I had planned to write another blog post today. However, in the last 24 hours the same issue has come up twice, and every time I see it, I despair at the people involved. So the normal schedule will wait, I need to get this one off my chest.
In a lot of parts of the UK, especially in this area, we have a huge amount of ageing housing stock. A lot of properties date from a similar period, which means they will all be seeing the same kinds of issues all at once. It also means that as a building surveyor, I have a pretty good idea of what those issues might be before I even set eyes on the property. In this post, I’ll be talking about properties built around the turn of the century (1880 – 1910), and one of the most common issues.
One of the common features of properties built around 1900 is that they are joined together. It’s why we have so many either semi-detached or terraced houses. This is also why shared chimneys were often built on the party wall line, and also the party walls (or firewalls), continue above the roofline to form what’s known as a parapet wall.
Because of their location, chimneys and parapet walls always bear the brunt of the worst British weather. Exposure to storms can lead to the flashings failing or damage to the render and mortar. When the mortar fails, the brickwork starts to act like a sponge, allowing water to seep into the structure and cause internal damage.
Back in the good old days, before health and safety required safe access at height, this wasn’t such an issue to fix. Your friendly local builder would be more than happy to shimmy up his ladder to perch on your rooftop without a second thought. He’d probably even eat his lunch up there.
But today, it’s not so simple, and these strictures can be very expensive to maintain, largely thanks to the cost of scaffolding. Which means when it comes to maintenance, these chimneys and parapet walls are often neglected on cost grounds, or filed under ‘out of sight, out of mind’.
In order to be truly watertight, chimneys and parapet walls need to be in good repair – on both sides. Even though these normally fall across a boundary line, both sides need to be in good repair.
Here’s an analogy for you. Consider a sponge. If you get one side of the sponge wet, what would happen? Eventually the water would soak through the centre of the sponge and start appearing on the other side. Despite what some tradesmen I’ve seen might think! If you want to keep the sponge dry, then it needs to be kept dry from all sides. Otherwise, the water will just track across and saturate the whole sponge. The same principle applies to chimneys and parapet walls.
Twice in the last day when writing this, I’ve spoken to homeowners who’ve had repairs done to their chimneys or parapet walls, and their tradesmen have just repaired the side belonging to them.
Now, I don’t know who needs to hear this, but water doesn’t really care about ownership or boundaries. So, if there’s a way to get into and track across masonry structures, it will. Even if the other half of the masonry structure isn’t yours. That’s why it’s so important to repair the whole structure, and not just one side.
I wish I had a better response to this one, but the truth is that often only half of a roof repair is done, all because the neighbour doesn’t want to pay for the work to be done on their side.
In an ideal world, this wouldn’t be an issue. All neighbours would get along beautifully, and would be happy to work together to properly maintain the shared part of their property, and their most important asset. But sadly, we don’t live in that perfect world, and some neighbours are unwilling (or unable) to pay for the repairs. Especially in a cost-of-living crisis.
In theory, you might be able to rely on the Party Wall etc Act 1996 to force your neighbour to cough up some cash, but in reality, it can be expensive to administer, which means there’s sometimes little to no cost benefit in pursuing this route. It’s an available option though, and one you should discuss with your surveyor.
Roof leaks can be a tricky thing to deal with, especially because each situation is different. So if you aren’t 100% sure that the repair being recommended to you is right, then you should consult a chartered building surveyor. They will be able to give you advice on how best to repair chimneys and parapet walls, and whether there is a way to require your neighbour to share the cost of works if they’re unwilling to.
If you do commission a tradesperson to complete repairs on a chimney or party wall, then you need to make sure that they’re addressing all the disrepair, and not just hoping that this is the one time in human history that water will care about the boundary lines.
If you’re still a bit confused and you need some advice on the right repair option for your property, whether it’s repairing your chimney, damp–proofing the walls or stopping that scary crack from getting any bigger, then we are here to help. Our expert team of chartered building surveyors are on hand to help you with any query you may have. You can contact Harrison Clarke chartered surveyors on 023 8155 0051, and we will happily help with you with weatherproofing woes.
We also have a range of videos talking through various aspects of Surveying. You can access them via our website or our YouTube channel.
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Tim set up Harrison Clarke Chartered Surveyors in July 2017 following a series of public and private sector surveying roles, having previously worked for the University of Cambridge, Rund Partnership, Goadsby, and CBRE.
Tim has degrees in building surveying, construction project management, and business administration.
