing or freeze-proofing guide: this article series provides step by step details in winterizing a building or freeze protection for buildings where heat may be lowered or left turned off. Avoiding freezing pipes in buildings also means avoiding later leaks, water damage, or possibly mold contamination.
The articles at this website will answer most questions about freeze protection for piping and other building plumbing and heating system components: how to winterize a building to avoid frozen pipes, and how to thaw frozen water supply & drain piping, wells, & water tanks.
A Detailed Guide to Winterizing a Building to Protect from Frozen Pipes, Leaks, Water Damage
What happens when water freezes in a copper pipe?
Our separated copper pipe solder joint (above left) shows how freeze damage to a heating system baseboard pipe can cause the copper pipe to simply slip apart at the solder joint. Our freeze-bulged and split copper water pipe (above right) shows how a copper water pipe can freeze, expand, and burst.
The resultant building water flooding and damage can be extensive and in some cases may involve a costly mold remediation project as well. Also, failure of an owner to take appropriate steps to prevent freezing pipes and water damage can result in loss of insurance coverage in some instances. For example, turning off heat without also winterizing a home would be an improper practice likely to lead to frozen burst pipes and water damage and mold contamination.
Our photo at left shows a separated solder joint caused by freezing at a heating baseboard copper pipe. The repair of this leak is shown later in this article.
Our page top photo shows a frozen, burst water pipe close to an elbow. We suspect that the process of heating the pipe during soldering of the elbow connection might soften the copper in this location, permitting the very rounded expansion shape at the point of pipe rupture. The elbow itself may be more resistant to bursting during freezing.
Key Building Winterizing Topics to Avoid Freeze Damage
Freezing water pipes or drain pipes in a building are worse than inconvenient: often the frozen pipes burst, risking serious water damage and even toxic mold growth in a building when the frozen, burst pipe later thaws and leaks into the structure.
Our photo (left) shows what we found on arriving at an unoccupied home that was for sale in New York. Shortly after freezing conditions had lifted a water trail was visible running down the curb adjacent to the home. We thought perhaps there was a leak at that fire hydrant but that was not the problem. The water supply line beween the home and the curb had burst.
The most extreme water and mold damage to buildings where pipes burst occurs in unoccupied structures whose conditions are not being monitored, such as a house for sale, or a remote, weekend home.
Other freezing weather damage besides floods from frozen pipes can include cracked plaster in older homes or cracked and dislocated wood flooring.
For buildings facing these extra risks, we provide a range of suggestions for winterizing or freeze-proofing a building as well as for monitoring building conditions so that prompt action can be taken to deal with a burst pipe.
Here is our list of key topics to consider when working to winterize or freeze-proof a building, along with links to more detail on these subjects:
1. Prepare the building to be left unattended: regardless of whether heat is to be left on or off:
Turn off unneeded electrical components. Modern TV's and items that use plug-in wall chargers and voltage converters are always using electricity. Unplug sensitive electronic equipment to protect against power surges or lightning.
Protect against rodents and animal damage: close openings into soffits, attics, basements, crawl spaces; be sure all trash and garbage have been removed from the building. Raccoons used to play with the Christmas ornaments in our attic, and mice would come into the building to eat anything, even books and bars of soap.
How we keep mice our of our building:
It's almost impossible to keep mice out of a building if they want to come in for the winter (they do). Beyond calling for regular visits from a pest control expert, here is what we recommend>
Removing any open food, storing food in cans or closed heavy plastic containers, and closing obvious mouse entry points will help. Our attorney ignored these suggestions and was plagued with mice, tolerating them until the morning that bleary-eyed, hardly awake, she was pouring rice crispies into her cereal bowl. A mouse leapt out of the box right into her cereal!
We leave mothballs (naphtha) in areas and even in equipment that tends to be invaded by pests looking for a sheltered place to spend the winter. Mothballs keep mice out of the filing cabinets in our unheated garage. Just put the whole box of mothballs, opened, but not poured out, into the cabinet, closet, or vehicle.
