Gapfil — Hand-Moldable Sealing Putty
The hole where the AC line goes through the wall is two inches of ragged plaster with a rag jammed in it. Press putty in with your thumb and that corner is closed — you walk past it and stop looking.
That is the gap it was made for.
Because you press it in by hand, the putty takes the shape of the hole instead of spanning it the way a bead of caulk does.
It grips every ragged edge on the way in.
It stays flexible instead of curing hard, so it moves with the wall instead of cracking away from it.
That is the whole difference between this and the tube in your drawer.
Your order is dispatched within 24–48 hours and typically arrives within 5–9 business days.
You'll get a tracking link the moment it ships, so you can follow it door to door.
Ordering from outside the US?
Allow 7–10 business days.
Every order is covered by our 60-day closed-gap promise, starting the day your order arrives.
Many issues are solved without sending anything back — damaged, wrong, or ill-fitting items are typically replaced free.
No extra taxes or shipping charges.
What you see is what you pay.
The rag comes out and the gap stays closed
There's a rag stuffed in the hole where the AC line goes through the wall, and it's been there long enough that you've stopped calling it temporary.
You tried caulk.
It laid a bead across two inches of ragged plaster and pulled away from the edges within a season, because a bead can only bridge a gap — it can't fill one.
That's the part that sits with you: the house isn't actually closed, and you've just been living with it.
You press it in with your thumb
It comes out of the pack like modelling clay.
Warm it between your fingers for a few seconds and it goes soft enough to push.
Then you press it into the hole with your thumb.
Because it's soft, it pushes into the ragged shape of the plaster — behind the pipe, up under the lip, into the corners a nozzle can't reach.
A tube bridges a gap. This one fills it.
Your hand is the tool, which is why it works on a hole shaped like nothing in particular.
Still sealed after the first hard rain
Caulk cures hard, and hard is the problem.
The wall moves in summer heat, the pipe shifts a few millimetres, and the hard bead lets go along one edge.
That's the thin dark line you found last time.
This stays flexible.
It moves with the wall instead of snapping away from it, so the seal holds through the hot week and the cold snap and the rain that follows.
You don't come back to it next spring.
That's the whole point of closing a gap properly — it leaves your head.
Our key statistics
Based on a survey of 500+ verified customers.
How it works
Three steps, one thumb, about ten minutes from the drawer to done.
Take out whatever's in there now — rag, steel wool, crumbled foam. Brush the loose plaster off the edges so the putty has something solid to grip.
Roll a piece between your fingers until it softens, then push it into the hole with your thumb. Keep adding until it's proud of the wall rather than level with it.
Smooth the surface flush with the plaster and you're done. No cure time to plan your evening around, no cartridge to throw away half-used.
What that one ragged hole has already cost you
You could spend each year:
- $100–150
- $10–20 a trip
- Two years
One pack of five sticks closes that hole, the one under the back door, and the three you'll find once you start looking. For less than half of the call you kept putting off.
Putty in your thumb vs. a bead from a tube
See why customers switch and stay.
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Others
The gap they'd been living with
Photos sent in by people who finally pulled the rag out.
Customer reviews
Questions, answered
will it actually hold on that?
— That's the shape it's built for.
You press it in with your thumb, so it takes the form of the hole — behind the pipe, under the lip, into the uneven edges — instead of laying a bead across the top the way a caulk gun does.
The wider and uglier the gap, the bigger the difference.
It stays flexible rather than curing hard.
A hard bead lets go along one edge the first time the wall or the pipe moves, which is the thin dark line you found last time.
Flexible putty moves with it instead.
It holds paint, so anywhere it's in a painted wall you can bring it back to the same colour.
Straight out of the pack it reads as a patch, so if it's somewhere visible — white trim, a door frame — smooth it flat first and paint it after.
Yes.
Outdoor gaps are where the flexibility matters most, because the temperature swing between a hot afternoon and a cold night is what breaks a hard seal.
Clean the loose material off first so it has solid edges to grip.
Each order is five sticks.
A narrow gap takes part of one; a two-inch ragged hole can take a whole stick or two, which is why the two-pack is the one most people choose.
If you're unsure, the free walkthrough tells you what to expect before you start.
That's the 60-day closed-gap promise.
Press it into the worst gap in your house and live with it for 60 days, through at least one heavy rain.
If it shrinks, cracks, or pulls away from the edges, you pay nothing.
60-day closed-gap promise
"Press it into the worst gap in your house and live with it for 60 days. If it shrinks, cracks, or pulls away from the edges, you pay nothing."
Press it into the worst gap in your house.
Not the easy one — the ugly one you've been avoiding.
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