Tony Bryer wrote:
That wasn't uncommon in the 1930s, likewise partitions built of bricks
laid on their sides

When I helped my brother move his bathroom wall in his 1930s
ex-council house we went at it with sledge hammers and
arm-wrenchingly discovered it was built out of 12" x 8" x 4"
blocks of plaster, built straight on top of the timber floorboards.

JGH