Insurance coverage: review your building insurance policy with your agent to be sure the property is covered when it is unoccupied.
Windows and doors: make sure that all windows are closed. If the building has triple-track storm and screen windows, make sure that the storm windows are closed with the glass "down" - not just the screens down. Latch and lock these openings.
Other building button-up details: Make sure building exhaust fans are off. If the building has an exhaust fan that leaks or blows cold air in or leaks warm air out, cover the opening (remember to remove those covers before use to avoid a fire risk.) Stop mail and magazine or newspaper deliveries. Let a trusted neighbor know you'll be away and ask them to keep an eye on the property.
Building winterizing & monitoring services: decide if you want or need a professional to winterize your building and or to monitor it during the time that it will be shut down.in some locales companies offer a winterized building protection service that ranges from weekly or even daily visits to check on a property to emergency response to a no-heat call or water-entry call that can be made automatically by a home security system when those conditions occur. If power outages are common in the area, a battery-backup for alarms and sump pumps would be a smart addition to the building.
2. Decide if the building heat going to be left "on" or "off" : the answer determines the type and extent of freeze-proofing steps needed.
Winterizing Advice When Leaving a Building Unattended in Freezing Weather
Freeze Alarms: systems that warn of loss of heat or freezing conditions in a building can notify you or a building manager when something needs attention.
buildings with an existing security system can add freeze-alarms. If your building already has a security alarm system it's usually a small matter to add low-temperature, loss of heat, loss of electrical power, and water flood sensors to the system.
If your building does not already have a security system some simple devices can turn on a light to alert neighbors to a heat loss or building flood.
Freeze-damage risk points in buildings: where building piping, mechanical systems, or other components are likely to freeze. Identifying drafts and cold spots, sealing drafts, using insulation, or adding a little heat can prevent freezing.
Our photo shows an example of a problem spot: piping under sinks in un-insulated pipe chases, piping in attics, crawl spaces, walls, garages, under floors.
Different piping materials (copper, steel, plastic) and different grades of water piping material affect the freeze-resistance of the piping. Installation details such as piping slope, routing, and insulation are important factors in pipe freeze problems.
Frozen hot water heating baseboards & radiators: how to prevent this problem which leads to loss of heat and more extensive freeze and later water damage to buildings. Our photo just shows a frozen, burst hot water baseboard heating pipe.
If a building heating system shuts down due to an operating problem (loss of electricity, a problem with the heater itself, or simply due to running out of oil) the heating system failure is likely to lead to frozen pipes which, when the weather warms, can cause serious building flooding and water or mold damage.
A burst heating baseboard line such as the ones we show here and at the top of this page can occur at more than one point in the heating system piping.
PIPE FREEZE-UP POINTS, warns about burst building drains aswell as splits or separations in supply piping & heating system piping how to prevent freezing drain piping when water pipes area exposed to drafts or freezing temperatures.
Pipes run through a cold corner or subjected to drafts may freeze and burst even when some building areas are quite warm.
Watch out for
for leaks and slow drips into drain systems. Even though you think the building is warm enough, slow water trickling down a shallow drain line outside of the building can build up enough ice to block the drain or even freeze and burst the drain pipe.
That is because a dripping faucet or a toilet that runs can send a slow trickle of water down a drain line through the heated building into an outdoor shallow drain exposed to freezing conditions and leading to freezing or even a burst drain pipe. These breaks also occur in an un-heated crawl space, basement.
Outdoor drain lines may be above the frost line and may be depending on proper slope to avoid retaining water that then freezes.
But a slow trickle or drip of water can still freeze in those locations and it can also flood a septic drainfield or soak pit.
Heat tapes & other heat sources to avoid frozen pipes: safely to avoid freezing pipes but also avoid fires.
Using fans to move air, small point-source electric heaters or light bulbs, adding heat to crawl spaces, opening cabinet doors and similar steps can protect problem spots from freezing in a building when its temperatures are set low.
