Cavity wall inner skin - which blocks to use

[michaelds]

Hello. Our building regs states our inner skin should be 100mm Fibrolite or similar approved. It does not state the required strength i.e. 3.6 or 7.2N.

I would like to gain the benefit of someone's practical experience compared to internet theory!

For a residential 2 storey would you recommend using 7N blocks? I understand that Fibrolite's are classified as medium density. I am struggling to get to grips with the trade off between the insulation benefits (and practical handling) of a aerated lightweight block versus the fact that these blocks (I understand?) can be brittle and not ideally suited to hanging kitchen cabinets/TV's etc.

Finally "similar approved"...are there any non brand blocks with suitable properties that would save me a few pennies. If you know a cheap supplier in the Kent / South East area that would be an added bonus!

Thank you in advance for any advice you can offer.

Michael

 

[wrightwoodwork]

Google celcon they are one of the most common blocks of this kind they would be able to tell you which product to choose more than I can. Fixing into them is no different to fixing in ordinary bricks just keep the fixing away from the edges, timber pads where radiators go can be used dabs in areas that fixings go, plug and scrws,frame anchors,thunder bolts

 

[noseall]

3.5n fibolites or similar are ideal.

Celcon or similar aerated blocks are ok but are prone to cracking due to shrinkage or thermal movement. You would need to ensure that masonry is kept dry throughout the build. Difficult in this country at the best of times.

 

[michaelds]

3.5n fibolites or similar are ideal.

Celcon or similar aerated blocks are ok but are prone to cracking due to shrinkage or thermal movement. You would need to ensure that masonry is kept dry throughout the build. Difficult in this country at the best of times.

Thank you for your help. So 3.5N are sufficient strength even for an inner skin on a double storey?

 

[stuart45]

2.9 is enough.

 

[noseall]

Thank you for your help. So 3.5N are sufficient strength even for an inner skin on a double storey?

Ii is what they were invented for.

 

[michaelds]

2.9 is enough.

Perfect. Any 'good value' alternatives to Fibrolite's?

 

[stuart45]

A lot of builders have moved away from using AAC blocks because of shrinkage cracking, poor adhesion etc, but if you don't use too strong a mix when laying them you can avoid the problems.
It's just a case of looking around for a good deal on them.