Winterizing Your House, From the Attic to the Garden Hose

Winterizing a house mostly means keeping water away from cold air. Shut off and drain the outdoor faucets, insulate exposed pipes in the attic and garage, seal the drafts that blow onto plumbing, and keep the heat at 55°F or higher whenever the house is empty. Then get ready for snow before it falls.

The first fall in my house, winterizing meant two things. I called the sprinkler company to drain the system, and I made sure the air conditioners were covered. Over the years I've learned how much more there is to it. Most of it is small, and most of it is the kind of thing you only think about after something goes wrong.

Now it's the work we do for our clients every fall. This is the walk we take through a house, from the attic down to the garden hose. Do it yourself, or have us do it.

Plenty of houses in Summit, Chatham, Short Hills and Millburn have been added onto over the decades, and pipes end up in places nobody would choose today: a supply line crossing the attic to a third-floor bath, an outdoor faucet fed through an unheated porch. You can only protect the pipes you know about.

How do you protect pipes in the attic from freezing?

Attic pipes need two things. Foam insulation around them, and a spot on the warm side of the attic insulation. The second one matters more, and it's the one most people miss.

Where should a water pipe sit in the attic?

Pipe insulation slows heat loss. It doesn't make heat. A foam-wrapped pipe lying on top of the attic insulation is sitting in outdoor temperatures with a thin coat on, and in a long cold snap it can still freeze.

The safer place for an attic pipe is under the floor insulation, close to the ceiling of the heated room below, where the house's warmth reaches it.

So when you find a pipe up there, look at what's between it and the outside. If it runs above the insulation, along the underside of the roof, or behind a cold knee wall, write it down. When we find one, it goes in the client's photo report the same day. Moving the pipe or rebuilding the insulation around it is contractor work, which we arrange and oversee as a Steward Project. Better done this fall than after a ceiling stain in February.

How do you fit foam pipe sleeves properly?

Foam pipe sleeves only work if they fit snugly and cover the whole run.

• Buy the size printed for your pipe. Most household copper supply pipe is 1/2 inch or 3/4 inch. A sleeve that's too big leaves an air gap.
• Close the slit all the way and tape it, even if the sleeve has its own adhesive strip.
• Cut the ends at an angle so they meet tightly around elbows. A bare elbow loses heat faster than the covered pipe on either side of it.
• Cover valves and fittings too, leaving the valve handle where you can reach it.
• Keep foam away from heat sources: the metal flue pipe from a furnace or water heater, and recessed light housings unless they're marked as rated for contact with insulation.

Walk only on the joists or on floored areas. Between the joists there's nothing holding you up but the ceiling drywall below.

How do you find the drafts that freeze pipes?

Pipes usually freeze where cold air blows on them, not simply where a room feels cold. In most basements the worst spot is the top of the foundation wall, where the wooden frame of the house sits on the masonry. Pipes often run right along it.

To find drafts, wait for a windy day, wet the back of your hand, and move it slowly along:

• the top of the basement foundation walls, especially behind pipes
• the holes where pipes, cables and the dryer vent pass through an outside wall
• the door between the garage and the house
• the inside of a sink cabinet on an outside wall
• the bottom of each exterior door

A wet hand feels moving air long before you'd notice it any other way.

Small cracks take a bead of caulk. Bigger gaps around pipes take a can of expanding foam sealant made for gaps and cracks. Gaps around the furnace flue, the chimney or a gas line are a different job, so leave those alone and have them looked at.

While you're at the dryer vent hole, check the hood outside too. Our guide to cleaning a dryer vent explains why fall is the time to do it.

Worn weatherstripping and a missing door sweep are the usual culprits at doors. Replacing them is a small job, and one we handle on our regular home maintenance visits.

What about the attic hatch?

The attic hatch or pull-down stair is often one of the biggest air leaks in a house, because warm air rises straight through it all winter. Stick foam weatherstripping around the frame so the hatch closes against it, and lay a piece of rigid foam board on top of the hatch.

What should you do on the coldest nights?

