Possible water ingress & cold bridging - Who to call?

Rowley Birkin QC

Hi All,

Possibly posting in the wrong sub-forum, any advice welcome.

I bought a terraced house that had been renovated about 3 years ago. There's a new, flat roof, extension to the rear and the original home was dry lined and heavily insulated.

I've noticed small round spots at regular intervals appearing on internal walls in the extension to the rear and on the internal wall covering what used to be the chimney & fireplace.

The roof on the original structure is original to the best of my knowledge.

From my research so far, it sounds like these spots are the mushroom head fixings for the plasterboard slabs and that there's a cold bridge coming from outside.

These aren't wet to the touch but they are unsightly and I'm concerned about any potential water ingress.

At this point, I'm looking for advice as to who to call to investigate and give an estimate for fixing the issue.

Thanks for reading so far!

MOD NOTE: Moved from Plumbing and heating.

BryanF

Remove a section and inspect for dampness/mould & mildue.

This is the problem with dry-lining: The due point is often in the wrong place.

Calahonda52

Rowley Birkin QC wrote: »

Hi All,

...the original home was dry lined and heavily insulated.

I've noticed small round spots at regular intervals appearing on internal walls in the extension to the rear and on the internal wall covering what used to be the chimney & fireplace.

..
From my research so far, it sounds like these spots are the mushroom head fixings for the plasterboard slabs and that there's a cold bridge coming from outside.

These aren't wet to the touch but they are unsightly and I'm concerned about any potential water ingress.

At this point, I'm looking for advice as to who to call to investigate and give an estimate for fixing the issue.

Thanks for reading so far!

MOD NOTE: Moved from Plumbing and heating.

can you clarify that they are internal walls

Rowley Birkin QC

BryanF wrote: »

Remove a section and inspect for dampness/mould & mildue.

This is the problem with dry-lining: The due point is often in the wrong place.

That's the thing, I'm not keen on going at this myself but not sure what trade / profession to get in touch with.

Calahonda52 wrote: »

can you clarify that they are internal walls

Now that I think about it, on the extension the spots are appearing on what would be a new wall that butts up against the next door neighbor. To the best of my knowledge, it's not a party wall.

They're also showing up on what I assume is plasterboard that's covering the old fireplace.

The room is well ventilated.

listermint

Could this just be rotting mushroom fittings?

If its the shared wall cold bridging should not really be high on the occurrence scale.

Rowley Birkin QC

listermint wrote: »

Could this just be rotting mushroom fittings?

If its the shared wall cold bridging should not really be high on the occurrence scale.

Hadn't thought of that actually. That would still indicate some kind of water ingress though?

Rowley Birkin QC

This is now occurring in an upstairs room on a gable wall. Any advice on professional help (I honestly don't know which trade would deal with something like this??) appreciated.

MicktheMan

Rowley Birkin QC wrote: »

At this point, I'm looking for advice as to who to call to investigate and give an estimate for fixing the issue.

From my experience, the first step in solving your issue is to understand the cause of the problem. For this you need to have the house fully assessed which generally involves some internal air quality monitoring over a period (week to two weeks).
Bare in mind that there is rarely a single silver bullet solution to this type of issue and usually the long-term solution involves a number of items including some education of the occupants on moisture management in housing.

dathi

Rowley Birkin QC wrote: »

Hadn't thought of that actually. That would still indicate some kind of water ingress though?

you seem to misunderstand how a cold bridge works. the mushroom fitting allows heat to travel through it faster than the surrounding plasterboard making it cooler than the surrounding area. which allows moisture in the air in the room to condense on the head of mushroom fitting. it is not water traveling from the outside in through the mushroom fitting .

Lumen

Rowley Birkin QC wrote: »

That's the thing, I'm not keen on going at this myself but not sure what trade / profession to get in touch with.

In my unprofessional opinion you need a plasterer involved. Even if the solution isn't only plastering.

For reasons I'm not entirely sure about, Ireland seems to have fallen out of love with plastering in the last couple of decades, to the detriment of our housing stock.

Rowley Birkin QC

dathi wrote: »

Rowley Birkin QC wrote: »

Hadn't thought of that actually. That would still indicate some kind of water ingress though?

you seem to misunderstand how a cold bridge works. the mushroom fitting allows heat to travel through it faster than the surrounding plasterboard making it cooler than the surrounding area. which allows moisture in the air in the room to condense on the head of mushroom fitting. it is not water traveling from the outside in through the mushroom fitting .

Thanks for the clarification. That does make sense.

We have wall vents and vents in all windows that are always open. Also automatic velux roof windows that are set to ventilate the house 4 X times a day.

What else can I do to help minimise moisture in the house?

Rowley Birkin QC

Lumen wrote: »

Rowley Birkin QC wrote: »

That's the thing, I'm not keen on going at this myself but not sure what trade / profession to get in touch with.

In my unprofessional opinion you need a plasterer involved. Even if the solution isn't only plastering.

For reasons I'm not entirely sure about, Ireland seems to have fallen out of love with plastering in the last couple of decades, to the detriment of our housing stock.

Agreed. There's a very light skin in places.