Cavity wall extraction - is it worth it?

Brebal

I’ve had a company around to assess my CWI and been told that it’s wool and it’s all wet and sunk down. 

A quote for extracting it and putting it new stuff is £3k. 

I reckon it would take me at least 10 years to break even on energy bill savings, and that’s at the current rates. I’ll be living here definitely for the next five years, and after that not sure. 

I’ve lived in the property five years and seen no sign of damp so thought it would be ok. Then I was talking to someone who said they’d heard of a similar situation but damp started in the brickwork causing a wall to collapse and now I’m worried. 

I’m not eligible for any grants or anything. I’m getting another quote this week but from what I’ve read the first one is about right anyway. 

Anyone have knowledge or experience of this? 

stuart45

Did you get the company round after speaking to this person?
Although it can slump in time, it's not going to make your brickwork collapse.

Bendy_House

Brebal, is there any chance you could put that £3k towards external insulation? This would also 'waterproof' your walls,  so I'd imagine the existing CWI would then dry out over a bit of time, and could be topped up (somehow...) with additional stuff such as beads. You should then have 'double' insulation levels.

(Sounds sensible in my head).

Tbh, although I have heard of damp issues being caused by the wrong type of CWI in the wrong locations, this was mainly penetrating damp to the inside, and not walls actually collapsing. Mind you, could it cause ties to rot? I don't know.

My gut says, tho', if you need to spend £3k just to get back to a starting point, is there a better way to use the money to achieve a better effect? 

Is one wall in particular being affected? Eg against the prevailing weather? If so, then 'only' that wall would need ext insul. Other walls might be ok with a coating that would fully waterproof the outer skin, perhaps?

I mean, your outer skin is currently allowing water through - which is not unusual, hence the employment of cavities - but there 'should' be a way of preventing this. Surely?

Brebal

stuart45 said:

Did you get the company round after speaking to this person?
Although it can slump in time, it's not going to make your brickwork collapse.

No, the assessment was last week and I’ve just had this conversation with someone, not an expert. They were telling me anecdotal info - suggesting there could be damp I can’t see which would have bad consequences. 

I’ve got another assessment this week so can ask about it. 

stuart45

Normally dampness in the cavity would show.on the inner walls. Slumping can cause cold spots as well, which can get condensation there.
As Bendy suggested, it is possible that dampness can affect the wall ties, so possibly that's what the person was talking about.

Brebal

Bendy_House said:

Brebal, is there any chance you could put that £3k towards external insulation? This would also 'waterproof' your walls,  so I'd imagine the existing CWI would then dry out over a bit of time, and could be topped up (somehow...) with additional stuff such as beads. You should then have 'double' insulation levels.

(Sounds sensible in my head).

Tbh, although I have heard of damp issues being caused by the wrong type of CWI in the wrong locations, this was mainly penetrating damp to the inside, and not walls actually collapsing. Mind you, could it cause ties to rot? I don't know.

My gut says, tho', if you need to spend £3k just to get back to a starting point, is there a better way to use the money to achieve a better effect? 

Is one wall in particular being affected? Eg against the prevailing weather? If so, then 'only' that wall would need ext insul. Other walls might be ok with a coating that would fully waterproof the outer skin, perhaps?

I mean, your outer skin is currently allowing water through - which is not unusual, hence the employment of cavities - but there 'should' be a way of preventing this. Surely?

That’s an interesting idea. I’ll look into it. Thanks!

I’ll be armed with more questions now to ask this other company but there’s always the fact that they’re trying to sell me something…

I think I’ve got a moisture meter actually. Not sure if that will tell me anything helpful? 

As I say, no visible signs of damp. I’ve noticed a few slight cracks in the plaster appearing over time but nothing deep. 

Brebal

Oh and I contacted CIGA who say they have no record of my property so no guarantee for me. 

stuart45

A moisture meter isn't the best thing to use. A thermal imaging camera will show all the cold spots, or even a surface thermometer.

Bendy_House

Brebal said:

That’s an interesting idea. I’ll look into it. Thanks!

I’ll be armed with more questions now to ask this other company but there’s always the fact that they’re trying to sell me something…

I think I’ve got a moisture meter actually. Not sure if that will tell me anything helpful? 

As I say, no visible signs of damp. I’ve noticed a few slight cracks in the plaster appearing over time but nothing deep. 

I am not going to say that you should dismiss what this new CWI co is saying, but you do need to bear in mind why you are in this situation in the first place - because of a CWI company. So use what they say to build up a picture, but always require evidence for any significant claim.

How did they figure out that the CWI was wet and slumped? A test drill? If so, have you seen the result - what they presumably pulled out?

Brebal

Bendy_House said:

Brebal said:

That’s an interesting idea. I’ll look into it. Thanks!

I’ll be armed with more questions now to ask this other company but there’s always the fact that they’re trying to sell me something…

I think I’ve got a moisture meter actually. Not sure if that will tell me anything helpful? 

As I say, no visible signs of damp. I’ve noticed a few slight cracks in the plaster appearing over time but nothing deep. 

I am not going to say that you should dismiss what this new CWI co is saying, but you do need to bear in mind why you are in this situation in the first place - because of a CWI company. So use what they say to build up a picture, but always require evidence for any significant claim.

How did they figure out that the CWI was wet and slumped? A test drill? If so, have you seen the result - what they presumably pulled out?

They drilled holes all round. Didn’t show me anything, just told me the results and then sent a quote. It’s about £1600 for extraction and another thousand to put new stuff in. 

Bendy_House

Are the holes still there?!