The American Red Cross recommends a few habits for very cold weather:

• Keep the garage door closed if water pipes run through the garage.
• Open the cabinet doors under sinks on outside walls so room heat reaches the pipes. Move cleaning products out of reach of children first.
• Let the cold tap drip at a sink whose pipes run along an outside wall.
• Keep the thermostat at the same setting day and night instead of turning it down overnight.

We'd add one more. Close the fireplace damper when you're not using it, but only once the fire is completely out and the ashes are cold.

How do you winterize an outdoor faucet?

To winterize a standard outdoor faucet, take the hose off, close the shut-off valve inside the house, then open the faucet outside and leave it open all winter. The short pipe between the valve and the wall drains, and any water left behind has room to expand instead of splitting the pipe. It's one of the first things we do on a fall visit.

1. Disconnect the hose. Drain it, coil it and store it in the garage or shed. A hose left on traps water in the faucet.
2. Find the inside valve. It's usually on the basement ceiling or wall directly behind the outdoor faucet, sometimes a few feet away, on the pipe heading toward the outside wall.
3. Close it. A round handle turns clockwise. A lever handle turns until it sits across the pipe.
4. Open the outdoor faucet. Water should run for a few seconds and stop. If it keeps flowing, the inside valve isn't fully closed, or you closed the wrong one.
5. Drain what's left. Some inside valves have a small brass cap on the side, called a drain cap or bleeder. Hold a bucket underneath, unscrew it to let the trapped water out, then screw it back on.
6. Leave the outdoor faucet open until spring.
7. Tag the valve. A luggage tag that says "Outdoor faucet, closed for winter" saves someone in April from opening the wrong valve or forgetting this one.

How do you tell if you have a frost-free outdoor faucet?

A frost-free outdoor faucet (also called a frost-free sillcock) has a long body that reaches through the wall, so the actual valve sits inside the heated house. From outside it looks like any other faucet. From the basement you'll see a long metal tube passing through the wall, often about a foot long, with the supply pipe connected at its inner end and usually no separate shut-off valve.

Frost-free faucets still need the hose taken off. Watts' installation instructions for its frost-proof sillcock say the hose must come off so the faucet can drain. A hose left attached holds water in the long tube, it freezes, and the tube splits inside the wall.

Here's the catch. A split frost-free faucet usually doesn't leak when it freezes. It leaks the first time you open it in spring, and the water runs inside the wall or across the basement ceiling. So the first time each outdoor faucet is opened in spring, someone should stand in the basement behind it and watch. When we turn a client's outdoor water back on, that's exactly how we do it.

Older houses often have both kinds, frost-free on one wall and standard on another. Check each faucet on its own.

What can you do if an outdoor faucet can't be drained?

If an outdoor faucet can't be drained, take the hose off, fit an insulated cover over the faucet, seal around it, and keep the space behind the wall warm. We do exactly this on fall visits for faucets with no shut-off or a valve that won't turn.

• Fit an insulated faucet cover. Hard foam domes and padded bags both work if they sit tight against the siding. The cover holds in warmth coming through the wall from the house, so a gap at the edge lets the wind undo it.
• Seal the hole around the pipe. Caulk the gap where the faucet meets the siding, and seal the inside where the pipe passes through the wall. Cold air through that hole hits the pipe directly.
• Keep the room behind it warm. If the pipe runs through a closed-off basement storage room, prop that door open to the heated basement on the coldest nights.
• Don't force a stuck valve. An old valve that hasn't been turned in years can start leaking around the handle, or break, when forced. If it won't move by hand, leave it.
• Skip the towel. A towel or rag wrapped around a faucet soaks up rain and freezes solid. A proper cover costs very little and works far better.

A cover buys a faucet real protection, though not a guarantee in a long, hard freeze. The lasting fix is a working shut-off valve or a frost-free faucet. That's a short job for a licensed plumber, and one we arrange and oversee so it's done before next winter.

What about the lawn sprinkler system?

A lawn sprinkler system needs to be drained the way the installer specifies, which for most houses means a visit from the irrigation company before the first hard freeze. It was the first call I made that first fall. For our clients, we book it and we're there when they come.

How do you keep pipes in an unheated garage from freezing?

A sink in an unheated garage is one of the easiest places in a house for a pipe to freeze. Insulate the pipes, keep the garage door shut, and on the coldest nights keep the room above freezing with a small electric heater set low.

