Spalled Bricks
(Last Updated: 14/08/2024)
16/02/2023
110
4 min read
Key Takeaways
- Spalled bricks will be picked up in your property survey when buying a new house
- The risk ranges from inconsequential to potential building collapse
- Extra care must be taken on heritage properties constructed with lime mortar and properties in areas with high traffic pollution
What effect does spalling have on brickwork?
'Spalling' is when bricks (or stone work) crumble, peel, flake, crack or chip away. If a whole section of the wall's surface area is affected by spalling, it may also be referred to as 'blown' brickwork.
What causes spalled bricks?
The most common cause of spalled bricks is simply water. When water seeps into the porous surface of bricks, cracks in the brick itself or damaged pointing, it can begin to break down the brickwork. When this water freezes, it expands, which can cause sections to break away. Bricks which were made with poor raw materials, or which were fired poorly are more prone to spalling.
Extreme heat and weather can also damage brickwork. It is beneficial to have trees or other shielding structures or objects around a brick property, if its location makes it vulnerable to extreme heat, wind or frost.
Pointing
Watch out for new cement pointing on older brickwork - old brick work used breathable lime mortar, sometimes called 'the lungs of the house' which allows water to leave the building. When cement pointing is used on top of soft lime mortar, the moisture is forced out through the bricks themselves, resulting in spalled bricks.
A similar 'suffocating' effect can happen due to the modern use of masonry sealants, and plastic-based masonry paints. If a coloured finish is desired on any lime-mortar structure, limewash should be used instead.
Traffic pollution
Diesel vehicles emit nitrates that form nitric acid, which corrodes organic materials such as brick and stone. Paint should be used to create a protective barrier, in cities and near main roads. Carbonate binders (including limewash) can actually make the spalling effects of nitric acid worse; if the mortar is lime, use breathable paint rather than plastic based paint or limewash.
Is spalling serious?
Mild spalling may be purely aesthetic, but serious spalling can threaten the structural integrity of the whole building, requiring costly repair work. If there is significant damage to the brickwork, you should get a specialist in to assess the risk as soon as possible. You may need to put temporary acrow props in urgently to prevent collapse.
When should I replace spalling bricks?
If serious spalling is identified in your property survey, your surveyor will look for signs of the cause and recommend the next steps, which may involve getting a specialist contractor in to assess the extent of the damage and prepare a quote for replacing the spalling bricks.
If you have spalled bricks on a property you already own, you might be able to hire a contractor straight in to replace the brickwork. However, if the spalled bricks compromise a structural or load bearing wall, then it would be advisable to have a structural engineer survey the damage first.
If spalled bricks are discovered in a property you are buying, your surveyor and solicitor will be able to help you negotiate with the seller, for them to carry out any necessary remediation work themselves, or to reduce their selling price accordingly.
How do you repair spalling bricks?
Generally, repair will mean replacing the damaged bricks altogether, which may mean major structural work. If the spalling is caused by penetrating or standing water, then further building work may be required to remedy the underlying problem.
How much does it cost to repair spalling bricks?
This depends entirely on the extent of the damage. If it's just a small section it should cost less that £1000, but replacing whole walls can cost tens of thousands. If the underlying cause is a bigger problem regarding drainage on the property or a leaky roof, this can inflate the price drastically. For this reason and countless other potential defects, it is essential that you have any property you are buying properly surveyed.
Frequently Asked Questions
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Written by:
Caragh Bailey
Caragh is an excellent writer and copy editor of books, news articles and editorials. She has written extensively for SAM for a variety of conveyancing, survey, property law and mortgage-related articles.
Reviewed by:
Andrew Boast
Andrew started his career in 2000 working within conveyancing solicitor firms and grew hands-on knowledge of a wide variety of conveyancing challenges and solutions. After helping in excess of 50,000 clients in his career, he uses all this experience within his article writing for SAM, mainstream media and his self published book How to Buy a House Without Killing Anyone.
