Insulation Beads to replace wool in North facing cavity wall

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Prosper

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I live in a terraced townhouse built 1988. New neighbour wants to replace the wool insulation in cavity front wall with beads. Says that price he's paying also covers doing my side. However, I don't want to have it done as I saw on AAM a previous thread from last year and so I'm not convinced it's worth doing.
My neighbour said that in the event that he has his side done and I don't, that the contractor said that he will put in a "brush" (I think that's what it's called") that will prevent the insulation wool on my side being removed and also prevent the beads coming over to my side.
I'm assuming that because they are terraced houses that therefore there is no divide/barrier between our two houses, and so I do not trust that if he gets his side done that my side will not be affected.
Any thoughts?
 
Yes a brush should be installed and you have noting to worry about if it's installed correctly

Inmo bead is far superior to wool insulation by the way.
 
Buddy1977 said:
you have noting to worry about if it's installed correctly
Click to expand...
Thanks for the reply Buddy - the problem is I'll have no way of knowing if it's installed correctly. I want to be a good neighbour but I really don't want my wall insulation compromised. The insulation in these houses is poor as it is especially in the north facing front wall as it is insulated with wool whereas the rear south facing wall of these houses are insulated with the white polyboard - why the original builder didn't use the white polyboard on the north facing front of the houses I don't know - must have been a good reason.
I'll look at the possibility of agreeing to having the beading pumped in to my side as well but I'm nervous about this due to what I read on previous thread on AAM (mould, condensation, beads coming out of every oriface etc..)
 
Prosper said:
I'm nervous about this due to what I read on previous thread on AAM (mould, condensation, beads coming out of every oriface etc..)
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Once there is adequate ventilation, you shouldn't have the mould and condensation. There is a glue that is pumped in with the beads, which means that they won't be pouring out of every hole.
As buddy said above, it would be better than the insulation that is there now.

Having said that, you need to verify that the company doing the work are "fit for purpose". Do some research on them. Also, as you are in a terraced house, what about the neighbour on the other side of you - how is the bead and wool insulation going to be managed at that junction?

Do you know the thickness of the white polyboard? From my understanding, that is the inferior to the wool insulation and thus it wasn't used in the north facing wall.
 
Saw an opening done on walls that had bead blown in some years ago and also some that had wool blown in. Was surprised to see that in all cases the bead had substantially sagged but the wool was fully covering just as if it had been newly done. All of the houses had been insulated aprox 10 years ago, 8 with bead and 7 with wool, 15 in all. Reason for opening the walls was because the houses had been left there, builder went under and they have been purchased.
 
Jazz01 said:
Also, as you are in a terraced house, what about the neighbour on the other side of you - how is the bead and wool insulation going to be managed at that junction?
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Neighbour on other side is the end house and is set back about 7 feet from my house (still joining but her house is less deep and wider).

Jazz01 said:
Do you know the thickness of the white polyboard?
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Apologies, I made an error in the post. The white polystyrene board is in the north facing front wall and is about 30mm thick (the wool is in the rear south facing wall). Thanks for asking about the thickness because that made me check the air vent and so I realized my error. When I put my hand in it appears that the white board doesn't touch either the inner block wall or the outer brick wall (bigger gap to the outer brick wall). I assume now that the polystyrene board cannot be removed prior to filling the cavity with beads and hence the beads will be pumped into the gap between the white polystyrene board and the outer brick wall.
 
Bead install needs a minimum gap of 40mm to pump correctly

In your case the cavity doesn't appear to be suitable as the polystyrene board is in the middle of the cavity

It should have been installed tight against inner leaf.

There is a good chance your neighbours is installed the same way.
 
Also the polystyrene board cannot be removed. There is an extraction system available for old loose fill fibre and old inferior beads but not for polystyrene sheets as far as I am aware.
 
Interesting about the board not being removed. What would happen if there was a serious fire in a house but roof and walls were standing afterwards? Insurance says the house can be repaired and it goes ahead but insulation board is left inside the cavity?
 
Buddy1977 said:
In your case the cavity doesn't appear to be suitable as the polystyrene board is in the middle of the cavity

It should have been installed tight against inner leaf.
Click to expand...

I've just looked into the air vent upstairs and while the polystyrene board is close to the inner block wall, it's only about 30mm from the outer brick wall. From what you say it would appear the wall is not suitable for the beads. I'll pass this on to my neighbour and see what he says

Buddy1977 said:
Bead install needs a minimum gap of 40mm to pump correctly
Click to expand...

I'm now thinking of leaving well enough alone. The front bedroom is very cold in Winter. I've taken certain measures years ago to try to reduce draughts i.e. wedging strips of cork under the skirting boards (before I did this you could feel the draught of cold air) and using expanding foam in the airvents to fill the gap between the polystyrene board and the inner block wall thereby preventing cold damp air getting into the cavity via the air vents. I should have replaced the original windows with double glazed ones but I'll do that soon.
If my neighbour wants to go ahead with the beading I'll just have to hope that his SEAI approved contractor installs the "Brush" correctly in order to prevent beads getting into my side of the wall.
 
Just in relation to the board not flush with the wall - the pressure of the beads being pumped in, should (in theory) push the white board back flush against the wall, where is was supposed to be.

If you are not going ahead with it, then the brush will keep the beads out from your side, but some may get in there regardless, but not a problem. Just once they don't pull / suck out your insulation. It'll be hard to say that this won't happen.

Remember, it's your decision, regardless of what the neighbour or the contractor says. Don't feel pressured in making a decision you are not comfortable with.

As an aside - in relation to the front bedroom of your home, you should also look at hanging heavy, insulated curtains during the winter over the windows - should help with keeping the temperature up.
 
I wouldn't be confident the board would be pushed back by pressure of the bead as the board is normally wedged into a wall tie, and pressure of bead would not be enough to push it back.

Bead manufacturers wouldn't offer a warranty for this type of install
 
Buddy1977 said:
I wouldn't be confident the board would be pushed back by pressure of the bead as the board is normally wedged into a wall tie, and pressure of bead would not be enough to push it back.
Click to expand...
I spoke to one of the SEAI 's technical team and told them that the gap between the outer brick wall and the polyboard was 30mm in the only place I could check it i.e. the air vents. They confirmed that a 40mm gap is the minimum acceptable and they do not support the case for beading in this case as it could be problematic. I'll inform my neighbour of this and if he still decides to go ahead, then I have a decision to make as to whether I agree to the "Brush" being inserted or objecting to the him going ahead with the job at all.
Thanks for your input lads.
 
I told my neighbour about the minimum 40mm rule and he questioned why. I told him that he should contact the SEAI about that and also printed off the link below and wrote a note on it saying that I assume that if the gap is less than 40mm the beads might not settle properly and leave gaps where moisture might travel across to the inner block wall. His response was that he has paid the contractor a deposit. A bit foolish given that he had not heard back from me. I've decided as a result, not to agree to the "brush" solution to prevent any beads across to my side.

http://www.askjeff.co.uk/cavity-wall-fill/
 
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