pumped wall insulation

LennyandMo

Is there different types of pumped insulation for walls? people have mentioned different coloured beads?

BarneyMc

I think something like this is what you're after: http://www.kingspanecobead.com/index.php/u-value

The thermal conductivity is 0.033W/m.K

A lesser white bead might still be in use but doesn't have the same thermal performance.

Anyway check the thermal conductivity before making your decision. Also make sure it's fully approved by IAB/BBA for use.

LennyandMo

Thanks barneymc, so I would be better of with solid sheet partial fill type insulation do you think in a 150mm cavity? I don't want insulated boards inside

BarneyMc

LennyandMo wrote: »

Thanks barneymc, so I would be better of with solid sheet partial fill type insulation do you think in a 150mm cavity? I don't want insulated boards inside

Have you started building yet? I'd go with a wider cavity and pump it with beads if you haven't started your build. I'm no expert though.

prewtna

I had a quick read through the spec for that bead insulation. I presume it applies to all suppliers not the just one above.

So, here's my stupid question of the day!

When they say 'tightly packed honeycomb matrix with a water based adhesive' - is the 'water based adhesive' a weak point in the system?

What i mean is - if it is water based and you place it in the cavity of a cavity wall, is there a chance the adhesive will;

A) become compromised by a wet outer leaf of blockwork and

if thats the case, whats to stop water tracking from the wet outer leaf all the way through the cavity wall to the interior of the building?

We have had issues where schools in particular have installed new bead insulation in existing cavities and lo and behold a while later they have dampness on the walls internally (where it didn't exist previously). I notice the same on the house i live in at present. (I rent) The landlord got the cavities pumped last spring and there appears to be dampness forming in patches on the inner face of the outer walls now. I know people will say ventilation is a problem - but i can assure you all in this case its not.

Should we all be wary of the blown bead? I feel the cavity wall is a bloody good solution for our Irish weather, given the amount of rain and wind we get, and I must confess I am skeptical of anything that crosses the cavity (except wall ties!!)given the propensity for water to find a way in even when it appears impossible.

MicktheMan

prewtna wrote: »

We have had issues where schools in particular have installed new bead insulation in existing cavities and lo and behold a while later they have dampness on the walls internally (where it didn't exist previously). I notice the same on the house i live in at present. (I rent) The landlord got the cavities pumped last spring and there appears to be dampness forming in patches on the inner face of the outer walls now. I know people will say ventilation is a problem - but i can assure you all in this case its not.

Do you have any pics of the affected areas?
With the right tools, it is relatively easy to distinguish between damp on walls due to a lack of appropriate ventilation and penetrating damp.

hexosan

prewtna wrote: »

I had a quick read through the spec for that bead insulation. I presume it applies to all suppliers not the just one above.

So, here's my stupid question of the day!

When they say 'tightly packed honeycomb matrix with a water based adhesive' - is the 'water based adhesive' a weak point in the system?

What i mean is - if it is water based and you place it in the cavity of a cavity wall, is there a chance the adhesive will;

A) become compromised by a wet outer leaf of blockwork and

if thats the case, whats to stop water tracking from the wet outer leaf all the way through the cavity wall to the interior of the building?

We have had issues where schools in particular have installed new bead insulation in existing cavities and lo and behold a while later they have dampness on the walls internally (where it didn't exist previously). I notice the same on the house i live in at present. (I rent) The landlord got the cavities pumped last spring and there appears to be dampness forming in patches on the inner face of the outer walls now. I know people will say ventilation is a problem - but i can assure you all in this case its not.

Should we all be wary of the blown bead? I feel the cavity wall is a bloody good solution for our Irish weather, given the amount of rain and wind we get, and I must confess I am skeptical of anything that crosses the cavity (except wall ties!!)given the propensity for water to find a way in even when it appears impossible.

What size were the cavities that were pumped in the school and where you rent as I believe this has a bearing on water tracking across the cavity.

prewtna

typically 100mm cavity - both in the schools and in the house.

50mm of insulation would have been present already.

wont get photos up of the areas affected.

would there be a solution - assuming it is water ingress rather than dampness from condensation? - re-render the outside?

maybe the beads haven't totally filled all areas when being pumped and that might help in water ingress? if so i guess thermal imaging would highlight this and if thats the case - the bead installers could be getting a few 'strongly worded letters'!

BryanF

prewtna wrote: »

typically 100mm cavity - both in the schools and in the house.

50mm of insulation would have been present already.

wont get photos up of the areas affected.

would there be a solution - assuming it is water ingress rather than dampness from condensation? - re-render the outside?

maybe the beads haven't totally filled all areas when being pumped and that might help in water ingress? if so i guess thermal imaging would highlight this and if thats the case - the bead installers could be getting a few 'strongly worded letters'!

have you considered that this could be caused by the poor quality of the original wall/cavity construction, perhaps where mortar snots cross the wall cavity. These were probably not such an issue with min insulation as the movement of air in the cavity took care of it. now that the cavity is insulated, the thermal bridges or damp bridges are heightened

btw are either of these walls brick outer leaf?

prewtna

BryanF wrote: »

have you consider that this could be cause by the poor quality of the original wall/cavity construction, perhaps where mortar snots cross the wall cavity. These were probably not such an issue with min insulation as the movement of air in the cavity took care of it. now that the cavity is insulated, the thermal bridges or damp bridges are heightened

btw are either of these walls brick outer leaf?

that's a good point - the cavity was probably full of snots of mortar alright. In which case there is probably not much can be done - the thermal bridge is there to stay!

Yes the house has a brick outer leaf. forgive my ignorance - what difference would that make? perhaps more porous than rendered blockwork?

BryanF

prewtna wrote: »

Yes the house has a brick outer leaf. forgive my ignorance - what difference would that make? perhaps more porous than rendered blockwork?

from what I've read (quiet a while ago,so unfortunately I've no references to hand) and previous site observations on a particular project i came to conclusion that brick was not ideal for pumped cavity as brick is more porous than a continuous external render. Now some IAB certs will show its acceptable in sheltered areas but that rules out the guts of Munster, Connaught & Ulster

perhaps you'd tell us where in the country your projects are and what the IAB cert says as regards exposure?