Identifying material on masonry wall

[phloaw]

The inner side of an exterior wall in my house has, behind the plasterboard, a kind of masonry which I'd like to identify.
I attach pictures.
It looks like concrete but it's quite easy to drill: I can very easily drill it with a 2mm wood/metal drill bit in a HAND (i.e., not electric) drill.
This material is at least 5cm thick (maybe more), as inferred from the hole I drilled.
So, what's the name of that substance? Is it safe to hang heavy stuff (e.g., a radiator) to it using rawlplugs?

Thanks!

 

[stuart45]

Could be AAC blockwork This is quite common on 1970 and later houses.

 

[jeds]

What's the details of your house; type, age, etc? Or a photo so we can identify the type.
stuart/ I'm not sure it's aac block. You'd see the joints.

 

[phloaw]

What's the details of your house; type, age, etc? Or a photo so we can identify the type.
stuart/ I'm not sure it's aac block. You'd see the joints.

It's a terraced house, two floors, built in the '70's (probably second half).

 

[^woody^]

Aerated block, aka Thermolite.

It can be fixed to, but fixings can be tricky due to the softness of the block - it's easy to widen the hole slightly when drilling causing the plug to be loose.

I always use either some expanding polyurethane glue in the hole, or Fischer "Wet n Fix" pads. But some PVA or tube adhesive will do.

 

[jeds]

I was thinking aac slabs but they were used more in the 50s and 60s. To be sure I'd need to know the exact house type. It could be blocks but they would have to be large ones, otherwise you'd see the joints. In any case it sounds like some sort of aac material, which is basically the same as modern thermal blocks except you know the exact quality of modern blocks. It should be fine for fixing radiators. Maybe just add a couple of extra fixings for the large ones.