A well-hung door still lets in draughts, damp and heat loss if it isn't sealed against the weather. Weatherproofing closes the gaps around the door and protects the surface, so your home stays warmer, drier and cheaper to heat. Here's how to weatherproof a door step by step — and how to keep an external timber door protected once it's done.
What you'll need to weatherproof a door
| What you'll need | What it does |
|---|---|
| Weatherstripping (foam tape, V-strip or rubber) | Seals the gaps around the door edges |
| Door sweep | Closes the gap along the floor |
| Caulk and caulking gun | Seals where the frame meets the wall |
| Draught excluder | Stops draughts at the base of the door |
| Utility knife, tape measure, screwdriver | For measuring, cutting and fitting |
| Impranol Oil and a lint-free cloth | Protects an external timber door surface |
How to weatherproof a door, step by step
- Inspect the door and frame. Check the edges, frame and threshold for gaps, cracks, and any worn or perished caulk or weatherstripping.
- Fit weatherstripping. Pick the right type for your door, measure the sides and top of the frame, cut to length, and press it firmly into place for a snug seal.
- Add a door sweep. Measure the door width, trim the sweep to fit, and screw it to the bottom edge to close the gap along the floor.
- Seal gaps with caulk. Run a bead of caulk along any gaps where the frame meets the wall, smooth it off, and leave it to cure fully.
- Add a draught excluder. Fit one at the base of the door to catch any remaining draughts.
- Oil an external door. If it's an external timber door, seal the surface against the weather with Impranol Oil, applied evenly and left to dry between coats.
Keeping your doors weatherproof
Weatherproofing needs the odd check to keep working. Seals and sweeps wear over time, so look them over now and then and replace anything perished — and top up the oil on an external timber door once a year.
| Task | How often |
|---|---|
| Check weatherstripping, sweep and caulk | Every few months |
| Clean the seals so they keep their grip | As needed |
| Replace worn or perished seals | As needed |
| Re-oil an external timber door | Yearly |
Frequently asked questions
How do I stop draughts coming around a door?
Seal the edges with weatherstripping, fit a door sweep or draught excluder at the base, and caulk any gaps where the frame meets the wall.
What's the best way to weatherproof an external door?
Combine sealing the gaps (weatherstripping, sweep, caulk) with protecting the timber — an external wood door should also be oiled and, ideally, sheltered by a porch or canopy.
Do new doors need weatherproofing?
Often, yes. Even a well-hung new door can leave small gaps, and an unfinished external timber door must be sealed and oiled before it faces the weather.
How do I seal the gap under a door?
A door sweep fixed to the bottom edge, or a draught excluder at the base, closes the gap along the floor.
Will weatherproofing save energy?
Yes — sealing draughts cuts heat loss, so your home stays warmer and cheaper to heat.
A warmer, drier home
A few hours sealing gaps and protecting the timber makes a real difference to comfort and heating bills. If a door is past saving, it may be time to replace it — browse our oak external doors and hardwood external doors, built for British weather and ready to finish. Need a hand choosing? Our team is happy to help.
Related reads
| How to Treat External Wood Doors | Oil and protect exterior timber |
| Maintaining Your Internal & External Doors | Keep every door in good order |
| How Energy Efficient Are Your Doors? | Cut heat loss through your doors |