We discuss use of heating cables on plumbing supply and drain pipes at Heat Tape Guide.
Watch out: as we explain at Heat Tape Guide, some models of heat tapes used for freeze protection can cause a building fire if the tapes are not installed according to the manufacturer's recommendations, particularly if the tape crosses over itself.
As Ryan Duffy points out, connecting the heat tape to a GFCI-protected circuit can substantially reduce the risk of heat tape fires. However if the GFCI-protected heat tape circuit trips-off during typical current leakage conditions and without drawing attention of the building occupants, the risk of freeze damaged piping, leaks, water damage, and mold damage will be increased.
The US CPSC recommended in 1994 [PDF] that HUD consider dropping its no-GFCI-on-Heat-Tape-Circuit provision, and that heat tape powering electrical circuits be be protected with a GFCI device in the electrical panel rather than at the electrical receptacle or "outlet". Ground fault protection was first required in the 1987 NEC for heat tapes that did not have a metal covering. In 1996/1999 the NEC expanded the requirements for GFCI protection and specified that mobile homes would have at least one heat tape receptacle. [A significant number of heat tape-related fires occurred in mobile and manufactured homes.]
See FREEZE-PROOF A BUILDING where we describe GFCI protection on heat tape circuits powering heat tapes for manufactured and mobile homes. Similar issues regarding building water entry control are discussed
at Sump Pump Inspection.
Heating systems and their effect on building winterizing plans
Heating systems should be inspected and if necessary cleaned and tuned before leaving heat on in a building in order to assure that the heater is in reliable condition.
Heating boilers that are to be left turned on also need water supply left turned-on for both hydronic (hot water) and steam heat systems, but we outline a little plumbing trick will let you turn off all other water supply in a building.
Furnaces & electric heating systems do not need water to be left on in a building.
Hot water heat continuous circulation can be used in hydronic systems to reduce building freeze-ups. Steam heat system condensate returns need to be freeze-protected.
See WINTERIZE - HEAT ON PROCEDURE for a discussion of what to do to assure that your warm air furnace or hot water heating boiler or steam boiler will operate safely and reliably throughout the heating season.
WATER TURN OFF? where to turn off building water, what water to leave on, how to safely leave hot water heat on with other water shut off. Draining water tanks, water pumps, hot water tanks.
Winterizing steps to take in a building - (in this article) winterizing or freeze-protection for building water supply piping, turning off water, preventing freezing pipes, draining piping systems, shutting down a building entirely: draining piping, turning off heat and electricity.
Reader Question: how can I prevent a too-shallow water line from freezing outside
I have an outside pump and tank attached to 50' 3/4" hose (buried in ground about 12")which draws water from a buried tank. The tank is deep enough to not freeze but my poor design does not allow me to drain the tank or the 50' length of hose with a foot valve at the end of it. What can I put down the line to prevent freezing like last year which blew up my hose. - Tony 10/13/2012
Reply: 4 tips on how to freezeproof a buried water that is too shallow for normal frost protection
Tony, I can think of several suggestions in escalating levels of trouble and detail
Use compressed air: If the home is being shut down entirely you can try blowing all water out of the buried water line using compressed air; you'll have to make-shift some fittings to make it easy to send air through the buried water line from one end, leaving the other end open; even so this may not get all of the water out of the hose or water line but it may be enough.
I converted a used A/C refrigerant gas canister that I pressurize either using a home tire inflator or at a gas station - taking care not to exceed the pressure ratings of the can (which could kill you). HVAC suppliers sell a kit that will convert the used canister to accept a schrader valve type tire inflator fitting that makes the job easier.
A friend used this approach, forcing air back down a water supply line, to keep a water pick line from a lake from freezing in winter.
Use RV type food-grade antifreeze: use a food-grade antifreeze intended for RVs, forcing it into the buried water line. Do not use automotive antifreeze which will first make you blind, then may be fatal.
