Engineering brick are also resistant to soil contamination and waste. Manholes and chimneys built with engineering brick get Sulphacrete cement in the mortar for resistance to soot and coal, plus human faeces.
Other facing brick and some common have that 3 hole frog as well though.
Any good brickie building a buttress with those brick will have frogs solid filled with mortar for strength.
Other facing brick and some common have that 3 hole frog as well though.
Any good brickie building a buttress with those brick will have frogs solid filled with mortar for strength.