Recommend Cavity Wall Bead Insulation

FiOT

Hi All,

Thanks to everyone who has been so helpful with all of my queries so far.

I would really appreciate if anyone could recommend, by PM, cavity bead insulation and installers that they have had experience of/know about.

It is for 200mm cavity in a new build.

Many thanks.

JonathonS

I suspect its going to be prohibitively expensive in a 200mm cavity but you should also check out BASF Walltite.

(I put up a similar post every time someone asks about beads. I have no connection with the company:))

BarneyMc

What part of the country are you based?

FiOT

BarneyMc wrote: »

What part of the country are you based?

Hi Barney,

I'm in Meath, just North of Ashbourne so I'm close to a few counties!

srf

I am of the opinion that the full fill cavity insulation is not the best option for a new build as there is a risk of moisture coming accross the cavity. I am also not at all convinced that the insulation will not settle in time and leave voids without insulation. The idea of a 200mm cavity will without a dougt increase the building cost as the foundation sizes need to be increased to support the wider wall. My opinion is that the better option is to use a 150 cavity and use a high density 100mm insulation. Plaster the inner face on the wall to give airtightness and this wall will then give a thermal mass to store heat.

BarneyMc

srf wrote: »

I am of the opinion that the full fill cavity insulation is not the best option for a new build as there is a risk of moisture coming accross the cavity. I am also not at all convinced that the insulation will not settle in time and leave voids without insulation. The idea of a 200mm cavity will without a dougt increase the building cost as the foundation sizes need to be increased to support the wider wall. My opinion is that the better option is to use a 150 cavity and use a high density 100mm insulation. Plaster the inner face on the wall to give airtightness and this wall will then give a thermal mass to store heat.

100mm insulation in a 150mm cavity WILL leave a 50mm void, all around the house, guaranteed. What U value will this give anyway?

srf

Hi Im back
If you use 110mm kingspan insulation in a 150mm cavity wall it will give you a U value for the wall of 0.15 and if you increase the insulation to 120mm it will give you a U value of 0.14
As far I can work out this is similar to what you will get with a pumped 200mm cavity. You will have made a saving of the use of special wall ties as the standard one will do in the 150 cavity. you will also save by not having to increase your foundation sizes.
I am convinced that the 150mm cavity is a better option with the rigid insulation as it also eliminates the risk of dampness.
ps I have no afiliations with any insulation company.

MicktheMan

srf wrote: »

Hi Im back
If you use 110mm kingspan insulation in a 150mm cavity wall it will give you a U value for the wall of 0.15 and if you increase the insulation to 120mm it will give you a U value of 0.14
As far I can work out this is similar to what you will get with a pumped 200mm cavity. You will have made a saving of the use of special wall ties as the standard one will do in the 150 cavity. you will also save by not having to increase your foundation sizes.
I am convinced that the 150mm cavity is a better option with the rigid insulation as it also eliminates the risk of dampness.
ps I have no afiliations with any insulation company.

In theory you may be correct, However, you are making a huge assumption here, which is, that the insulation boards will be installed properly.

Wegian

MicktheMan wrote: »

In theory you may be correct, However, you are making a huge assumption here, which is, that the insulation boards will be installed properly.

+1. This is why I am leaning towards the pumped bead option

srf

Just one note of caution is that you cannot be certain that the cavity is filled completely and neither can you be sure that insulation will not sag in time and leave voids in the cavity.

JimmyMW

srf wrote: »

Hi Im back
If you use 110mm kingspan insulation in a 150mm cavity wall it will give you a U value for the wall of 0.15 and if you increase the insulation to 120mm it will give you a U value of 0.14
As far I can work out this is similar to what you will get with a pumped 200mm cavity. You will have made a saving of the use of special wall ties as the standard one will do in the 150 cavity. you will also save by not having to increase your foundation sizes.
I am convinced that the 150mm cavity is a better option with the rigid insulation as it also eliminates the risk of dampness.
ps I have no afiliations with any insulation company.

People often state the cost of the wall ties, and quote that they are 3 times the cost, however you must look at the overall cost of the ties, i believe the standard wall tie is €0.23 + VAT and one for a 200mm cavity is €0.60 + VAT, on a house with 700 wall ties thats a difference of €318.57 on the entire house which IMOH is not a huge difference. Obviously foundations and rising wall depth are site specific, however I would like to see the actual differance in cost of a 350mm wide wall or a 400mm wide wall, I cant imagine it would be any massive amount.

JimmyMW

srf wrote: »

Just one note of caution is that you cannot be certain that the cavity is filled completely and neither can you be sure that insulation will not sag in time and leave voids in the cavity.

Thermal imaging cameras will tell you if the cavity is filled or not, and the agreement cert certifies the product for use, sagging is addressed in the cert if memory serves me right.

MicktheMan

JimmyMW wrote: »

Thermal imaging cameras will tell you if the cavity is filled or not, and the agreement cert certifies the product for use, sagging is addressed in the cert if memory serves me right.

And just to add to this...
if the TI survey shows up voids, this can be readily rectified, not so with poorly installed rigid boards.