Excavate, insulate and install a suitable heating tape or wire along the pipe run. This approach requires that you trust elecrical power will remain on.
Excavate, insulate, and install a heating loop in an insulated piping trench. Where rocky soils prevent getting a water pipe below grade it can be difficult to solve a freeze-up problem. An engineering friend, Stu Tucker designed, and I helped install an expensive freeze-proofing system for an uphill septic effluent piping system.
Stuart's design included trenching around the existing buried piping, insulating the whole trench with solid foam insulation, and the installation of a small diameter fluid heater tubing loop that is connected to a tiny water heater.
We filled that system with an antifreeze mix, added a timer, temperature sensor, and pump to circulate the heated antifreeze mixture through the trench. The system worked, though it was so expensive you wouldn't want to hire someone to do the project. This approach requires that you trust elecrical power will remain on.
Excavate and bury the water line below the frost line. This may be the best approach in some areas, but in Northern Minnesota plumbers place outdoor lines six to eight feet below ground level for frost protection - it's not a trivial job.
Reader Question: can I add a recirculating pump to prevent heating zone pipes from freezing?
Have an Ultimate oil burner/boiler ( DHW coil removed), with 4 zones.
1st zone main floor,
2nd zone upstairs,
3rd zone sunroom addition,
4th zone Amtrol indirect HW maker
2nd heating zone piping freezes up with cold weather (usually below 20F).
Thermostat in master br must be kept at 59-60F otherwise other two bdr's get way too hot.(poorly designed loops for the pipes, too $$ to fix)
Is there a way to add a recirculating pump to keep a small flow of HW moving thru the 2nd zone even when the zone isn't "officially" calling for heat? Kinda like the idea where a pump is added to the furthest HW faucet in a home that keeps HW flowing so there's no need to run the water forever to finally have the HW reach the faucet.
Only other way to describe it would be for the 2nd zone valve to have variable flow-trickle to prevent pipe freeze and fully open when stat calls for heat. Crazy idea? Impossible solution?
Reply: adding a variable speed hot water heat circulator pump or an auxiliary circuilator pump or re-wiring for continuos water circulation
Yes there are several possible solutions:
Turn up the thermostat: immediately pending other steps, keep the temperature high enough to avoid freezing - in your case 60F
Set the circulator to run continuously: Assuming that your system runs with a single circulator and multiple zone valves, you can have your heating tech wire the circulator to run continuously.
This is how homes in Canada are usually heated; it's custom in the U.S. to have the thermostat call for heat by turning on the circulator and the boiler temperature turn on the boiler via the aquastat. But in Canada the circs run all during the heating season (at least on many systems) and the TT is wired to turn on the heating boiler.
You could install a variable speed circulator for the above application (see extra notes at 4. below)
See CIRCULATORS VARIABLE SPEED
You could install a booster or extra circulator just on the freeze-prone zone. In this arrangement you would think you'd want to latch open the zone valve manually so that the circ could push water around, but you may have to also change the zone valve wiring to NOT call for heat - otherwise when the zone valve is manually latched open, its internal end-switch will also turn on the main circulator.
In other words, you can convert the problem zone to one that is always circulating. If you install a variable speed circulator you can circulate water more slowly through that zone (or all zones) continuously. When the boiler temperature drops below the cut-in the boiler will cycle and provide heat.
Alternatively if you disconnected the trouble zone's zone valve end switch wires (that normally turn on the main circulator), then latch the zone open, then add an additional variable speed circulator just for that zone, you'll circulate water more slowly.
How to Empty the Water Tank or Pressure Tank - Building Freeze Damage Protection
Question: How do we get water out of inaccessible water heater & water pressure tanks?
Concern: We have a crawlspace containing a hot water tank and pressure tank.
The water supply is from our well.
We need to close-up for the winter and need to let the water out.
The crawlspace door is at other side of the cottage.
Kinda far to crawl back and forth over hilly ground.
The crawlspace vents are screened.
We almost bought a tube that is powered by a drill, to let the water out via hose, I believe it is called; a drill pump.
