If you've had your wall cavities filled with insulation ...

[brilllopad]

... what do the drill holes look like after it's finished? Are they very visible?

They are obvious at first. But blend in well when weathered.

Our walls are rendered, so the holes were just filled and painted and not at all visible

Couldn't tell you, I haven't noticed them!

It looks fine, you don’t even notice them. What you will notice is the damp and mould inside your house because the walls can no longer breathe.

Had ours done ~15 yrs ago. Brick facade house. Can't remember when I could last see the holes. They try to go in where the grout is, iirc, and match colours otherwise. Just looking at neighbour's house (mirror of our house, their walls done year after ours). Can't see their holes, either.... maybe some extra grout in a few places?

ps: we had issues with mould before the walls were done, much less since.

Damp and mould only happen if the wall insulation is done without thought or understanding of building science. Insulating walls is not a simple thing to do, but absolutely possible without causing mould and damp.

don't get it done I'm having lots of issues with damp and mould since having mine done on one of the free insulation schemes.
apparently insulation becomes damp within the cavity and cannot dry out so causes damp. I wish it was easy to remove ourselves.

My parents had their house done in the mid 80s. They drilled through the cement between the bricks then filled the holes with cement when they'd finished. You can't see where the holes were now!

Their house is warm and not at all damp (we never even opened the bathroom window after a shower and it was still never damp!). I suspect issues with damp may come from the house being a house that needs to breathe in the first place. Theirs was newer than that (built in the 60s I think) and was (and is) fine.

I had this in 4 houses - including parents
It's fantastic
Hole barely noticed- you have to look really hard.
Warmer in winter and as a bonus stops the house over heating in summer
Also NO mould at all
All houses need to breathe regardless so opening windows daily has always been recommended
I open certain windows for 20 mins daily.

In the end we cleaned it up ourselves as we have young children and the risk of fibre glass etc

Not visible. Had mine done in the spring. So far so good.

@Helpwalls I think you might find it useful to start your own new thread, you'll find more people able to help you. Best of luck, sounds awful!

I thought i had.

Thanks