Toplite lightweight block to build seating area in garden

Raymond2016

Hi all,

I have bought a pallet of Toplite lightweight concrete blocks to build a short sitting area in the garden. They are like those dense heavy concrete blocks but a lightweight version. They say that they are fine to use above and below the ground and outdoors etc. I was just planning on painting the external faces with a waterproofing mason art paint rather than rendering them.

I have now read some thoughts that they absorb water and can crack with the frost. Is there anything else I should do or should bother be okay?

Thank you

stuart45

You might find it difficult to get a correct answer on this question, as most builders would use concrete blocks in this situation, rather than AAC blocks. I've worked with AAC blocks since the mid 70's when they started to become used more commonly for the inner skins of cavity walls, but have very limited experience with them for garden walls etc.
Manufacturers claims are not always as accurate as first stated. Thermalite used to say that their blocks would take a fixing without the need for plugs for example.
I have found myself that using AAC blocks out side on a small duck house, the blocks became a bit more likely to crumble when taking a fixing, so if you use them some protection like masonry paint as you intended would probably do the job.