I asked a nearby plumber and he said, take it back, may not work next year, etc.
Also this plumber does the service for us, with a pump. Also a plumber will remove the sediment from the tank.
Our photo (above left) of a horizontal water pressure tank was provided courtesy of reader Doug Mehak.
We want to empty the hot water tank and pressure tank ourselves, have been doing so for over 35 years.
This crawlspace is new, this year.
My husband just emptied the other 02 house pipes, in case it got below zero this week, and water is everywhere.
Next week, we will go to the cottage one more time and then close for the winter, any suggestions as to
how we can empty the hot water tank and pressure tank, ourselves?
Cottage with crawlspace is in Haliburton, Ontario, Canada.
At least thanks for reading my concern, Ha Ha. - R.M., Ontario, Canada.
P.S. These are some solutions we are considering:
--empty water by opening kitchen and bathroom faucets above, then only a bucket full will remain in hot water tank.
take the bucket out with you and voila.
(my husband says must mean city piping because we have a well)
--just let the water go through dirt floor, in time will go through ground.
(we are talking a 40 gallon tank, it will be muddy for a long time)
--another hardware guy suggested, drain the water into a bucket or pail, creating a contained puddle, so to speak.
then sump pump that water out.
A competent onsite inspection by an expert usually finds additional clues that help accurately diagnose a problem, such as noting the location, position of the problem water tank, what tappings on the tank are actually present and just where they are located, e.g. where there are only top tappings on the tank it may be possible to pump it out via a TP valve opening.
That said, thanks for writing with your own suggestions; on first reading your question, I hesitated in a prescription because lacking a clear description of the tanks involved, it appears that it not be possible to remove water from a water heater tank nor a water pressure tank located in an inaccessible crawl area.
While I'm not surprised at the description as often we find tanks squeezed into such areas, the installation does not sound correct, nor does it afford a means to empty the vessel; the result is not just a risk of freeze damage, but also other servicing cannot really be accomplished.
Watch out: water pressure tanks or hot water tanks in an inaccessible location are not only hard or expensive to service, repair, or replace, they may be unsafe - because the lack of ability to inspect the tanks means that safety devices such as temperature/pressure relief valves could be leaking or clogged - resulting in risk of a dangerous explosion. And of course a tank could be leaking into a hard-to-access crawl area for a long time before anyone discovers the problem.
The view that "only a bucket full will remain in hot water tank" does not sound reliable to me; the output from a water heater is delivered by the pressure of incoming water to the tank; if the tank has no drain whatsoever and we simply run water in the building with incoming water shut off (say by an inlet valve or by turning off a well pump) water is delivered only until the pressure in the whole system drops down close to zero (actual pressure depends on location and elevation of components). But the tank will still be full of water.
Watch out: I do not advise dumping water into a crawl area - it's asking for mold and insect problems.
Draining water pressure tanks and hot water tanks using the tank drain
Usually both water pressure tanks and hot water tanks have a drain valve at the tank bottom.
When the water tank or hot water tank is located in a below-grade basement or crawl space or any other location where it is not convenient to drain the tank by gravity using a garden hose, we attach a pony pump to the tank drain and pump the water out of the tank and over to a suitable drainage location.
Details about types of pony pumps (or transfer pumps) including both self-contained pumps and the drill powered transfer pump you mention, are given
at PUMPS, PONY PUMPS.
Some bladderless water pressure tanks and some water tanks using an internal bladder can work in any position. Most water heater tanks are intended to work properly installed in an upright position, not jammed horizontally into a crawl space.
Watch out: if a water heater tank or water pressure tank that was designed to be installed in an upright position is installed horizontally the installation is improper, violates the manufacturer's installation instructions and warranty, may have a reduced life, will not work properly, and may be unsafe.
Emptying plumbing systems using compressed air
Some winterizing companies charged with emptying building tanks and pipes to prevent freeze damage open all pipes and drains to drain out what water they can (after shutting off incoming water of course), and then try blowing compressed air through the system.
