Can You Damp Proof Stone Walls?
26 August 2022
An inescapable fact about the UK is that it’s an old country, and there are plenty of old properties people call home to go along with the history.
So, a common question people ask is ‘can stone walls be damp proofed?’ It’s a good question, and one that demands a little more special attention – especially if your home is listed, or if you are worried about using modern damp proofing methods in an older property.
Hopefully this article gives you some ideas on how you can best stop damp from setting in if you have stone walls.
Why Do Stone Walls Get Damp?
Stone walls are just like any other you might find, and the reasons that they become damp are the same that other walls do.
The first reason that a stone wall might become damp is due to a process known as rising damp. Rising damp occurs when moisture makes its way from the ground below a property up into its walls through a process known as capillary action.
Capillary action usually allows moisture to make its way into walls once the damp proof course (DPC) has failed.
The damp proof course exists for one reason: to stop rising damp from travelling upwards, into your walls and damaging them. The DPC is a thin layer of chemicals injected into your wall which moisture cannot pass through. This is why rising damp is often located in just one spot in a property, rather than slowly making its way upwards all round a buildings walls at once: because the DPC has failed in one spot, and that’s where the damp is making its way through.
It’s easy to spot rising damp. Usually the dampness in the wall will be restricted to travelling about one meter off of the ground, and that same dampness in your wall might extend itself to your floorboards, skirting, or joists, warping the floor or other timber in your property.
If left alone and untreated rising damp can easily spread and have horrible affects. As we just mentioned, you need to be on the lookout for your wood warping if damp is present, and that’s only the start. Your wood could also develop a condition known as dry rot, which involves a horrible orange fungus growing on your timber and rapidly spreading.
Dry rot isn’t the only fungus to look out for either, as black mould also loves damp walls, so if you do decide to leave your rising damp untreated you might find that your walls become ‘blotchy’ with the fungus that black mould grows.
Penetrating damp is a form of damp that occurs when there is a fault within the actual property itself. Here we are talking specifically about stone walls, so if your properties stone walls aren’t pointed correctly, if they have cracks or faults, or if there is something continuously leaking onto your walls then you might well start to see damp setting in.
In these situations, the damp can present itself anywhere. You might notice that the stone on the exterior of your property becomes darker, as if it were damp, and you could notice that the wall itself isn’t retaining heat as it usually might do.
On the interior of your property you might notice that whatever you have on top of the stone walls is appearing damp. Wallpaper might peel off of the wall, plasterboard could be wet to the touch, and through it all, the distinctive dark patches that indicate damp is present might be easily seen.
Just like rising damp, penetrating damp can spread. Once moisture is within a stone wall, it can easily damage its surrounding area and spread out. This doesn’t just apply to within the wall itself either – you might find that the damp in your walls spreading and into any connected timber, including ceiling beams or windowsills.
Obviously this is going to have nasty consequences, just like rising damp, so its best to not ignore rising damp in your property and have it seen to by a professional immediately.
Condensation is the last reason that your stone walls might develop damp.
It’s a cause that is entirely down to the behavioural habits and lifestyles of those within the property. Actions like showering, cooking, washing, even exercising, are all examples of routines that can cause condensation to build up.
Condensation is nothing more than the gaseous moisture within warm air turning into a liquid again when it comes into contact with a cold surface or area.
So, if you have (for example) a bathroom with exterior facing stone walls, you might notice that during a shower in a colder time of the year it gets misty fast. All of that mist is going to come into contact with those cool stone walls as the warmer air gets pulled outside thanks to the difference in air pressure.
On contact with the walls the same air is going to turn into condensation. Over time, and if left untreated with no change in the daily routine, you will find that the condensation can turn itself into a lasting damp problem.
Just like other forms of damp, this can quickly turn very problematic. Black mould and other fungi love these moist patches and can quickly set in if the root cause of the condensation isn’t fixed.
Damp Proofing Your Stone Walls
Damp proofing the stone walls in your property is a much needed task if you want to keep the property in a healthy, working order.
If you have already noticed that your property has a damp problem, then you need to arrange a survey with a trained an experienced professional. Our team, for example, will be able to visit your property in person and not only diagnose the type of damp in the property (and the extent of the damage), but also identify what steps should be taken to make sure that the damp is removed once and for all, and that your property stays in healthy condition.
