I thought we were doing alright.
The front door gap is sorted.
The loft hatch isn’t a wind tunnel anymore.
Radiators are behaving themselves.
The blower door test has already had its little say.
And yet.
Most evenings it went the same way. Heating on, room more or less warm, ankles like they’re in a different house. You know that thing where your top half is fine and your feet are not. That.
At first I blamed the usual list. Windows. Old house. Weather. Me. But one morning I noticed the curtain move. Not “someone walked past” move. Just a small twitch. No one else there.
So I did what all serious retrofit professionals do.
I got some toilet paper.
Finding the invisible wind
There are proper tools for this. Smoke pens. Thermal cameras. The version I used was a strip of loo roll and a cold morning.
You hold it near places that really shouldn’t be windy.
Skirting boards.
Corners.
Where pipes come up through the floor.
Behind things you never normally look behind.
The bay window that always feels a bit off.
And you watch it flap about.
It turns out our living room is basically a reasonably polite room sitting on top of a suspended timber floor that is very keen to stay in touch with the outdoors.
The worst bits were easy to find once you started looking:
The skirting along the external wall.
The radiator pipe holes.
One corner where two boards meet and clearly stopped caring years ago.
None of this shows up in a way your brain can picture when you look at airtightness numbers. It just shows up as “why is this room still cold”.
The unhelpful part
I briefly went on the internet.
This was, predictably, a mistake.
Within a few minutes I was being told to lift the entire floor, install membranes, insulate between joists, rebuild half the house, and probably live somewhere else for a bit.
That is a future job.
This is not that job.
This is the “stop the obvious holes” job.
The £12 intervention
What I actually used:
One tube of flexible decorator’s caulk.
One can of expanding foam.
A very old knife for trimming the foam.
About an hour and a half of mild crawling about.
The rules were simple, mostly because I kept them simple.
If air can come through it, it gets sealed.
If it might move or crack, use flexible stuff.
If it’s a hole around a pipe, it gets foam.
So:
A thin bead of caulk along the skirting where it meets the floor.
Foam around the radiator pipes where they disappear into the void.
Caulk in the corner gaps between boards.
One particularly rude crack behind the sofa that I suspect has been there longer than we have.
Nothing structural. Nothing clever. Nothing you’d show anyone.
Just stopping the house from breathing through the floor.
The bit you actually notice
Two things changed that evening.
First, the curtain didn’t move.
Second, the room felt different. Not suddenly hot. Just more even. The thermostat still does what it always did, but the cold layer at floor level has mostly gone. You don’t get that odd effect where your head is comfortable and your feet are somewhere else entirely.
It also feels quieter, which I wasn’t expecting and still can’t properly explain.
This is one of those jobs that feels like it shouldn’t make much difference. Then you do it and you stop thinking about the problem altogether.
What I didn’t do
I didn’t:
Lift any floorboards.
Install underfloor insulation.
Try to fix the whole house in one go.
That is a bigger project and deserves its own mess, its own budget, and probably its own small wobble.
This was just about stopping the obvious draughts.
The boring but useful takeaway
If you live in an older house with suspended floors and you have cold ankles, do this before you do anything clever.
It’s cheap.
It’s quick.
It’s not impressive.
But it works.
And sometimes the difference between “still a bit cold” and “actually fine” is a gap you could lose a pound coin in that nobody has thought about for years.
Next on the list is probably the bathroom extractor fan, which I’m increasingly sure is more decorative than functional. But that can wait for another damp afternoon.
