Thermal Insulation

[Scott F]

Been to see a job new build which has blue polystryrene bricks ,has any one had any experience with these. did you wire the rings in 4ml for instance any advice apprieated. Also has any one have experience with class b cat ld3 fire alarm systems .Are they fairly simple to install or am i better off getting fire alarm installers in cheers

 

[Guest123]

Hey Scott.

Have a look at these, some good links and guides here.

Cheers.

Firesafe Fire Alarm Systems, Emergency Lighting, emergency signage, Health and Safety Equipment
Smoke Alarms, Fire and CO detection and fire protection specialists Aico Ltd

As for the poly blocks, never come across them but I would say you need to apply all the cable factors associated with thermal insulation but perhaps you would need to find out their actual thermal value from the manufacturer.

 

[lister]

poly blocks, you need to contact the manafacturer, (or a cable manafacturer) as a rule never let cables come into contact with polystyrene as it reacts with the pvc cable, you may have to use specialist cables?

 

[mrloy99]

poly blocks, you need to contact the manafacturer, (or a cable manafacturer) as a rule never let cables come into contact with polystyrene as it reacts with the pvc cable, you may have to use specialist cables?

I've not heard about polystyrene reacting with pvc before.Where did you read about that.I wouldn't mind reading up about that myself.

 

[Spudnik]

I've not heard about polystyrene reacting with pvc before.Where did you read about that.I wouldn't mind reading up about that myself.

Did a major kitchen refurb years ago that had wood panelling backed by thin polystyrene sheets.

The cables that it covered were practically glued to it.

 

[lister]

As far as i know its not mentioned in 7671 (certainly can't find the little rascal mentioned), its more of a building regs thing, if you google the key words you will find out more, insulation manafacturers worn about it (gypsom) , some polys are ok ie polyuerathane (spray foam) but polystyrene is a definate no.check what your blocks contain.

I have had this myself, i pulled up a water damaged chipboard floor layed on slabs of the stuff, it had only been down about 18 months and the cables that passed through it had already gone black and gooey.

I searched this forum and found this.

"In pvc cables a plasticiser is used to keep the cables flexible and its this plasticiser that migrates on contact with polystyrene causing the cable sheath to become sticky and eventually brittle."

 

[bahco]

sounds interesting

ive got to rewire a kitchen in a few weeks that is having poly backed plaster board fitted.

thanks for that

 

[mrloy99]

As far as i know its not mentioned in 7671 (certainly can't find the little rascal mentioned), its more of a building regs thing, if you google the key words you will find out more, insulation manafacturers worn about it (gypsom) , some polys are ok ie polyuerathane (spray foam) but polystyrene is a definate no.check what your blocks contain.

I have had this myself, i pulled up a water damaged chipboard floor layed on slabs of the stuff, it had only been down about 18 months and the cables that passed through it had already gone black and gooey.

I searched this forum and found this.

"In pvc cables a plasticiser is used to keep the cables flexible and its this plasticiser that migrates on contact with polystyrene causing the cable sheath to become sticky and eventually brittle."

wow that sounds scary and I've seen polystyrene used as insulation loads of times without precautions taken,they must all be in the same state as yours by now.

 

[kevinreilly]

Did a major kitchen refurb years ago that had wood panelling backed by thin polystyrene sheets.

The cables that it covered were practically glued to it.

yeah the pvc bleeds when in contact with polystyrene.

 

[Scott F]

cheers for the links lennie do you install these your self? fire safe products that is . If so am i right in that commisssioning is just filling in the certs and testing the smokes am full scope and hold 2391 so deemed competent in some peoples eyes