• Insulate both pipes under the sink. The Red Cross says hot and cold pipes in unheated spaces like garages should both be insulated. Use the same foam sleeves as in the attic.
• Remember the drain. The U-shaped trap under the sink holds water too. Insulation alone won't protect it in a long freeze.
• Close the big door, and look at the rubber seal along its bottom edge. If you can see daylight under it, the seal needs replacing.
• Shut it down for the season if you don't use the sink in winter. Close the sink's shut-off valves, open the tap to drain the line, and pour a cup of non-toxic RV antifreeze into the drain so the trap can't freeze.

Is an oil-filled heater safe for a garage?

In my own garage, which has a sink and no heat, I eventually added a small oil-filled electric heater for the coldest nights. I prefer oil-filled heaters for this. There's no open flame and no glowing coil, and they give off a slow, even warmth.

A heater in a garage still needs care:

• Buy one with a thermostat, a tip-over switch and overheat shut-off, and a safety mark from UL, ETL or CSA on the label.
• Plug it straight into a wall outlet. The Chicago Fire Department's space heater guidance says never to use an extension cord or power strip, and to keep the heater 3 feet from anything that can burn.
• Keep it well away from gasoline, the snow blower, paint and solvents. Gasoline vapor is heavier than air and spreads along the floor. Better still, store the gas can in a shed.
• Set it low. The room only needs to stay above freezing. Some models have a frost setting made for exactly this.
• Watch the outlet. Garage outlets are often GFCI outlets, the kind with test and reset buttons. If one trips overnight, the heater stops without telling you. A plug-in thermometer that sends an alert to your phone covers that.

The same fire department guidance says not to leave a space heater running unattended, and a garage heater is unattended by nature. So treat it as a stopgap for the coldest nights, checked every day, rather than a plan for the whole winter. If a garage needs heat all season, a permanent heat source is electrical work. We're not licensed for electrical, and we'd rather bring someone who is.

Crawl spaces and sink cabinets on outside walls need the same attention: foam sleeves on every pipe you can reach.

How do you get ready for snow before the first storm?

Get snow gear ready in the fall. Buy a shovel, service the snow blower and start it once, and stock an ice melt that's safe for pets if you have them. The first storm is the worst time to find out the snow blower won't start.

Where should you keep the snow shovel?

Buy a shovel before the first storm, not the morning of it. Keep one inside, by the door you use most, so you aren't digging your way into the garage to reach it.

What does a snow blower need before winter?

1. Fresh gas. Gas left in the tank since last winter goes stale and makes the engine hard to start. Drain it as the manual describes and refill. OPEI, the outdoor power equipment trade group, recommends gasoline with no more than 10% ethanol for this kind of equipment. Fill the tank outside, with the engine cold.
2. An oil change. The manual gives the right oil and the amount.
3. Air in the tires. Tires slowly lose air sitting in the garage all summer. The right pressure is printed on the tire or in the manual.
4. Spare shear pins. On a two-stage snow blower, these are small bolts designed to break if the auger hits something hard, so the gearbox doesn't. Keep a few spares and the wrench that fits them in a bag tied to the handle.
5. A test start, outside. Run it for a few minutes on the driveway. Never run it in a closed garage. The exhaust carries carbon monoxide.

Which ice melt is safe for pets?

If you have a dog, use a pet-friendly ice melt on your own steps and walk. The ASPCA recommends pet-friendly ice melts whenever possible, along with washing and drying your pet's feet after every walk, because chemicals on the paws get licked off. It also warns that ice melts can be dangerous if swallowed, so keep the bag closed and up off the floor.

Sidewalks around town may not be treated with pet-friendly products, so the paw wipe matters even when your own steps are covered. When we salt a client's steps, we use a pet-friendly product in any house with a pet.

Should you cover your outdoor air conditioner in winter?

Most outdoor air conditioners don't need a winter cover. Lennox says covering the unit isn't necessary and that covering the whole thing can trap moisture. If leaves are the worry, a short cover over the top does the job.

Covering the air conditioners was on my very first winter list. If you cover yours, clear the leaves out of the fins and around the base first, and use a breathable top cover rather than wrapping the whole unit.

