Drafty Doors, Weatherstripping & Door Sweeps for Mountain Homes

Winter guide

Why doors leak so much air up here

In most homes, exterior doors are the leakiest openings in the house, and mountain winters make them worse. In the Kamas Valley, the Weber valley around Oakley and Coalville, and the open floor of the Heber Valley, wind crosses open fields and hits doors head-on. In Park City and the cabin areas, snow drifts against thresholds and melts into the gaps. And everywhere in Summit and Wasatch counties, the winter air gets very dry once the furnace runs. Wood doors and frames shrink, gaps open that weren't there in summer, and a door that latched fine in July rattles in January.

The good news is that most door drafts come from a short list of causes, and most of them are fixable in an afternoon.

Finding the drafts

Feel for it on a windy day. Run the back of your hand slowly around the edges of the closed door. Cold air is easy to feel when the wind is up.
Look for light. At night, with a light on outside, look around the door from the dark side for any glow leaking in. Any light means air.
The paper test. Close the door on a sheet of paper at several spots around the frame. If it slides out easily, the seal isn't touching there.
Watch for clues. Frost or ice on the inside of the door or the hardware, snow on the floor after a storm, and dirt lines on carpet near the threshold all point to leaks.
Check the latch. If you can push the closed door and feel it move, it isn't pulling tight against the weatherstripping, no matter how good the seal is.

The fixes, from simplest to biggest

1. Adjust the door before you replace anything

Many drafts are really alignment problems. A sagging door leaves a gap at the top of the latch side. Loose hinge screws let the door drop. A strike plate set too far out keeps the door from closing tight against the seal. Tightening hinges, swapping a short hinge screw for a long one that bites into the framing, and moving or adjusting the strike plate often closes the gap on its own. Always start here, because new weatherstripping on a door that doesn't close tight still leaks.

2. Replace worn weatherstripping

Weatherstripping flattens, cracks and tears over time, especially on doors that face the sun at elevation. The common types are:

Kerf-in foam or bulb seals. Most modern exterior doors have a slot, or kerf, in the frame that holds a replaceable seal. Pull the old one out and press in a new one of the same profile. This is the most effective and longest-lasting option.
Compression or bulb strips nailed or screwed to the stop on older frames without a kerf.
V-strip or tension seals for tight gaps on older wood doors.
Magnetic seals on many steel doors, which grab the door like a fridge seal.
Adhesive foam tape, which is cheap and quick but rarely lasts a full mountain winter on a busy door. Fine for a closet or a stopgap.

3. Fix the bottom of the door

The gap under the door is where wind and drifting snow get in. A door sweep mounted to the inside face, a door bottom that slides onto the base of the door, or an adjustable threshold can close it. Many exterior doors have a threshold with adjustment screws that raise it to meet the door bottom. The goal is light contact: tight enough to block air, but not so tight that the door drags or the seal wears out in a month.

4. Seal around the frame

Sometimes the draft isn't at the door at all, but behind the trim, where the frame meets the rough opening. Pulling the interior trim and filling that gap with low-expansion foam, then re-setting the trim, stops air that weatherstripping can't touch.

5. Know when a door needs more

A door that's warped, rotted at the bottom, split, or so out of square that seals can't touch it may need to be replaced. That's a bigger conversation, and we'll be straight with you about whether a repair will hold.

Doors that need special attention in mountain homes

Sliding patio doors

Sliders facing the view usually face the weather too. Worn rollers let the panel drop and open a gap at the top, and grit in the track freezes. Cleaning the track, adjusting or replacing the rollers, and replacing the pile weatherstripping on the panel edges makes a big difference. Our guide to sliding patio doors that stick, leak or ice up goes step by step.

Storm doors

A storm door adds a buffer of still air in front of the main door, which helps a lot in windy places like Coalville and Oakley. It only works if it closes fully, so replace weak closers and sweeps, and add a wind chain so a gust can't bend it back on its hinges.

The door from the garage into the house

This door is often the leakiest in the house and the one people overlook. The garage is cold, and the door often has only basic seals. Treat it like an exterior door. Building codes usually call for a solid or fire-rated door in this spot, so don't swap it for a lighter one.

Older homes and historic doors

Older farmhouses in Kamas and Oakley and the historic brick homes in Coalville have wood doors that have moved for decades. Weatherstripping on these has to be fitted to the door as it is now. We go gently on original doors and hardware.

Log and timber cabins

Log homes settle as the logs dry, and door frames are usually built with a settling space above them for that reason. If that space isn't sealed with a flexible material, it can leak a lot of air. Blocking it with something rigid can bind the door as the logs keep settling. Flexible backer rod and sealant, or trim that can slide, are the usual fixes.

Timing

October is ideal, before the first cold snaps. But draft work happens indoors, so it can be done any time during the winter, and a windy day is the best time to find every leak. If you're getting the house ready for winter, our fall home and cabin checklist covers the rest, and our snow-season prep and door and cabinet adjustments services cover the work. Local pages: snow-season prep in Kamas, snow-season prep in Coalville, snow-season prep in Oakley and snow-season prep in Park City.

Getting the house ready for winter visitors? See our holiday guest-ready home checklist, starting with the entry.

When to call a pro

Door or window company: replacing a warped, rotted or badly out-of-square door or frame, and new sliding door units
Garage door company: overhead door springs, cables, openers and track problems
Log home specialist: major settling problems or chinking repairs on log and timber cabins
Us: door adjustments, weatherstripping, sweeps, threshold seals, storm door closers, slider rollers and track cleanup, and sealing around frames and trim

Where we help

Call or text (435) 321-2591 Message us on Instagram

Drafty doors FAQ

How do I know if my door needs new weatherstripping?

Feel for cold air around the edges on a windy day, look for light around the closed door at night, or close the door on a sheet of paper. If the paper slides out easily or you see light, the seal isn't doing its job.

Should I replace the weatherstripping or adjust the door first?

Adjust first. Loose hinges and a misaligned strike plate keep a door from pressing against the seal, so new weatherstripping won't help until the door closes tight.

What's the best door sweep for drifting snow?

It depends on the door and threshold. A sweep or door bottom that lightly touches an adjustable threshold usually works best. Too tight and the door drags; too loose and snow blows under.

Why does my cabin door have a gap above it?

Log and timber homes settle as the logs dry, so door frames often have a settling space above them. It should be sealed with a flexible material so it blocks air without binding the door as the logs move.

Can you fix drafty doors at my house or cabin?

Yes. We adjust doors, replace weatherstripping, sweeps and threshold seals, fix storm doors and sliders, and seal around frames. Call or text (435) 321-2591, or message @kamasvalleyhandyman on Instagram, with your town and photos of the door.

We focus on general handyman work and are not a licensed electrical, plumbing or general contracting company. For jobs that need a licensed trade, we'll tell you upfront and point you in the right direction.

Drafty doors, weatherstripping & door sweeps