Removing paint from stonework requires careful consideration to avoid causing any damage to your building. Whether it’s graffiti that needs to be swiftly dealt with, or a decision to restore the stone’s original appearance, it’s important to take the right approach.
Should we remove paint from stonework?
Graffiti on your building should be addressed promptly to discourage further vandalism. However, it’s crucial to seek guidance from your local council on the proper removal process. Attempting to remove graffiti without the right technique can potentially damage the stone further. Additionally, there are some important factors to consider when removing paint from stonework, whether it’s graffiti or another form of paint.
Stone buildings, particularly older sandstone tenements, are ‘breathable’. This means they naturally insulate and ventilate simultaneously by allowing moisture to be expelled through the porous stone bricks of which they are made. Therefore, removing paint may be necessary for the long-term health of a stone building to ensure its ‘breathability’ is maintained.
However, depending on the type of paint on the stone building and the type of building, there are other considerations to be aware of, such as:
- The stone may have been painted to cover old repairs or as part of the traditional style in your area. Removing paint can alter the appearance, which may not be desirable.
- Paint can act as a barrier, preventing rain from penetrating very porous stone. Removing paint may expose the stone to moisture-related issues.
- If your property is located in a conservation area or is a listed building, removing paint may require planning consent.
- Chemical paint removers can pose health risks, and lead-based paint is classified as hazardous waste.
- Thickly applied historic paints can be exceptionally difficult to remove from porous stone types.
- If your building is harled (rendered), it is important to keep the harling painted. The paint will cover hairline cracks that, if exposed, risk allowing moisture to get behind the harling, causing it to break off.
Paint removal methods
Regardless of the method chosen, it’s important to remember that paint removal will cause some degree of damage to the stone. Therefore, it’s recommended to always conduct a patch test to assess the impact.
When it comes to removing paint from stone, there are a range of methods available. Always start with the least aggressive method and consider contacting a professional for advice on the best method for your building.
The different methods of paint removal, from least to most aggressive are:
- Weathering and natural deterioration – allow nature to take its course and let the paint deteriorate naturally.
- Water washing – use gentle sponging or scrubbing with a soft bristle brush for emulsions, limewash, and very old, friable paints.
- Steam stripping – superheated low-pressure steam can effectively remove water-thinned paints, like emulsions, without saturating the stone’s surface.
- Solvent (non-caustic) chemical removers – consider water-soluble removers before using methylene chloride-based solvents. They work best for removing oil or latex-based paints.
- Alkaline (caustic) chemical removers – caustic soda or potash can be highly damaging to stonework and may be absorbed by porous stone which can lead to ongoing damage. These should be avoided unless no immediate or ongoing damage is visible from a patch test. If using a chemical remover, it should be thoroughly washed from the stone to avoid leaving any residue.
- Manual abrasive – aggressive manual cleaning methods like scraping, sanding, or wire bristle brushing can cause significant damage to the stone.
- Mechanical abrasive – high-pressure water cleaning, sand, or grit-blasting can also result in significant damage to stonework, making it more vulnerable to weathering. It can also result in the loss of architectural detail.
It’s important to remember that for particularly stubborn paint, allowing it to weather naturally might be the best course of action to avoid further damage.
While paint removal might seem straightforward, it’s essential to ensure that your builder or tradespeople have the necessary skills for the job. When in doubt, seek professional help to specify and organise paint removal.
Who pays for paint removal?
Paint removal falls under the category of maintenance and common repairs, making it the responsibility of all owners in a tenement building.
As always, check your title deeds to confirm who is responsible for paint removal repairs to your building. If your title deeds don’t say anything on the matter or are unworkable, you should refer to the rules in the Tenements (Scotland) Act 2004.
For more information on common repairs and tenement maintenance, check this article.
