Air leaks around an exterior door can significantly reduce interior comfort. If you have inefficient or a complete lack of weatherstripping, it can contribute to higher utility bills. To figure out how to insulate a door, you’ll need to do a preliminary examination. Damaged or missing weatherstripping might be the culprit. Additionally, gaps around the door frame might be letting cold air seep through. Your inspection will determine whether you need to address one or both of those issues.

How to Insulate a Door

Steps to replace or add weatherstripping to a door:

1. Remove old or damaged weatherstripping if present.
2. Thoroughly clean the surfaces where you intend to attach new weatherstripping.
3. The weatherstripping products that you select determines which tools you’ll need to cut the material. Use the hacksaw for metal products and a utility knife for vinyl or foam products.
4. Measure the door or door stop edges and cut appropriate lengths of weatherstripping.
5. Peel off the backing on foam weatherstripping to expose the adhesive side. Carefully press into place.
6. Cut other weatherstripping products and attach with nails or screws as specified in product directions.
7. If nothing is covering the gap between the bottom of the door and the threshold, install a door sweep.
8. To install a door sweep, mark the places where the screws go and drill the holes one size smaller than the screws.

Steps to seal a door frame:

1. Cut away any old caulk and scrub the surface clean.
2. Let dry completely.
3. Load tube of caulk into caulking gun and cut off tip.
4. Squeeze the gun trigger until caulk appears at tip.
5. Run tip along seam between door frame and house at a 45-degree angle.
6. Smooth the caulk to a uniform appearance with a wet finger.