Building With Bricks – Joint Types

When building with bricks, there are many types of brick joint you can use, each with it’s own specific purpose.

Flush joints

The mortar is cut flush to the outer face of the bricks with the trowel. Bricks that do not have a flat face will likely be hard to flush neatly.

Rolled joints

A round bar is used to press in the mortar. Some bricklayers use a short length of garden hose to do this kind of joint but this can result in a coarse finish to the mortar. A steel tool will give a very smooth finish.

Weather joints

This type of joint allows rain water to drip down the face of the bricks and slow water absorption.

Struck joint

This is constructed making use of the trowel and only horizontal joints are struck.

Heavy bagging

The wall is lightly sprayed with water and smudged with a hessian bag in which mortar is placed. This will leave 1 or 2mm of mortar on the face of the wall. With a thin application of mortar, swirls or other patterns can be achieved.

V joint

A special square-edged tool is used to rake out mortar leaving a V-shape.

Raked joint

Mortar is raked out with a tool to a maximum depth of 10mm.

Light bagging (smudging)

A sponge or hessian bag is rubbed over the face of the wall whilst the mortar is still wet.


Mortar that oozes out of the joints is tooled flat. Alternatively, the brickie finishes all joints flush and goes over the entire job at the end to tool mortar over the flush joints.

Ooze joint

Excess mortar that oozes out of the joints is left in place.

It’s important that mortar joints are finished evenly throughout. Tooled joints effectively compress the mortar and make it extra weatherproof. Rolled joints are less likely to permit mortar to break than raked joints, thus making them appropriate for harsh coastal conditions where salt causes the mortar to break down. Adding colour to mortar can sometimes affect the bonding properties of the mortar.

Some joints, like parge, take a considerable time to do so the bricklayer must be told this in advance of pricing the job. The sort of brick (clay, cored, solid, lime silicate or concrete) as well as the size of the brick will also affect the rate the brickie charges.

A popular area of dispute between clients and builders is the variation in mortar joints of brickwork. The Australian Standards specify a maximum variation of plus or minus 3mm over a three metre length of bedding joint and a variation from 5 to 20mm for perpendicular joints. Ideally, all joints ought to be close to 10mm and a bricklayer would not be proud of workmanship which only just complied with the Australian Standards. If bricks are handmade, rumbled or clinker types then discrepancies in mortar widths will be less obvious but if the bricks are evenly sized and have sharp, square edges then the outcomes will be disappointing. If mortar widths are likely to be an issue then the bricklayer will notice this at the beginning of the job and need to advise the builder who will then have the brick manufacturer assess the size variation of the bricks.

As a result of the wide variation possible in brick colours, it is wise to visit the brickyard and make a particular batch selection. The batch you choose is going to be put to one side until your builder calls for their delivery to site. While at the brickyard check that the specific bricks you’ve selected have not had any problems. Some bricks with an excess of lime in the clay have been known to ‘pop’ or exfoliate when the globules of lime become wet and expand. When popping occurs it leaves white lime spots on the bricks. Ask the brick supplier for numerous addresses of homes that have utilized your preferred brick and visit them just before confirming your selection. Comparing various mortar colours is also useful as they can give a completely different appearance to a wall. Combining two or extra brick types for instance standard and double size bricks or colours can create fascinating features but this will need special care by the bricklayer to accomplish the desired effect. It’s also worth checking if the brick supplier has specific window sill bricks and squint bricks that can be used on 45° corners. If matching squint bricks are not accessible then the bricklayer will need to cut solid bricks to suit. Sills may be made by laying the standard brick on its edge and sloping it out. However a sill is created, it is crucial that it slopes outwards so that rainwater can drain away.