While this helps move water out of pipes and might push some water out of water tanks or water heater tanks, I have not found this a completely reliable approach. Air can move through water pipes or tanks while leaving water behind, more so for piping that is not straight and pitched and still more so for tanks and vessels. Nevertheless, it's a useful step that reduces water in the system even it it can't completely eliminate it.
Emptying plumbing by cutting pipes
Professionals will also actually cut pipes if necessary to assure the piping system is drained fully, figuring that it's much less expensive to later repair the cut than to repair burst pipes in unexpected locations and to clean up and repair water damage to a building left unattended.
How to empty a water pressure tank or water heater tank using a pony pump or a drill pump
I agree that based just on the description provided, the most effective means of getting most of the water out of the tank in this circumstance would be to use an available tapping on the upper tank to insert a tube and use a pony pump or drill pump to pump water out of the tank, through a hose, to outdoors or to a nearby drain.
When circumstances demand tank replacement or when there is an opportunity for any other reason, I'd either relocate these tanks to an accessible area or provide easier access (in one such case we made an openable floor panel).
Our photo (left) shows our little pony pump at a job where we used it to empty a water heater tank through a garden hose to an outdoor location. Here I had not yet hooked up the pump but you can see the white pump body and the washing machine hose needed to hook it up to a tank drain.
See PUMPS, PONY PUMPS for details.
How to Empty Well Piping or Prevent Well Pipe Freeze-ups When Winterizing a Building
Reader Question: When draining water for winterizing, how do we get water out of the well, well piping, and submersible well pump?
When draining the water from a dwelling that is allowed to freeze, how does the water supply from the submersible pump, supplied with foot valve, drain so the at or above grade pipes don't freeze and break? - Nate, 10/12/11
Great question, Nate. There are two approaches to preventing water lines between the building and the upper part of piping inside the well from freezing
1. Well water supply outdoor pipes are buried below the frost line, including well piping from the point of exit of the well up to the building.
That's why at many older wells the well casing head was down in a "pit" - to protect it from freezing. Later the invention of the pitless adapter provided a fitting that permits the well piping to exit out of the side of the well casing below ground without leaking ground water into the casing at that point. That permits well casing tops to be brought up to above ground for improved sanitation.
2. On some wells that use both a submersible pump and a bladderless water pressure tank, a snifter valve allows air to enter the well piping from inside the building near the water pressure tank. To drain water out of the well piping inside the well a second drain fitting is installed in a tee in the well piping.
Search InspectAPedia for "Snifter Valve" and you'll find our details about this approach.
3. A third approach that is not commonly used but that I participated in installing was designed by IBM Engineer Stu Tucker for his home at Lake George NY. The home draws its drinking water right from the lake. Normally homes in that area pull the well piping out of the lake in winter to avoid freezing.
Stu designed a system that pumps air from the water pressure tank back out the incoming water line at sufficient pressure that he could be confident that the water in the well piping was pushed backwards out of the pick-up strainer and into the lake to a depth that placed air into the well piping even in the lake to a depth below the lake freeze-over point.
The system was not as complicated as one might think. It amounted to an overcharge of air in the pressure tank and use of a submersible pump that is in the lake (so there is no issue with loss of prime).
well with pitless adapter. I'm only concerned with the piping, inside the building, that is above frost level. I need to know if it will drain over a certain amount of time, or if I need to insert a tube and pump out the supply tubing to a level below frost line. Thanks - Nate
Nate if your well pipes are NOT below frost line (option 1) the answer is that you need to determine if you have a snifter valve and in-well drain or not (option 2). If you don't, you'll need to use approach like #3 below or your own suggestion.
