A Mortar Bee is a species of bee that has enlarged rear legs, the Mortar Bee uses these hind legs to remove mortar from joints of brickwork.

Mortar bees prefer to work in the softer mortar mixes and can cause significant structural damage.

The mortar bee will remove mortar from the joints of brickwork, this will enable moisture to enter the wall cavity and can cause some areas of collapse of brickwork when the damage is advanced.

Any brickwork with soft mortar is susceptible to mortar bee attack and when signs of mortar bee damage are located then the mortar bees are always considered to be active.

The colour of brickwork is often associated with mortar bee attack, as lighter bricks will often have a softer mortar with less cement content to match the colour of the bricks.

Blonde bricks and terracotta colored brickwork appear to have a higher occurrence of mortar bee attack than bricks with a darker finish.

Our experience is that Mortar Bee damage is not a common pest, we find that our records indicate that Mortar Bee damage has been found in about 3% of all the inspections we have carried out on buildings in the Sydney area.

To repair Mortar Bee damage it is recommended to point the mortar joints of the brickwork with a new mortar that may contain a higher percentage of cement, this will make the mortar to hard for the Mortar Bee to effectively remove with it's hind legs.

We have attached a number of photos from a recent inspection carried out in the Sydney suburb of Oatley, in NSW Australia. Inspection was carried out on the 30th January 2001


These four pictures illustrate the damage caused by Mortar Bees, the Mortar Bees have excavated the mortar from the joints of the bricks, the brick closest to the timber window has had the majority of the mortar removed and the brick was already loose when we carried out the inspection.

It would appear the when the Mortar Bee attack is advanced then the natural erosion of mortar from the brick joints in the immediate area will also increase.

Mortar Bee damage should be repaired immediately, once a single brick is loose then adjoining bricks can easily loosen, when a large area of brickwork is loose the immediate structure may fail.

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Stephen Koelewyn - NSW Builders Licence 45109c - Building Consultant Licence BC213 (Now Obsolete in NSW) - Pest Control Licence - NSW 15-001467-004

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Last modified: 31 July, 2022->->->