How Much Weatherstripping Do I Need for Doors and Windows?
Part of the project planner: Getting the house ready for winter.
Weatherstripping seals the gaps around doors and windows, where much of the cold air gets in. Two doors and ten windows take about 223 ft with 10% extra, which is 14 rolls of 17 ft, plus 2 door sweeps. The weatherstripping calculator works it out for your house.
Feet for a whole house
Double hung windows of 36 × 48 in and doors of 36 × 80 in, with 10% extra:
| House | Weatherstripping | Rolls of 17 ft | Door sweeps |
|---|---|---|---|
| 1 doors, 4 windows | 93 ft | 6 | 1 |
| 2 doors, 6 windows | 148 ft | 9 | 2 |
| 2 doors, 10 windows | 223 ft | 14 | 2 |
| 3 doors, 14 windows | 316 ft | 19 | 3 |
| 3 doors, 20 windows | 428 ft | 26 | 3 |
| 4 doors, 25 windows | 539 ft | 32 | 4 |
Feet for one door
| Door | Weatherstripping (top and sides) |
|---|---|
| Standard door (36 × 80 in) | 16.3 ft |
| Narrow door (32 × 80 in) | 16.0 ft |
| Double door (72 × 80 in) | 19.3 ft |
Feet for one window
| Window | Double hung | Casement or single sash |
|---|---|---|
| 24 × 36 in | 12.0 ft | 10.0 ft |
| 36 × 48 in | 17.0 ft | 14.0 ft |
| 36 × 60 in | 19.0 ft | 16.0 ft |
| 48 × 60 in | 22.0 ft | 18.0 ft |
Choosing the type
- Foam tape. The cheapest, and fine for gaps of a uniform size. It wears out in two to five years.
- V-strip (tension seal). A folded strip of plastic or metal that springs against the door. It lasts longer and suits the sides of double hung windows.
- Rubber or silicone bulb. A tube that squeezes shut. It lasts a long time and suits doors.
- Door sweep. A strip that closes the gap under the door. A threshold with a seal is better for a door that gets heavy use.
- Rope caulk. A temporary seal for windows you will not open in winter.
Fitting it
- Clean the surface and let it dry, since foam will not stick to dust or damp.
- Measure the gap before you buy, so that the seal is thick enough to close it, but not so thick that the door will not shut.
- Cut each piece a little long, and press it into place without stretching it.
- Keep it out of the hinges, the latches and the drain holes.
- Check by closing the door on a strip of paper: if it slides out easily, the seal is too loose.
Insulation in the roof matters too: see the attic insulation calculator, and the ice melt calculator for the driveway. These are estimates: measure your own doors and windows.
Frequently asked questions
How much weatherstripping do I need for a door?
About 16.3 feet for a 36 by 80 inch door (the top and both sides), plus a sweep for the bottom.
How much weatherstripping do I need for a window?
About 17.0 feet for a 36 by 48 inch double hung window, and 14.0 feet for a casement.
How many rolls do I need for a whole house?
For two doors and ten double hung windows, 223 ft, or 14 rolls of 17 ft.
Which weatherstripping lasts longest?
V-strip and rubber or silicone bulb seals last longer than foam tape. Foam is cheap and easy to fit, but wears out in a few years.
Where do I find the drafts?
On a windy day, hold a stick of incense or a candle near the edges of the doors and windows, and watch the smoke or the flame move.
More guides
Tools & materials for this project
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Estimates only. Quantities depend on your materials, site and supplier. Confirm important numbers before you order, and follow local building codes for anything structural.