3.6N Aircrete blocks. Where are they used?

[flanagaj]

I am just going back through my estimators quote and am trying to workout where the 3.6N Aircrete blocks they have specified are used.  The quantity seems to indicate that they have specified them for the ground and first floor cavity walls and only specified the 7.3N blocks for the internal ground floor blocks walls.

 

Is this normal practice or can you use 7.3N blocks for for everything internally and avoid using the expensive Aircrete blocks?

[ADLIan]

Aircrete blocks in external walls to help achieve Uvalue. Check construction, insulation and required Uvalue. Cheap & cheerful standard concrete block for inner walls, density helps with acoustics.

[Super_Paulie]

I use air blocks or thermalites when I build most internal walls. Easier to manage, weigh next to nothing, can be cut with a saw. Added bonus of increased insulation values, what's not to like.

[flanagaj]

Ok, thanks.  I always thought that Aircrete blocks looked like below.  What are you using in the above image?

[dpmiller]

is "aircrete" actually noted tho? Ordinary blocks can come in 3.6N too...

[Russell griffiths]

I personally would put them on face book market place and let some other idiot use them. 
get a proper block. 

[Super_Paulie]

3 hours ago, flanagaj said:

Ok, thanks.  I always thought that Aircrete blocks looked like below.  What are you using in the above image?

 

actually, ive told you a load of boll0cks there. I used full "normal blocks" in the main wall and then used therms* above "flat" as they bridge the cavity and into the old roof space. I wanted that additional thermal protection at the top, plus they support no weight. 

 

*it was the skanky Wickes alternative as i coudlnt get therms the same day. Edges like razor blades.

 

Edited November 21, 2025 by Super_Paulie

[Mr Punter]

3 hours ago, flanagaj said:

Ok, thanks.  I always thought that Aircrete blocks looked like below.  What are you using in the above image?

 

Yes and the pattern of scribble lines indicate the block strength.