How to Winterize a building to Prevent Freeze Damage
First we decide the level of building winterization to be undertaken. There are two very different approaches to protecting a building and its mechanical systems from freezing-damage:
Heat-on winterization: the first approach to winterizing a building involves keeping the building heated, but to a lower temperature. This approach is usually best for a building as it helps avoid indoor humidity, moisture, and even freeze-cracking of some building materials such as flooring or drywall. We discuss "Heat-On" building winterization steps
at WINTERIZE - HEAT ON PROCEDURE
Heat-off winterization: the second approach to winterizing a building is to turn off its heat, often also its electricity, drain piping, and take other steps to reduce the chances of freeze-damage.
This approach is taken when a building is to be left unoccupied for a long time, when the owners cannot pay for heat (though they may face later repairs that would have made the heating cost look attractive), or when a building has been abandoned, such as a foreclosed property. We discuss "Heat-Off" building winterization steps
at WINTERIZE - HEAT OFF PROCEDURE
Question: will an un-heated house develop a mold contamination problem?
Is it true that if a house is left unheated in the winter, it will grow moldy? - James 9/1/11
James, no, yes, well ... it depends.
Simply leaving a home unheated, starting by confining the discussion to temperatures, does not cause mold growth, in fact some mold growth is retarded by low temperatures.
But IF the home will also be at a high humidity for any reason (a leaky roof, plumbing leak, wet crawl or basement), when we turn off the heat we lose the added drying capacity that heating brings to the building. So the risk of mold contamination is greater than otherwise.
I've inspected plenty of homes left with no heat and found that they did not become a mold palace.
Wherever I've found an unheated home that had become a mold palace there were additional causes or conditions that led to wet or high humidity indoors, usually combined with the home being left unattended - no one watching for problems - which means that the mold palace could be horrible. The mold catastrophe shown in our photograph above occurred in a home that was left unattended for more than a month. The home suffered a burst pipe leak that wet the interior with hot water; the combination of wet conditions, heat left on, and very delayed discovery of the leak and mold problem led to extensive mold and water damage throughout the home.
The most severely mold contaminated buildings I've investigated have usually been cases in which there was a significant leak such as from a burst water pipe (with water supply and pressure left on) or burst hot water heating system piping that soaked building areas in a building that was left unattended for a long period (from 5 days to several months).
So in sum, you have to know something about the house and its leakiness and general inclination to moisture before you can answer the question for a specific home.
Question: How do we winterize a home that has not been used in months and with no central heat?
I'm not seeing how to approach a house that hasn't been used in months. The owner died. No central heat, and the water heater leaked months ago too. Well water. Very well insulated home. Air is in the lines of the house. Can I empty the pressure tank to the well, and run RV antifreeze and leave it at that? The house seems to go down to the lower 50's on average and has outstanding passive solar set-up. - Sean 12/15/11
When closing down a house with the Heat off method, will any frost damage occur to the drywall, etc. if So how would you prevent this? - Sean
When a home has already been unoccupied for some time and without heat as well, start by a complete inspection of the building for damage, including leaks, rodent infestation, etc. If the building is intact and undamaged, then proceed to winterizing it using the Heat-Off procedures we describe in this article series.
It is better for most buildings to be left with heat on, albeit at a low temperature to reduce the cost of that house "mothballing". Leaving heat "on" in a stored building means that the heating system must be safe and reliable, and still the building should be inspected frequently for leaks or damage. But if heat must be left off and the building is dry (without leaks) and winterized, it may survive reasonably well.
I agree that a building left with heat off in a freezing climate will be exposed to extreme temperature swings as well as humidity swings and that cracks and damage can occur as a result. Minor drywall cracks shouldn't be a significant repair problem, but leaks or even high humidity swings in a building can lead to serious damage to hardwood floors as well as risking a mold contamination problem.
Ask a Question or Search InspectApedia
Use the "Click to Show or Hide FAQs" link just above to see recently-posted questions, comments, replies, try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.
