>>213548766 (OP)
I've never seen those and I don't think they're even legal to use in homes, we use the thick concrete ones and cover them in a layer of cement
>>213553216
No. These open spaces inside of bricks are useful in tropical lands as air mattress to control the temperature of walls during days and nights.
>>213548766 (OP)
I just found out that Brazilians don't pour cement in those blocks. Meanwhile we do here, which ends up in the structure feeling as hot as an oven. I often wonder why we won't stop pouring them with cement.