Insulation for 9in Cavity Block

[godthe]

I am going to build an extension at the back of the house with just 9in cavity block. Is a 12mm slab with 50mm insulation attached good enough for wall insulation. If so can someone tell me the cheapest place to purchase these in dublin please

 

[sydthebeat]

I am going to build an extension at the back of the house with just 9in cavity block. Is a 12mm slab with 50mm insulation attached good enough for wall insulation. If so can someone tell me the cheapest place to purchase these in dublin please

cavity block with internal 'drylining' is a bad construction godthe..... is there any reason you cant go with a double leaf cavity wall?

 

[sydthebeat]

to godthe.....

DO NOT USE A PRODUCT THAT HASNT BEEN PROPERLY TESTED AND CERTIFIED FOR USE IN THE IRISH CLIMATE.....


such as the product above....

 

[godthe]

Cost would be the main reason for using the 9in cavity. The house itself was built in the early 70s with cavities and there is no insulation on the inside. If a double leaf means 2 seperate walls with insulation between i would imagine it to be very expensive with a wider foundation and an extra wall.
Syd, do you think my extension would be cold using my original idea
Thanks for the help everyone

 

[wexford dude]

godthe,

I agree with Sydthebeat a cavity block wall for the external walls is the best option.The cost difference should not be that big.

If you insulate both sides of the inside leaf this system should pay for itself in heating costs.