Should I Caulk My Windows on the Outside?

LESLIE: Alright. Now we’ve got Jeff in Iowa on the line who’s doing some caulking, getting ready for the winter season. What can we do for you?

JEFF: Yes, I was wondering if I should caulk around the outside of my windows on my house. I have vinyl siding and I was told to caulk around the windows to seal the weather – the wind – out. But a carpenter friend has said that vinyl siding shrinks and expands so much, it wouldn’t be a good idea to caulk it.

TOM: Well, it depends. First of all, Jeff, how old is your house?

JEFF: It’s 1955.

TOM: OK. So, I don’t think it’s a bad idea to do that. If you use a very good-quality window and door caulk and you put it on with patience and accuracy around the window trim, I think it could do a good job of cutting down on drafts.

I will give you, though, another trick of the trade and that is to not only caulk outside but caulk inside. If you caulk between the wood window trim inside and the wall and the trim and the window, if it’s painted trim, you can use a white, acrylic latex caulk and you will be amazed how many drafts come around the body of the window and exit out around that trim.

So I think if you caulk both inside and outside, you can definitely reduce the amount of air infiltration that comes through the space.