Repairing External Cladding: Brickwork

James and Diana France have used cedar cladding to contrast with the areas of brick wall on their custon-designed self-build home. Read more about this self-build.

The majority of homes in Britain are built using at least some brickwork and as with most elements of all buildings, as they age, brickwork will begin to deteriorate. There are a number of causes for this deterioration and also a variety of solutions. The important factor is to identify the cause of the problem and to rectify it quickly before any lasting damage occurs.

ABOVE: Spalling – the crumbling of the face of the brick – can occur for a number of reasons, water ingress being a common culprit.

Causes of Brick Problems

Water Ingress

A particular problem on exposed areas of brickwork – such as that on upper floors and chimney stacks, and in areas close to downpipes – water ingress is one of the most common and potentially serious threats to brickwork. There are a number of reasons why your brickwork may be suffering from water ingress, including: wind-blown rain; condensation caused by poor ventilation; failure of rainwater goods; vegetation invading the brickwork; damaged mortar; and flawed copings, flashings or DPC.

Moss growth on bricks is a sign of water ingress and also, in fact, encourages more water to penetrate the building.

Salt

The most obvious sign of salts being present in your brickwork is efflorescence: a white, powdery deposit. Salt is actually a major cause of deterioration — the salt crystals expand and eventually force the structure of the brick apart.

Structural Faults

Cracked brickwork is often a sign of a structural problem, ranging from structural movement to tree roots causing havoc. Very minor cracks are usually superficial, and it is often not a problem to simply cut out the affected area and repoint it, although in some cases it may be necessary to replace the bricks. More serious cracks should be investigated by a professional.

Frost

Porous bricks are more susceptible to frost damage than denser styles. Frost damage occurs when water within the brick expands during freezing conditions.

Vegetation

If left unchecked, vegetation can cause serious damage to brickwork. Ivy in particular can be a problem, especially where the bricks are already in a state of disrepair, as the growth finds it easier to break into the surface and into the wall core.

Over time, mortar often falls out from between bricks. The new mortar you use must be appropriate to the age of the building.

How to Fix It

It is sometimes necessary to replace single bricks or small areas of brickwork, particularly where spalling has occurred. Replacement bricks should closely match the originals in colour, texture and size, and in some cases you might have to have them made. Reclaimed bricks are also available, but be sure to carefully inspect them for damage. In some cases it is possible to identify the manufacturer of a brick and the date it was made from a maker’s stamp.

If mortar has, over time, fallen out between bricks, you will need to repoint. Old mortar should be carefully raked out by hand, taking care not to damage the corners of bricks. The new mortar must be appropriate to the building. Traditionally, lime-based mortars were used, although from the late Victorian period onwards, cement-based versions were common. Cement mortar should not be used as a replacement for lime mortar as it will prevent water from escaping from the wall. As well as matching the new mortar to the original, the pointing technique used should also tie in with that used on the rest of the building.

ABOVE: Replacement bricks should closely match the originals. Reclaimed bricks are available, but you might find you will have to have new ones made.

Maintaing Brickwork

The most important thing to do is regularly check bricks for signs of deterioration.

Cleaning of bricks is a job which should be undertaken with care. The use of highpressure hoses is not recommended as this can force water into the bricks, whilst some chemical cleaners can cause considerable damage. Brickwork can be washed down using water and a bristle brush. Efflorescent build up should be regularly brushed off using a bristle brush.

Find out how to identify and repair deteriorating render...

Further reading:

• Make the Most of Your Brickwork
• A Guide to External Appearances
• Repointing Old Brickwork