What is brickwork spalling and is it a serious issue?

If you see brickwork crumbling away on your house or garden wall, it’s normal to be concerned. At Collier Stevens, we’re here to guide you when it comes to identifying what the problem is, why it occurs, and what can be done about it.

What is brickwork spalling?

Brickwork spalling is the gradual disintegration of the face of bricks. It looks like the brickwork is flaking, chipping or crumbling from the front-facing part, revealing the softer inner part of the brick.

What causes brickwork spalling?

Brickwork spalling is caused by water getting inside the brickwork. Not all bricks are the same – some are harder and some are softer. That means that when they get wet, the water evaporates from them at different rates.

Brick deterioration is most common in older properties. This is usually due to the pointing having been replaced with sand and cement. The original lime-based pointing allowed moisture within the brickwork to evaporate through the brick joints. Replacement with sand and cement does not allow the water to evaporate through the pointing, so the water evaporates via the brickwork instead, slowly forcing the face of the brick away. Poor pointing can also allow moisture into a brick wall, which can contribute to brick deterioration and internal dampness.

The freeze-thaw cycle, where the water expands when it freezes, also impacts on bricks. When this moisture in the brickwork goes through this cycle, it causes movement within the bricks. The brickwork weakens as the ice melts, resulting in cracks appearing and the mortar crumbling. The face of the brick will be pushed away, causing spalling and visible cracks to appear.

Road salt can also cause similar deterioration, which is why you can often see deteriorated brickwork at low level on walls that are close to a pavement or roadway.

Finally, pollution can cause brickwork spalling, particularly in built up high traffic areas. It isn’t as problematic now, but the brickwork on older houses will have been exposed to this for many years.

What are the white marks on my brickwork?

As water evaporates from brickwork, it can draw to the surface salts from within the brickwork and the pointing. These salts leave behind a white bloom known as a fluorescence. Generally this does not cause any particular damage to the brickwork but it is unattractive and cosmetically poor, as the images below show:

Are spalling bricks dangerous?

No- brickwork spalling is not dangerous. There can be health risks, however, if the bricks have absorbed so much moisture that the property has damp and mould.

What problems can brickwork spalling cause?

As the bricks continue to deteriorate, their ability to limit the risk of internal dampness developing also lessens, meaning the risk of damp inside is greater. Replacement of the bricks is recommended to avoid this. In addition, as more moisture is allowed into the brickwork, it causes further movement and more cracks to appear. Left untreated, it will affect the structural integrity of a building or boundary wall.

A single defect survey will help to identify if spalling has occurred and what its implications may be. Our building surveyors in Kent will also advise you on how to resolve the problem, and also how to prevent it from getting worse.

Does brickwork spalling brickwork affect the structure of my house?

Yes, but only if it is left untreated. It’s important you have a professional surveyor assess the damage to help you understand how it can be fixed. If you are buying a stone or brick built house that was constructed before the 1980s, you are more likely to experience spalling. We always recommend that people invest in a full building survey or a RICS level 3 survey, so that you can receive a report identifying any spalling and what can be done about it.

Can I repair spalling bricks?

Yes, although prevention is always better than cure. We would always recommend using a professional builder rather than taking the DIY option. It’s not simply a case of using a bit of filler.

How easy is it to repair spalling brickwork?

Whilst it isn’t easy, it can be done.

Sometimes this can be done by cutting away the face of the brick and applying a brick slip, a slim brick face that can be adhered to the front of the damaged brick, covering any damage. This is more suitable if there are only one or two damaged bricks. The mason will chisel the stone away to the right depth to allow the brick slip to sit evenly with the rest of the brickwork.

Sometimes the spalling can be repaired by applying the brick face with coloured render, although the best approach is to replace the whole brick. Repairing the damaged brick with a skim of render is seldom satisfactory. That’s because eventually moisture gets behind the render and forces it away from the brickwork, presenting a further risk.

Finally, any brick repair will only be as good as the pointing repairs around it. Our advice would be to consider replacing a modern sand and cement render with a more traditional lime based mortar if there is a regular and ongoing problem.

Can I replace crumbling bricks?

Depending on the damage, it can be costly to repair or replace spalling bricks. Bricks are removed and then replaced with new and matching bricks – according to Checkatrade, this can be from £12 to £26 per brick. This is another reason to have a building survey completed when you’re buying a property.

Can I prevent brickwork spalling?

At some point, all stone or brickwork properties will suffer spalling. However, if a house is built well and the bricks or stone are of a high quality, the process of spalling will be slower.

Older houses are more prone to spalling as the bricks become more porous with age, but remember if a new building has reclaimed bricks, these will spall faster than new, high quality ones.

Spalling can be slowed down a number of ways:

• Repair any bricks that are damaged.

• Paint walls with a breathable masonry sealant, especially if you live in coastal, or exposed locations – particularly new walls, or walls that have been repaired. You can seal spalling bricks to slow down the process, but you should repair the brick first.

• If you have damages pointing, make sure you have repointing done to prevent further water ingress.

• On busy roadside properties, use trellis and non invasive plants to protect bricks from traffic pollution

• Prune any climbing plants to reinforce brickwork

• Ensure drains are clear to prevent floods or leaks.

Can surveyors spot early signs of brickwork spalling?

Yes. Our chartered surveyors in Kent, we undergo intense training to ensure we adhere to high standards. We are highly qualified to look for all kinds of defects on properties. The key early signs of spalling, or evidence the risk of it occurring is high, are:

• Florescence

• Crumbling pointing

• Cracked walls

A Level 2 Homebuyer Survey is an intermediate report for newer properties, and from this we will advise a homebuyer if there are spalling bricks. A Level 3 survey is more appropriate for older properties, as they include a detailed description of the spalling, what work might be needed to repair it, and that the cost of that might be,

Get in touch for brickwork spalling support with Collier Stevens

At Collier Stevens, we are here to offer expert advice on the condition of your property. Get in touch to see how we can help.

About the Author

Steven Way

Steven Way BSc MIHEEM MFPWS MRICS is the Practice Principal and is a Chartered Building Surveyor. With over 35 years as a practicing surveyor, Steve has a wealth of experience and expertise in both residential and commercial building surveying, party wall advice and disabled access auditing. He has also built his reputation as an expert witness.