Cavity wall insulation
Discussion
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Does anyone know how this works? do they come to you house and drill holes in the walls and pump 'stuff' in?
why is it relatively cheap?
i'll be honest i don't particularly understand wall insulation other than new build!
Does anyone know how this works? do they come to you house and drill holes in the walls and pump 'stuff' in?
why is it relatively cheap?
i'll be honest i don't particularly understand wall insulation other than new build!
Yup, cavity wall insulation of this type into an existing building will be blown in through small holes drilled in your walls from the outside. They then plug the holes up with silicone / mortar depending on where they drilled.
Cheap because there are loads of grants available from govt? But perhaps they have more fitters than jobs?
Cavity wall insulation is OK for perfect conditions, but if you have problems with poor ventilation / decaying wall ties / blocked cavities / blocked air bricks, it can result in these defects showing up as damp.
Mike
Cheap because there are loads of grants available from govt? But perhaps they have more fitters than jobs?
Cavity wall insulation is OK for perfect conditions, but if you have problems with poor ventilation / decaying wall ties / blocked cavities / blocked air bricks, it can result in these defects showing up as damp.
Mike
GuinnessMK said:
Yup, cavity wall insulation of this type into an existing building will be blown in through small holes drilled in your walls from the outside. They then plug the holes up with silicone / mortar depending on where they drilled.
Cheap because there are loads of grants available from govt? But perhaps they have more fitters than jobs?
Cavity wall insulation is OK for perfect conditions, but if you have problems with poor ventilation / decaying wall ties / blocked cavities / blocked air bricks, it can result in these defects showing up as damp.
Mike
very helpful thank you.Cheap because there are loads of grants available from govt? But perhaps they have more fitters than jobs?
Cavity wall insulation is OK for perfect conditions, but if you have problems with poor ventilation / decaying wall ties / blocked cavities / blocked air bricks, it can result in these defects showing up as damp.
Mike
GuinnessMK said:
Yup, cavity wall insulation of this type into an existing building will be blown in through small holes drilled in your walls from the outside. They then plug the holes up with silicone / mortar depending on where they drilled.
Cheap because there are loads of grants available from govt? But perhaps they have more fitters than jobs?
Cavity wall insulation is OK for perfect conditions, but if you have problems with poor ventilation / decaying wall ties / blocked cavities / blocked air bricks, it can result in these defects showing up as damp.
Mike
We had an inspection for this and they refused to do it becuase of some damp in the loft.Cheap because there are loads of grants available from govt? But perhaps they have more fitters than jobs?
Cavity wall insulation is OK for perfect conditions, but if you have problems with poor ventilation / decaying wall ties / blocked cavities / blocked air bricks, it can result in these defects showing up as damp.
Mike
Anyone know the best solution for this - ie Airbricks on each gable (detached house), or holes under the eaves etc ?
barney123 said:
GuinnessMK said:
Yup, cavity wall insulation of this type into an existing building will be blown in through small holes drilled in your walls from the outside. They then plug the holes up with silicone / mortar depending on where they drilled.
Cheap because there are loads of grants available from govt? But perhaps they have more fitters than jobs?
Cavity wall insulation is OK for perfect conditions, but if you have problems with poor ventilation / decaying wall ties / blocked cavities / blocked air bricks, it can result in these defects showing up as damp.
Mike
We had an inspection for this and they refused to do it becuase of some damp in the loft.Cheap because there are loads of grants available from govt? But perhaps they have more fitters than jobs?
Cavity wall insulation is OK for perfect conditions, but if you have problems with poor ventilation / decaying wall ties / blocked cavities / blocked air bricks, it can result in these defects showing up as damp.
Mike
Anyone know the best solution for this - ie Airbricks on each gable (detached house), or holes under the eaves etc ?
_Batty_ said:
barney123 said:
GuinnessMK said:
Yup, cavity wall insulation of this type into an existing building will be blown in through small holes drilled in your walls from the outside. They then plug the holes up with silicone / mortar depending on where they drilled.
Cheap because there are loads of grants available from govt? But perhaps they have more fitters than jobs?
Cavity wall insulation is OK for perfect conditions, but if you have problems with poor ventilation / decaying wall ties / blocked cavities / blocked air bricks, it can result in these defects showing up as damp.
Mike
We had an inspection for this and they refused to do it becuase of some damp in the loft.Cheap because there are loads of grants available from govt? But perhaps they have more fitters than jobs?
Cavity wall insulation is OK for perfect conditions, but if you have problems with poor ventilation / decaying wall ties / blocked cavities / blocked air bricks, it can result in these defects showing up as damp.
Mike
Anyone know the best solution for this - ie Airbricks on each gable (detached house), or holes under the eaves etc ?
Take a careful look at what is causing the dampness in the roofspace.
If it's condensation, you need to look at removing steam from any wet areas in the house from source with a mechanical extract fan or similar.
If the roof is wet, you need to look at your slate/rooftile detailing and the condition of adjacent roof flashings etc.
Once you have sorted the above,your proposed eaves ventilation will be effective.
If it's condensation, you need to look at removing steam from any wet areas in the house from source with a mechanical extract fan or similar.
