As mentioned, weather stripping fits between your door and the doorframe or
Start at the top corner of the door opening and place your first piece of weatherstripping so it is flush against the door frame. Peel off the adhesive backing about a foot at a time and press it into place as you go. Line up each piece so that there are no gaps.
Weatherstrips are generally manufactured from rubber and/or foam, but can also be purchased in silicone, felt and vinyl. Install a weatherstrip along the bottom or even around the whole door frame to minimise heat loss, and draughts and even in some circumstances prevent water ingress.
Caulking exterior doors is essential.
Caulking and insulating an exterior door helps to protect your property against the weather elements .
V-Strip - If you have a door that is in good condition and has a tight fit, a V-strip may be the best option for you. This type of weatherstripping is also a good choice if you're looking for a weatherstripping option that is durable and long-lasting.
Tighten screws or bolts on the door frame and strike plate
The screws or bolts that secure the strike plate should be checked periodically to make sure they are tight. If they are loose, the strike plate will not be able to properly receive the bolt, and the door will not close securely.
These are the main types of weather stripping to keep in mind: Plain or reinforced felt weatherstrip. Metal weatherstripping. V-Strips (tension seal or tension strips)
The weatherstripping should be slightly compressed against the door sides and top, and the bottom sweep should complete an airtight seal. Close isn't good enough here either.
The bottom of siding boards should not be caulked
Water is meant to exit through the bottom of each board. While paint does tend to somewhat glue these pieces together, caulking them is never advised and can cause permanent damage. Also, avoid caulking tongue-and-groove siding boards together.
Sealing outside frame
make sure there are no gaps around the outside edge of the frame. If there are any, it's relatively easy to fill them up with building foam (be careful not to overdo it, the foam expands and can apply pressure on the frame causing problems with door closing), silicone or sand and cement.
A glazing compound, which is similar to a caulk, is applied to the solid sticking side of the door. The glass is bedded into the opening and pushed into the compound to ensure there is a tight seal.
When left unsealed, the gaps between your door frame or trim and your home's siding can let in water, drafts and pests, so it's important to know how to seal a door frame properly. If you notice your old door sealant is cracked, degrading or damaged, then it's time to replace it.
If your drafts are around the sides or top of your door, I would recommend using some sort of foam tape. You can easily open your door, stick in some thicker foam tape, and let the door shut, and that will give you a much more snug fit that will prevent air from leaking in.
As mentioned, weather stripping fits between your door and the doorframe or threshold. The stripping can be made from a wide variety of different materials including rubber, felt, foam, vinyl or metal.