Mounting Pull Up Bar to Breeze Block Wall

stuart45

We normally use 7N below DPC and 3.5N above.

weeg

stuart45 said:

We normally use 7N below DPC and 3.5N above.

Interesting. We specify the exact opposite! (although that's a recent change to using thermalite below suspended slabs). 

stuart45

Some of the Thermalite and other AAC trench blocks here are 3.6N, high strength ones are 7.3N . Not sure why the higher strength blocks would be used over DPC and the weaker ones under. The dense concrete 7.3's are more difficult to work with. OK for a couple of courses up to DPC, but harder work to build a higher wall with. 

weeg

stuart45 said:

Some of the Thermalite and other AAC trench blocks here are 3.6N, high strength ones are 7.3N . Not sure why the higher strength blocks would be used over DPC and the weaker ones under. The dense concrete 7.3's are more difficult to work with. OK for a couple of courses up to DPC, but harder work to build a higher wall with. 

Thermalite below slabs for thermal reasons (although NHBC didn't used to allow it). I've never really questioned why we use 7N block. Robustness, I assume, plus it's better in bearing and for lateral load. But probably it's because 'it's what we've always done' and relates to a code which was withdrawn while I was in nappies.  I do know that pretty much all the mass housebuilders use the same specs though, at least in Scotland.

stuart45

It's different to England. The NHBC guidance NHBC Standards 2011 (nhbccampaigns.co.uk)

weeg

stuart45 said:

It's different to England. The NHBC guidance NHBC Standards 2011 (nhbccampaigns.co.uk)

No, same standards up here. I was mislead by a client asking for a change. Now I need to actually go and chase something! 
And, OP, please accept my apologies for the threadjack!