If the roof is wet, you need to look at your slate/rooftile detailing and the condition of adjacent roof flashings etc.
Once you have sorted the above,your proposed eaves ventilation will be effective.
I asked a question aobut cavity wall insulation a few days ago, but since noone answered, I'll try again...
I always understood that if you put something in the cavity it will provide a bridge for damp to get from the outer wall to the inner wall, so why is cavity wall insulation such a good thing? What is the definitive truth? Will CW insulation make a cold damp house worse, or better?
I always understood that if you put something in the cavity it will provide a bridge for damp to get from the outer wall to the inner wall, so why is cavity wall insulation such a good thing? What is the definitive truth? Will CW insulation make a cold damp house worse, or better?
MitchT said:
I asked a question aobut cavity wall insulation a few days ago, but since noone answered, I'll try again...
I always understood that if you put something in the cavity it will provide a bridge for damp to get from the outer wall to the inner wall, so why is cavity wall insulation such a good thing? What is the definitive truth? Will CW insulation make a cold damp house worse, or better?
I have lived in different houses. One a solid brick house that was cold and damp. My current has cavity walls.I always understood that if you put something in the cavity it will provide a bridge for damp to get from the outer wall to the inner wall, so why is cavity wall insulation such a good thing? What is the definitive truth? Will CW insulation make a cold damp house worse, or better?
There should be no damp in a house with cavity walls. Solid walls allow damp to wick through whereas cavity walls dont or shouldn't. By adding foam insulation you are adding an extra blanket of warmth but with the downside of possibly allowing damp to wick through. Your external damp measures need to be in good condition. Windows painted and windowframes sealed. Walls painted and in good condition. No leaking gutters or running water from overflows. Damp course in working condition.
Wall ties need replacing if they have corrided which they may if external damp and condensation has corroded them. The wall ties are simply to keep the structure stable and stop the walls bulging apart.
I have heard bad reports of cavity walls being filled with foam. My concern is how do you know if you are getting what you pay for. How do you know the whole structure has been insulated and not just a couple of metres around the foam inlet?
GuinnessMK said:
Yup, cavity wall insulation of this type into an existing building will be blown in through small holes drilled in your walls from the outside. They then plug the holes up with silicone / mortar depending on where they drilled.
mark69sheer said:
I have heard bad reports of cavity walls being filled with foam. My concern is how do you know if you are getting what you pay for. How do you know the whole structure has been insulated and not just a couple of metres around the foam inlet?
Good question.
s4avant said:
Take a careful look at what is causing the dampness in the roofspace.
If it's condensation, you need to look at removing steam from any wet areas in the house from source with a mechanical extract fan or similar.
If the roof is wet, you need to look at your slate/rooftile detailing and the condition of adjacent roof flashings etc.
Once you have sorted the above,your proposed eaves ventilation will be effective.
It appears to have happened when we a) stuck down some more loft insulation and b) put pvc soffits all around. The house had quite a few holes here and there - pipe holes for the old cold water storage tank overflow. Once we remove all these we must have effectively sealed the loft and initially there was loads of condensation on the underside of the roof. I pulled back the loft insulation and this has reduced the dampness, but I must need some more ventilation.If it's condensation, you need to look at removing steam from any wet areas in the house from source with a mechanical extract fan or similar.
If the roof is wet, you need to look at your slate/rooftile detailing and the condition of adjacent roof flashings etc.
Once you have sorted the above,your proposed eaves ventilation will be effective.
Sorry for hijacking your post !!
Busamav said:
In addition to the eaves ventilation already mentioned , it is important to have a high level cross flow too.
Your earlier mention of a vent in each gable would be perfect , as long as it is located at high level.
What sort of vent is best - an airbrick or just using a core drill and sticking a vent kit in ?Your earlier mention of a vent in each gable would be perfect , as long as it is located at high level.
My 1938 house was done by Cape Industries in 1981. They used urea formaldehyde foam pumped in at about 1 metre centres. They put pieces of wood in nearby holes and watch them move as the foam rises past the holes thus confirming that the whole wall is treated. For moderate exposure sites and below, UF was said to be fine (by Agrement Board - the approvals body), and for exposed sites they recommended mineral fibre. If the material is essentially hydrophobic, i.e. doesn't absorb water, it won't wick moisture through. There are degrees of resistance and that's why the recommendations vary with site. I do not regret for a second having mine done and the only problem I have had is wasps nicking the foam to make a nest (I assume) from an airbrick aperture! Small size mesh across it sorted that.
barney123 said:
Busamav said:
In addition to the eaves ventilation already mentioned , it is important to have a high level cross flow too.
Your earlier mention of a vent in each gable would be perfect , as long as it is located at high level.
What sort of vent is best - an airbrick or just using a core drill and sticking a vent kit in ?Your earlier mention of a vent in each gable would be perfect , as long as it is located at high level.
MrV said:
barney123 said:
Busamav said:
In addition to the eaves ventilation already mentioned , it is important to have a high level cross flow too.
Your earlier mention of a vent in each gable would be perfect , as long as it is located at high level.
What sort of vent is best - an airbrick or just using a core drill and sticking a vent kit in ?Your earlier mention of a vent in each gable would be perfect , as long as it is located at high level.
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