Can anyone recommend anti-condensation paint?

DRP

In the winter (actually Nov - March), we have drips of condensation forming on the interior of our concrete front doorstep and the aluminium low profile threshold. This is almost continuous (rain or shine, so I am confident it is a condensation issue), and long-term has caused the floorboards to rot and the mat-well recess to be a pretty damp place.



I have taken a photo from the mat well at just below floorboard level. The horizontal strip t the top of the photo is the aluminium threshold (which you may be able to see is wet). The concrete of the doorstep is wet with drips coming down it. You can just see the bottom of an air brick to the outside - so there shouldn't be a ventilation problem . The various loose bricks are supporting the mat well hatch/door mat - a legacy of the previous owners and we will build a proper hatch once I have a solution to the condensation issue.

I have a plan:

1) Seal the step on the outside (although rainy weather doesn't really correlate with the dampness/'condensation' inside).

In an effort to reduce direct contact between cold materials and humid air in the house:

2) Paint the interior of the concrete doorstep with 'anti-condensation paint', above and below the floor level - is there a recommended product anyone has used successfully?

3) Fix a piece of timber ( quadrant or similar) to the interior of the concrete doorstep where it is exposed above floor level. ie. a thin piece between floorboards and threshold

4) Also is there such a thing as a non-metallic low profile threshold? ie. to prevent thermal bridging as described above.

Any thoughts would be appreciated - this is the last issue in a series of damp related problems that we are on the brink of solving! I don't want to put down a new floor when it will immediately come into contact with this wet area.

DRP

hi

Anyone used anti condensation paint?

Any recommendations?

There seems to be quite a variation in price (Amazon), so I was wondering whether there was a big difference in effectiveness!?

Gloomendoom

I'm not sure how a paint could stop condensation. To do so, it would need to have significant insulative properties. There are some paints available that absorb the condensation and release it slowly, but surely that will be of no benefit in your case as the damp will still be there.

ariba10

I can't get my head around Anti Condesation Paint.

Condesation is formed when warm moist air meets a cold surface and condenses back into water.

Either dry the air or warm the offending surface.

dampdaveski

DRP,
There is a new product that I use called Suretherm, this is a thermal anti condensation paint, it has lots of microscopically small glass beads in it which effectively trap air inside the paint, this gives it its 'thermal qualities.
I've used gallons of it over the last year and it has been very effective.
It's difficult to determine from that picture but it might work for you.
I use it on window reveals, external walls (on the inside), ceilings where it is difficult to fit insulation etc
Ones to avoid are the ceramic sachets you can buy, complete waste of time.
Google the name and you will find more info on it.

Another option you could consider is that where your floorboards meet the stone step, cut them back approx 20mm and fit a foam strip (something wider so it will compress into place), this will act as a bit of draught proofing and stop the thermal/cold bridge you have going on at the moment.

And not a recommendation for a chemical DPC anywhere

DRP

ariba10 wrote: »

I can't get my head around Anti Condesation Paint.

Condesation is formed when warm moist air meets a cold surface and condenses back into water.

Either dry the air or warm the offending surface.

In my situation I have cold bridging via thermally conductive materials, meaning the surface is below the dewpoint at the humidity levels of the air in my house.

The paint or any other insulating materials will block the cold surface from contact with the air (I hope).

Alter_ego

I've used anti condensation paint inside a yacht. It had small granules of cork in it - expensive and useless!

ariba10

You might find it in one of the big DIY stores, on the same shelf as the anti rain paint.

DRP

Well in the absence of any better ideas, insulating paint is the way to go. At fifty quid a 2.5 L tin, I'm open to some more ideas...

barnishroader

Would bituminous paint not suffice instead of expensive insulating paint??

I have used it on the back of mdf sill boards to prevent absorption of moisture and it works great.

It in conjunction with a strip of insulation to prevent cold bridging i would have thought would solve your problem.