How to cover spots caused by cold bridging from internal wall insulation fixings

fme

Hi all,

We had internal insulation fitted to this room about 10 years ago and noticed over last 3 years the cold bridging spots becoming more noticeable as per pic. (This was originally an attached garage built with hollow block)

PXL_20250106_131336982.PORTRAIT.jpg

I dont intend any major work but would like to know if there is a particular type of paint that would be best to at least mask the spots.?

There might be other options such as wallpaper or cladding but would prefer to simply paint over.

Thanks.

Hobby farmer

Zin BIN or Stain block maybe. It's expensive stuff but very good at stopping stains etc from showing through. Lining paper or as you suggest wallpaper might do the trick

Deregos.

https://www.boards.ie/discussion/comment/123025531#Comment_123025531

The spray can version is especially quick and easy to use.

10-10-20

Try the stain-block method first.

https://www.boards.ie/discussion/comment/105266927#Comment_105266927

The root-cause is apparently that the thermal caps were left off the top of the mushroom fixings, so they become a condensation point which then causes staining through oxidation.

Inviere

I got advice here years ago about the same problem, and it was to cover the spots with gloss paint before top coating with emulsion. Works very well.

whizbang

There was iirc a threqad a long time ago where the mushrooms seem to be wicking water back into the house..

The simple solution was to dig out the plaster on top of the fixing, block the hole with sealant, oil paint then refinish.

In your case if it has been 10 years then its not an issue. Believe it or not, the few spots I get simply wash off.. just seems to attract dust/dirt. Or just paint over; another 10 years is a no brainer.

GreeBo

https://www.boards.ie/discussion/comment/123027865#Comment_123027865

the spots will be slightly colder, so attract light condensation and hence get more dust etc sticking to them and appear dirty.

fme

Thanks all for the feedback - much appreciated!

heffo500

I put these caps on the mushrooms when I did them to prevent cold bridging.

https://www.goodwins.ie/products/thermal-bridging-insulation-cap-bag-100.html?filter_set%5B%5D=1413,1422

Too late for the OP but for anyone else, I think they're worthwhile.

DublinDilbert

https://www.boards.ie/discussion/comment/123033683#Comment_123033683

Did you drive the mushrooms below the surface so these sit flush? Did you bond these on?