Five (5) rules for Bricklayers, “IN ORDER OF IMPORTANCE”, that will help prevent mortar and brick damage when cleaning
ALL BRICKS MUST BE LAID CLEAN. Especially concrete blocks, concrete & dry pressed bricks.
– These edges must be sharp & clearly visible without any traces of mortar on them.
– N.B. Only milky mortar smear should be left on the brick or block face.
– Then use a damp sponge for a perfect finish. DO NOT USE A WET SPONGE.
Use the 9:2:1 AS 3700 M2 mix. 9 Sand : 2 Lime: 1 Cement
– Buckets are best. The standard practice of using a number of shovels of sand to one bag of cement makes – inconsistent mixes. Melbourne mortars are mixed too hard and they can vary from being too hard through to being too soft on the same house.
No plasticiser chemicals – Use lime instead!
Remove all scaffold splatter from the bricks and all mortar droppings on the wall & the slab.
Always cover top course in wet weather to stop bricks from staining.
N.B. Plasticisers and lime replacements change mortar and make it harder to clean as they :
Make mortar lighter, harder and more brittle by making small bubbles in the mortar and this reduces the water content up to 30-40%
They coat the mortar with a waterproof layer that prevents acids from working.
They contract, tighten and harden mortar much faster making it impervious to acid cleaning
They have a glue that makes mortar stick much tighter to the bricks which acids cannot clean.
Chemical plasticisers do not react with acid and make sticky extremely hard mortar.
Our field tests and experience have proved even if you only use 1/4 of the recommended amount of Plasticizer it will make bricks (and tools) uncleanable.
Plasticized mortars with Lime added seem to react and become far too hard
Plasticisers added to the premix water will conflict with lime and the combination will make a sticky unworkable and unusable mix in the mixer.
We recommend considering the following points if you want to use plasticizers:
– Consider adding plasticised water at the end if you have to add them at all.
Final Caution. You may fail the mortar tests if you use plasticizers or lime replacement chemicals:
Plasticizers and Lime replacements are chemicals that are used to replace or reduce lime, and they will reduce the amount of calcium oxide (CaO) in the mortar which is a measure of limestone or (CaCO3). This may lead to mortar test failures as Builders test for CaO to check if the mortar passes the mortar test. If it fails they may back charge the brick layer for the repointing costs.