I don't see any other replies coming Bob so I'll offer this advice.
On a general note, lightweight materials tend to have less strength per volume than other materials.
Some concrete block products while offering good insulation properties, do not support point loads as well as more dense materials eg. ; -
- cannot take hanging side hung heavy doors for example, without special restraints [fire doors, security doors].
- do not have enough intrinsic load bearing capacity to be pared right back when making new opes [ope for rear extension without piers]
- cannot be use to carry a heavily loaded beam without special spreading courses below to distribute the load [clear span rooms with no returns or buttresses].
Sometimes these materials can be easily chased, but significantly weaken depending on the positioning of the chase, particularly horizontal chase.
Whatever about a 215mm solid block, I would be very wary about chasing even one side of a lightweight block, never mind both sides.
Because of this less dense property strength per cubic metre is reduced - I would therefore retain an engineer to advise on structure.
Two other issues may arise; -
- permeability to wind driven rain and
- poor sound absorption between internal spaces.
You might also want to try the Construction and Planning forum on boards.ie
Populated mainly by technicians, do read the posting rules before you post as mention of specific products can get a ban.
In your case I strongly suggest that you register and then PM one of the moderators with the question you hope to ask before posting.
You could also try Construct Ireland and seek out the Brendan Kelly posts referred to in this response there.
[broken link removed]
Sorry I couldn't be of more help.
ONQ.