DYSON cavity wall insulation

Brookebaloo

Hello,

I've just had my whole house cavity wall insulated. A guy was cold calling and advised he was a registered surveyor. He advised our loft was ok so just walls needed. I did a bit of research on this company and they had good feedback. However, whilst the process was just happening on the house, 2 separate passers by stopped and alarmed me with their tales of how they had to both have their insulation ripped out as it was causing damp to their houses. (they did say it was the old polestyrening insulation). I thought this was uncanny so asked the technician if this was true, he went sheepish and simply told us that old 'stuff' has since been banned and we would be ok as he was using 'rock wool'. Also he advised we would need a wall vent in the front room due to our fire. (we do have a floor vent, but hubby told him this was coming up when we replace solid oak floors to carpet). My issues with this wall vent is its ugly, and as i put my hand infront of it, there is such a draft so where i hope to save on heating, will this vent work the opposite way???

Just worried now a simple idea to save mone may end up costing more in the long run!!!

happy weekend to you all xx

WestonDave

There was a problem with an old form of insulation (it wasn't polystyrene as that is still used) - blown foam I think which formed a bridge between the outer wall and the inner wall so allowing damp across. That particular stuff isn't used anymore but because of it, there is some scepticism about cavity insulation. I've had mine done with polystyrene beads (which allow an air gap like rock wool and so allow any moisture in the cavity to drain - the solid foam stuff didn't) a couple of years ago - we know have less damp problems because ours were previously caused by condensation on cold walls rather than penetrating damp etc.

You will need to keep an air vent if you have any form of gas or solid fuel fire in the room unless it has a sealed flue which prevents any gases coming into the room. The alternative is to die of carbon monoxide poisoning. In any event you need some fresh air in the house to prevent humidity levels building up and causing condensation problems.

Brookebaloo

[QUOTE=WestonDave;47140257)

You will need to keep an air vent if you have any form of gas or solid fuel fire in the room unless it has a sealed flue which prevents any gases coming into the room. The alternative is to die of carbon monoxide poisoning. In any event you need some fresh air in the house to prevent humidity levels building up and causing condensation problems.[/QUOTE]

Thanks - i meant with the air vent, i now wish we would have refused the wall vent and instead stuck with the floor one, as that isn't as obvious, and strangely doesn't seem as 'drafty'. I might get hubby to brick the new wall one back up and then simply stick to floor (if this is still suffice with CWI)

Brummie71

Brookebaloo wrote: »

Thanks - i meant with the air vent, i now wish we would have refused the wall vent and instead stuck with the floor one, as that isn't as obvious, and strangely doesn't seem as 'drafty'. I might get hubby to brick the new wall one back up and then simply stick to floor (if this is still suffice with CWI)

The air vent is a legal requirement to ensure that there is enough ventilation to a room with any form of combustion appliance, given that death isn't usually a positive option.

Dyson are a reputable firm and providing the wall was properly surveyed and the insulation properly installed, then there shouldn't be a problem. There are some designs of properties that aren't suitable and some locations that don't suit cavity insulation, but the surveyor should have been clear on that.

Because uninsulated walls are colder, filling the cavity can often resolve condensation damp problems.