4:1 Mortar Estimator
This calculator will provide the approximate quantities of sand & opc for Class II
mortar per square metre of metric brickwork
for brickwork & mortar info.
A more extensive mortar calculator is available at our Brick & block calculator and also at our cavity wall calculator.
Please enter the dimensions in the white fields below. The calculations will be
completed when you leave the last input field.
Natural materials such as clay bricks have characteristic variations in shade,
colour and texture. However because patching or colour banding would not be
desired in the finished work, it is important to blend the bricks.
Although this is carried out at manufacturing there is still a need to further
carry out this process on site, this is best achieved mixing from as many packs
as possible and mixing from corners rather than layers to maximise colour consistency.
The correct preparation is key to the overall aesthetics, durability, weather resistance
and structural performance. See our other
for further info on mortar.
In general terms the correct proportions of binders and sand is necessary for consistent
mortar strength, avoidance of colour variation and a good bond between brick & mortar.
This should be achieved by the use of batching boxes or buckets, avoid the use of shovels
for proportioning by volume.
- Mortar consistency In general, the correct mortar consistency is a
matter of the bricklayers judgement. However, if mortars are too wet at the
time of laying this can lead to staining of the brick edges and, in the worst
cases, runs of mortar can form on the face of the brick. Ideally, mortar should
'hang' on the trowel without being sticky, should spread easily and should not
ooze out of the joints when bricks are positioned.
- Docking It is accepted practice for bricks with a high absorbency
to be wetted prior to laying. This procedure adjusts the suction rate of the
brick to promote good adhesion between the brick and the mortar. However, bricks
should not be soaked during the process as this could lead to subsequent staining
problems. See above. Bricks with a low suction rate should never be wetted because
they might 'float'; mortar that is mixed too wet will have the same effect.
- Tooling The bricklayer uses his skill and experience in determining when
to begin tooling the joints after placing the bricks in mortar. Early tooling should
be avoided as this can produce a dragged effect on the mortar surface and the cement
fines may be drawn to the surface resulting in an unsightly patchy bloom on the
joints in the mature work.
- Winter working If the temperature of unhardened mortar is less than 40C,
the performance of the joints produced will be inadequate. Consequently, bricklaying
should stop when the air temperature reaches 30C and falling, unless the mortar
temperature can be maintained at a minimum of 40C until it has hardened.
Bricklaying can be resumed when the air temperature rises to 10C and is expected
to continue rising to above 30C over the bricklaying period.