Cold bridge

Jamiehill · 24 Jan 2021

Hello,

I have recently converted my garage to an office. It's been built with cavity wall and 100mm insulation. I didn't hire an architect as wanted to save money.

The house was extended before we bought it and it had a 1st floor extension above the garage, this included having a steel beam half way into the garage to take the load of the extension, this beam had a 3 brick thick column built into the cavity wall to support it. I have continued the cavity wall along the outside wall, insulated, plastered etc and now realise that the column is a cold bridge.

I presume I really have to remove the plaster and put a section of insulation along the entire wall and then replaster.

If I don't I am guessing it will get wet and mouldy?

The good news is that I get to practise plastering again...

Thanks,
Jamie

HERTS P&D · 24 Jan 2021

Is it wet and mouldy now?

Also, did you double board the beam?

Andy

Jamiehill · 24 Jan 2021

HERTS P&D said:
Is it wet and mouldy now?

Also, did you double board the beam?

Andy

Hi Andy,

Thanks for your reply.

The beam isn't the issue as such, it is in the ceiling which was already bordeded when we bought the house. I have looked in the ceiling cavity and the plasterboard isn't touching the plasterboard at all. The issue I have is there is a brick column that supports the beam has been built into the cavity wall so there is now no cavity across a floor to ceiling height segment that's about 330mm wide. This only occurred to me after I bordered and plastered the wall as that section dried slower. My concern is that it will now cause condensation and mould and I am wondering if I need to rip out the plaster and install a layer of insulation now, risk it and see if it causes issues or if I need to totally redesign the wall.

And to confirm, there is no mould and the plaster is nearly completely dry, it was skimmed 4 days ago and is very cold so this isn't necessarily unusual on its own.

Jamie

Jamiehill · 26 Jan 2021

I'm going to try and paint it and see how it goes. As there has been no visible condensation so far and it's been rather chilly I think we might be okay. It's just a lesson learned

TimboTwo · 2 Feb 2021

It would be very unusual for a column to bridge the cavity. The inner skin is the load bearer.

Jamiehill · 2 Feb 2021

TimboTwo said:
It would be very unusual for a column to bridge the cavity. The inner skin is the load bearer.

Thanks for the response, it definitely bridges the cavity.

Mr Chibs · 2 Feb 2021

FWIW... I've got a solid column 450mm sq, in my house, and insulation on both walls, either side... yes, probably taking a hit on efficiency, but it looks good, as it's just brick, and there is no mould/condensation, so I wouldn't worry.

Jamiehill · 2 Feb 2021

Mr Chibs said:
FWIW... I've got a solid column 450mm sq, in my house, and insulation on both walls, either side... yes, probably taking a hit on efficiency, but it looks good, as it's just brick, and there is no mould/condensation, so I wouldn't worry.

Thanks, Mr Chibs