How does the Hydraform HF140mm brick differ from the Hydraform HF220mm brick?
A. The HF220mm brick is mostly dry-stacked, this means that it does not need mortar between every course of brick work. The HF140mm brick is first dry-stacked and then a slurry made from fine sand and cement, is poured though the cavity on the bricks, this locks the structure together creating a strong firm wall.
