Any Negatives with Cavity Wall Insulation?

[Doctor Drivel]

My God. The house that Jack built!

[David Hansen]

On Tue, 20 Nov 2007 08:52:26 +0000 someone who may be Andy Cap wrote this:-

Do you? What are you up to to generate more than the 100 odd Watts per person of a person not doing energetic activities?

[David Hansen]

On Tue, 20 Nov 2007 08:03:04 +0000 someone who may be Derek Geldard wrote this:-

Ventilate.

[Chris J Dixon]

How long a vertical run is it sensible to have without any cable ties or other support?

PVC cable in contact with polystyrene insulation will be at risk of plasticiser leaching.

Chris

[Frank Erskine]

Does anyone use polystyrene CWI these days?

I thought it's nearly all rockwool.

[Steve]

Yes, if you have a suspended timber floor and if they don't sleeve the airbricks first, they are blocked-up by the insulation. In time the lack of underfloor ventilation will make the underfloor an ideal place to encourage the timber to rot.

Steve

[David Hansen]

On 20 Nov 2007 15:11:08 GMT someone who may be "Bob Eager" wrote this:-

In the case of low voltage cables there are questions of current carrying capacity being adequate if a cable is in free air but not adequate if the cable is in insulation.

Perhaps you could convince me that you know better then they do?

Extra low voltage cables and the like are unlikely to suffer the same problems, but it is rather easier to put them in a suitable duct. In my house there are two routes for services between the floors. Both are heavily used, including telephone, computer network, terrestrial television/radio and satellite cables; without mentioning the various pipes with water in them some or all of the time.

[The Natural Philosopher]

No one has suggested putting polystyrene in cavity walls.

[The Natural Philosopher]

Or polyisocyanurate.

[The Natural Philosopher]

The damp proof course is continous and goes ABOVE the airbricks. They cannot block.

[Steve]

Not in this house. I suspect in many others too.

Two separate DPCs with nothing whatsoever to stop crap or insulation blocking them, as I found out here.

Stop talking out of your arse.

Steve

[Mary Fisher]

No, only plus ones.

Mary

[Bob Eager]

In my case there was support.

I agree. But Drivel said it was wrong, period. He wasn't talking about whether there was any insulation.

[Bob Eager]

Not at all. I never mentioned low voltage cables. I was referring to extra low voltage cables.

Possibly, if a duct exists. In some case it is easier not to.

[Andy Hall]

You haven't had an accident with some roof timbers and a circular saw, have you?

Go on, you can admit it. You are among friends.....

[Doctor Drivel]

Matt, you need therapy.

[Steve Walker]

Or in my case, the electricity meter cupboard - the only single skinned section of the walls. Luckily it was a blown fibre, not foam.

SteveW