One exception matters. If the outdoor unit is a heat pump that heats the house in winter, don't cover it at all. It needs air moving through it all season. If you aren't sure which you have, ask your HVAC company at the fall service.

Window air conditioners let cold air in all winter. Take them out if you can, or cover them inside and out.

What should you do before leaving the house for the winter?

Before leaving for Florida or a ski trip, leave the heat on at 55°F or higher, take care of the outdoor faucets, and arrange for someone to walk through the house regularly. A Wi-Fi thermostat that sends a low-temperature alert to your phone, and a few water leak sensors near the water heater and under sinks, tell you about a problem while it's still small.

A water heater more than five years old deserves a look before a long trip, too. Here's how often a water heater should be flushed and the signs it's overdue.

Ask before shutting off the main water for a long trip. On some houses, the heating system or a fire sprinkler system depends on that supply.

If you'd like someone to check the house while you're gone, that's what our home watch service, Steward Away, is for.

What does The Home Steward do on a fall winterizing visit?

On a fall visit, The Home Steward works through most of this list ourselves, in the same order, from the attic down to the garden hose:

• shut off, drain and tag every outdoor faucet, store the hoses, and fit insulated covers where a faucet can't be drained
• fit foam sleeves on exposed pipes we can reach in the attic, garage and basement
• replace worn weatherstripping and door sweeps, weatherstrip the attic hatch, and seal small gaps
• shut down and protect an unused garage sink for the season
• change the furnace filter and test the smoke alarms, carbon monoxide alarms and sump pump
• book the irrigation company and be there when they come

Anything that needs a licensed trade, like an attic pipe on the cold side of the insulation, goes in the same-day photo report. In spring we turn the outdoor water back on, watching the basement wall behind each faucet as we do.

On our Steward Estate maintenance plan, visits are timed to land inside the fall window. Steward Essential clients get the same work at their quarterly visit, which may not fall right as the weather turns.

When to call a professional

Most of this post is work we do ourselves. A few things need a license, and when they come up we find the right trade, get the quote, and are there when the work is done:

• adding a shut-off valve, or replacing an outdoor faucet that leaks, drips with the handle closed, or leaked inside the wall last spring
• moving an attic pipe that sits on the cold side of the insulation
• heat cable on a pipe, a permanent heat source in the garage, or an outlet or plug that gets hot while a heater runs
• a water stain on a ceiling below attic or bathroom plumbing

If you smell gas anywhere in the house, leave, then call the gas utility or 911 from outside.

Frequently asked questions

When should I winterize outdoor faucets in New Jersey?

Winterize outdoor faucets before the first night forecast below freezing. Late October or early November is a good time in northern New Jersey, while it's still pleasant to stand outside coiling a hose. Waiting for the first freeze warning means doing it in the cold, in a hurry.

Should an outdoor faucet be left open or closed in winter?

An outdoor faucet with an inside shut-off should be left open outside, with the inside valve closed. That lets the short pipe drain and gives any leftover water room to expand. A frost-free faucet with no inside valve stays closed, with the hose removed.

Can someone winterize my house for me?

Yes. Shutting off and draining outdoor faucets, fitting faucet covers, insulating exposed pipes and replacing weatherstripping is the fall work we do for homes in Summit, Chatham, Short Hills and Millburn. Anything that needs a licensed plumber or electrician, we arrange and oversee.

Can I leave an oil-filled heater on in the garage overnight?

Fire departments advise against leaving any space heater running unattended. If you use one to protect garage pipes on the coldest nights, choose one with a thermostat and automatic shut-offs, plug it straight into the wall, keep it 3 feet from anything that burns and well away from gasoline, and check it every day.

Should I cover my air conditioner in winter?

Most outdoor air conditioners don't need a cover. A breathable top cover keeps leaves out, while a full wrap can trap moisture inside. Never cover a heat pump that heats the house.

If you'd rather someone else walked the house with a flashlight every fall, that's what we do.

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The Home Steward is a home management service based in Summit, New Jersey, run by Sebastian and Kory, caring for homes in Summit, Chatham, Short Hills and Millburn.