"New Electric Heat Tapes Help Prevent Fires," US Consumer Product Safety Commission (CPSC) #00936
Mark Cramer Inspection Services Mark Cramer, Tampa Florida, Mr. Cramer is a past president of ASHI, the American Society of Home Inspectors and is a Florida home inspector and home inspection educator. Mr. Cramer serves on the ASHI Home Inspection Standards. Contact Mark Cramer at: 727-595-4211 mark@BestTampaInspector.com
John Cranor is an ASHI member and a home inspector (The House Whisperer) is located in Glen Allen, VA 23060. He is also a contributor to InspectApedia.com in several technical areas such as plumbing and appliances (dryer vents). Contact Mr. Cranor at 804-747-7747 or by Email: email@example.com
"Freezeproof Your House," Mike McClintock, Rodale's New Shelter, p. 30, October 1985 (approximate date)
"How to Winterize Your Pipes," Mike McClintock, Homeowners How-To Magazine, p. 59-62, Nov-Dec 1979.
"HUD Regulation for Manufactured Homes; Requirement that Heat-Tape not include a GFCI [ copy on file as /plumbing/GFCI_Heat_Tapes_HUD_CPSC_Letter1994.pdf ] - ", Meeting Log, US CPSC, HUD, Dennis McCoskrie, ESEE, 2/14/1994
"Houses in Hibernation," Steve Bailey, New York Times, 24 October 2008 p. D2.
Thanks to reader Ryan T. Duffy for discussing the suggestion for GFCI's on heat tape circuits to reduce fire risk, October 2010.
Thanks to reader David Gould, BC, Canada, for pony pump requirements discussion, 1/27/2010
 Colorado Climate Center, "How deep is the frostline in the winter in various parts of Colorado?", website http://ccc.atmos.colostate.edu/questions.php, retrieved 3/1/13
 Cyber Regs, " ICC Subscriptions
International Residential Code for One- and Two-Family Dwellings". R403.3 Frost-protected shallow foundations, citing 2012 IRC, http://publicecodes.cyberregs.com/ icod/irc/2012/icod_irc_2012_4_par033.htm retrieved 3/1/2013
Home Inspection Education Home Study Courses - ASHI@Home Training 10-course program. Special Offer: Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on these courses: Enter INSPECTAHITP in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.
The Home Reference Book, a reference & inspection report product for building owners & inspectors. Special Offer: For a 10% discount on any number of copies of the Home Reference Book purchased as a single order. Enter INSPECTAHRB in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.
The Home Reference eBook, an electronic version for PCs, the iPad, iPhone, & Android smart phones. Special Offer: For a 5% discount on any number of copies of the Home Reference eBook purchased as a single order. Enter inspectaehrb in the order payment page "Promo/Redemption" space.
The Illustrated Home illustrates construction details and building components, a reference for owners & inspectors. Special Offer: For a 5% discount on any number of copies of the Illustrated Home purchased as a single order Enter INSPECTAILL in the order payment page "Promo/Redemption" space.
The Horizon Software System manages business operations,scheduling, & inspection report writing using Carson Dunlop's knowledge base & color images. The Horizon system runs on always-available cloud-based software for office computers, laptops, tablets, iPad, Android, & other smartphones
Wikipedia provided background information about some topics discussed at this website provided this citation is also found in the same article along with a " retrieved on" date. NOTE: because Wikipedia entries are fluid and can be amended in real time, we cite the retrieval date of Wikipedia citations and we do not assert that the information found there is necessarily authoritative.
Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
The Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 25th Ed., 2012, is a bound volume of more than 450 illustrated pages that assist home inspectors and home owners in the inspection and detection of problems on buildings. The text is intended as a reference guide to help building owners operate and maintain their home effectively. Field inspection worksheets are included at the back of the volume. Special Offer: For a 10% discount on any number of copies of the Home Reference Book purchased as a single order. Enter INSPECTAHRB in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.
Or choose the The Home Reference eBook for PCs, Macs, Kindle, iPad, iPhone, or Android Smart Phones. Special Offer: For a 5% discount on any number of copies of the Home Reference eBook purchased as a single order. Enter INSPECTAEHRB in the order payment page "Promo/Redemption" space.