The goal of window weatherstripping is to seal air leaks between the sashes, jambs and stops of the windows.
Ideally, weatherstripping should be part of larger sealing project, involving other air leaks, especially those that may not be noticed: holes and pathways in the plumbing, wiring and HVAC system and – if you live in a single-family wood-frame home – attic and basement leaks. If there is other air leaks in the home’s shell, sealing the windows may not help much for energy savings.
Caulking vs. Window and Door Weatherstripping
Caulking involves caulks and foams, and the rough opening of the window/door;
Window and door weatherstripping involves plastic, rubber, felt and metal materials installed on sashes, jambs, stops...
Though typically simple, window weatherstripping varies with the type of window and involves very different materials.
Weatherstrips come in several sizes, shapes and materials: metal, vinyl, plastic, rubber, felt, foam (or a combination of some these materials).
Installing double-hung, casement or sliding window weatherstripping involves different materials and techniques.
For a durable and effective weatherstripping of your wood double-hung windows, prefer V-strip materials.
Most professionals apply vinyl V-strip to side jambs and bronze V-strip on top sashes.
Sliding windows weatherstripping is tricky, but some new materials can make it easier.
Casement (and awning and hopper) windows are relatively easy to weatherstrip.