Treating Rising Damp in a Property with Stone Walls
Stone walls are no different to brick or other materials in that the best way to stop rising damp is with the installation of a damp proof course.
A damp proof course is the only way to be certain that no more moisture will be making its way into your properties stone walls.
Here at Timberwise, our team can install a DPC through a chemical injection process. All that’s needed is one of our technicians to visit your property, where they will drill a small hole into your properties external walls near the ground.
Once that’s done, our technician will inject a chemical foam into the wall, which acts as a DPC. Its that easy, and once in the wall the DPC will stop any further moisture rising into the wall itself. Any rising damp in your wall will then dry out, and you can begin repairs on your property without the worry that anything you do will just be ruined again by the rising damp.
There is another option when it comes to rising damp in a stone wall; an electro-osmotic system. Similar to a DPC, an electro-osmotic system sits towards the bottom of your stone wall, and (through a small voltage) dissuade capillary action from taking place due to the build up of titanium dioxide within your wall.
You can read more about the whole process here, but its well suited to stone walls, especially walls made of stone, where a chemical course might not be as affective as a solid ring of constant electricity.
Treating Penetrating Damp in a Property with Stone Walls
Penetrating damp, unlike rising damp, is a little more tricky.
The first step in having penetrating damp treated is having a damp survey carried out. A properly trained and Property Care Association (PCA) accredited surveyor will be able to help you identify the root cause of the penetrating damp in your stone walls, and suggest what work should be carried out in order to put a stop to it.
In many cases our team will be able to carry out that work themselves. Different jobs like window lintel repair, crack stitching, or even pointing are within our wheelhouse, and can be taken on by our technicians.
In some situations though, the penetrating damp in your stone walls might have been caused by something else entirely, like a leaky roof, or a broken drainage system. In these situations your survey report will outline the best way for the penetrating damp to be stopped, and what kind of services you might need to employ to make that happen.
Once the cause of the penetrating damp has been routed out and fixed though, your stone walls will dry out, and it will be completely safe to repair any damage that has happened to them on the exterior or interior.
This means you can redecorate the inside of your property, and make whatever amends you need to the exterior. This might mean you need a specialist who can work with different, specific types of stone – but you can rest assured that these fixes will be long term as the initial damp that caused the damage has been stopped.
You could also look into the potential of having a Type A Waterproofing solution, or tanking, applied to your walls. Especially in stone walls composed of smaller rocks, a tanking solution is an effective way to stop any potential damp entering your property from physically leaking through into the interior of your property.
Once applied, you will be able to decorate your walls just as you would have without the tanking ,but now with the added bonus of the risk of water ingress and flooding being minimised. You can read more about our tanking services here.
Treating Condensation based Damp in a Property with Stone Walls
As mentioned before, condensation is nearly always a product of the people that reside or use a property, as the actual moisture in the air is a product of activities, rather than something that builds up passively.
You could always start the process of eliminating condensation by examining your day to day habits, and identifying things you do in a day that generate steam. Cooking, showering, even physical activity; all ways in which condensation can build up in a property.
Then you need to look into ventilation options. The easiest, and most effective way of eliminating condensation is by allowing any steam generated in your home to ventilate out of the property cleanly.
Obviously, if you have thick stone walls ventilation could be a problem. A start would be opening up windows and doors, and possibly even looking into extractor fan options to make sure that you have ventilation options open to you.
Of course, if these solutions aren’t enough to combat the condensation settling on the stone walls in your property, you can always have our team conduct a condensation survey for you. By examining your property as well as your daily habits, a Timberwise surveyor can easily identify what is causing the mist to build up in your property, and what steps should be taken to stop it.
This can include the installation of one of our positive pressure systems, a ventilation unit that constantly pulls fresh air from outside the property inwards, pushing it through the interior of the building so that any stagnant or moist, dense air is pushed out by the new cooler air.
All of this begins with a call to our team though.
If you have noticed that your properties stone walls could use some help to get rid of damp, black mould, or another problem that you aren’t too sure about, our team can help. Call 0800 288 8660, or get in touch online here and we will help restore your stone walls to full health.