Rubber and Foam: Where Each One Belongs
Last lesson we got the V-strip up on a door frame. Good. Now let's talk about the other stuff, because V-strip isn't the only weatherstripping out there and people get confused about what goes where.
There's basically four things you'll run into: V-strip, foam tape, rubber door sweeps, and tubular rubber gasket. Each one has a job. Use the wrong one and it either fails fast or doesn't seal right in the first place.
V-strip
We covered this one already. Vinyl or metal, folded like a V, goes on the door jamb where the door face meets the frame. Good for doors and double-hung windows where you've got two flat surfaces closing against each other. That's its whole world though. Don't try to use it on a bottom gap or a curved surface, it won't cooperate.
Foam tape
This is the stuff on a roll with adhesive backing, usually a strip of closed-cell foam. I use it on window sashes, mostly the top and sides where the sash meets the frame, and sometimes on a door where the gap is small and even.
Foam's fine for a low-traffic spot. It's cheap and easy to cut with scissors. But it's not durable if something's rubbing against it constantly. I wouldn't use it anywhere that gets a lot of contact and friction, like a door that swings open and shut fifty times a day. It'll crush and lose its bounce.
Foam also doesn't love big temperature swings. Fine for a window that mostly just sits there. Less fine for a spot that's baking in July sun and freezing in January. It'll get brittle over a few years. Not the end of the world, foam's cheap enough to just redo, but know what you're buying it for.
Rubber door sweeps
This is the bottom of the door, where V-strip and foam both fall short. A door sweep is a strip of rubber or vinyl attached to a metal or plastic bar that screws to the bottom of the door and drags lightly against the threshold or floor.
This is the single best dollar-for-dollar fix in this whole course, honestly. A ten-dollar door sweep does more for a drafty house than almost anything else you can buy. Cold air pools low, and the bottom of a door is usually the worst gap in the house. If you only fix one thing this fall, fix that one.
Installing one is simple. Cut it to width with a hacksaw if it's too long, hold it against the closed door so the rubber just brushes the threshold without dragging hard, mark your screw holes, drill pilot holes, screw it on. Test by closing the door. If it scrapes loud or makes the door hard to shut, loosen the screws and nudge it up a hair. You want contact, not a fight.
Tubular rubber gasket
Last one. This is a hollow rubber tube, sometimes with a flange that tacks or staples on. I use this on garage service doors and older sliding doors where the gap is bigger and irregular, more than V-strip or foam can handle. It compresses a lot more than foam does, so it forgives a door that's not perfectly square, which, let's be honest, a lot of them aren't.
A story on this, since I mentioned traffic
I brought sourdough to a ward party a while back and some kid slammed the screen door so hard the whole frame bent sideways, closer and all. I set my plate down, still in my church clothes, and reset the closer arm right there before I even thought about it. Bless him, he didn't slam it that hard on purpose, but that's what happens to weatherstripping and hardware on a high-traffic door. Whatever you put on a door that gets slammed by kids all summer needs to be rubber or the tubular gasket, something with some give. Foam would've been flat in a month.
Quick way to pick
If you're standing there staring at a rack of weatherstripping and not sure what to grab: flat surface closing on flat surface, V-strip. Low-traffic gap that just needs filling, foam. Bottom of any door, rubber sweep. Big or uneven gap, or a door that takes a beating, tubular rubber.
Before next time
Walk around your house and look at what's on your doors and windows right now. See if you can guess, before I tell you next lesson, which ones are the wrong material for the job. You'll probably find at least one.