Aberdeenshire · Scotland
External Mastic in Potarch
Problem with your movement joints in Potarch? We cut out the old, prepare the joints and apply the right sealant, and the work is guaranteed for a year.
- Damp patches traced to an open external joint
- Movement joints filled with mortar instead of sealant
- Weeds or debris growing in open joints
External mastic for homes and businesses in Potarch
Movement joints let brickwork, render and cladding expand and shrink without cracking. The sealant in it has to stretch and squeeze for years, so once it splits or hardens, the joint stops working and water gets in. If you have old sealant gone brittle and cracked and rigid filler in a joint that should flex, we can put it right, whatever the surface.
External sealant needs dry surfaces, so outdoor work around Potarch is planned around the weather. Let us know about access to every wall and roofline.
There’s a 12-month guarantee on every job, whatever its size.
- Place
- Potarch (AB31, AB34)
- Wider area
- Aberdeenshire
- Cover
- A year, on every job
- Quote
- A clear quote up front
- info@mrmastic.co.uk
- Page updated
- 26 October 2026
DIY sealant or a professional job?
Sealing over old silicone is the commonest DIY error. New silicone won’t bond to old, so it peels away and traps moisture behind it. All the old material has to come out first.
Not every job suits DIY: work at height, external movement joints, fire-rated sealant and large areas call for the right materials, safe access and experience.
How it works
At the end, we look at the finished work together and explain the cure time. The work normally takes a few hours to a few days, depending on the length of joint and the access, depending on how much there is to do. Around Potarch, distance and access matter more than parking. Tell us how to find the property and how to reach the work, and the visit is planned around that.
- We start by checking each joint, agreeing the ones to redo and how we’ll reach them.
- We cut out the failed sealant and rake out any dirt or growth.
- The joint faces are cleaned and primed where the sealant needs it.
- Closed-cell backing rod is fitted to set the depth and stop three-sided bonding.
- A flexible exterior sealant is applied and tooled in a colour to suit the wall.
Preparing for the visit
- For indoor joints, keep the area dry beforehand if you can
- Let us know if you’ve seen damp or leaks
- Clear items away from the joints we are working on
Ask for a quote
We quote each job on its own, so the first step is telling us about yours. Just email us at info@mrmastic.co.uk with the details, and photos are welcome.
Related advice
When to call us in Potarch
Sometimes a movement joint was filled with mortar or a rigid filler, often by someone who didn’t know what it was for. With the joint locked solid, the movement turns into cracks elsewhere in the wall.
Most people get in touch when they notice something like this:
- Sealant pulling away from one side of the joint
- Old sealant gone brittle and cracked
- Water getting into walls through failed joints
- Gaps where render, brick and frames meet
Whether the job is in Potarch itself or nearby, the right material for each joint matters as much as a neat finish.
Comparing quotes
- What happens if they find a problem under the old sealant
- When the joint can take water or movement
- The length of the guarantee
- What the quote includes, VAT included or not
What else we do in Potarch
How the job changes by surface
Copings and trims
A failed coping joint lets water into the top of the wall. Resealing them is a small job that protects a lot.
Brickwork movement joints
Brick moves with heat and moisture, and grows a little over time. The movement joint takes that up, so its sealant has to stay flexible.
Why it’s worth doing now in Potarch
Water gets in through a failed movement joint. Dealing with it early keeps the repair to the joint, instead of the wall and finishes around it. Exposed walls in smaller Scottish places take a lot of wind and rain, and damp in stone or harled walls takes a long time to dry once water gets behind a joint.
The cost depends on how much there is to do, how much old material has to come out and how easy the joints are to reach. You will have a clear quote before any work starts.
Why us?
- We’re fully insured
- A choice of colours where the product allows
- Sanitary silicone with an anti-fungal additive in wet areas
- Colour picked to suit the job
See our cost guide and what customers say.
Potarch buildings and the weather
Harled (roughcast) walls are common in Scotland, and where harling meets frames, pipes and other materials, the joint needs a flexible sealant that grips a rough surface. Under the Repairing Standard, private landlords in Scotland have to keep homes wind and watertight, and sound outside sealant is part of that.
Around Potarch, as everywhere, external mastic is only as good as the preparation behind it.
Potarch is about 6 miles west of Banchory, in Aberdeenshire. Across the AB31 area, we can carry out external mastic at your property. Across Aberdeenshire, we cover 161 places, Potarch among them. Aberdeen is on our list too, around 21 miles away.
Our applicators cover all of the AB31 and AB34 postcode area for external mastic. Nearby, we also carry out external mastic in Kincardine O'Neil (2 miles north-west), Torphins (3 miles north), Inchmarlo (4 miles east), Lumphanan (5 miles north) and Birsemore (5 miles west). Within a short drive, we also cover Westhill (15 miles north-east), Banchory (6 miles east), Kemnay (14 miles north-east), Aboyne (5 miles west), Alford (12 miles north) and Ballater (15 miles west).
Landmarks near Potarch
Other landmarks nearby include Kincardine O'Neil Hospital (1.8 miles north-west) and Castlehill of Strachan (4.4 miles south-east). Open spaces near Potarch include Loch of Aboyne and Scolty Hill.
Keeping the joints in good condition
Looking after new joints is easy, and it makes a real difference:
- Make sure movement joints are not pointed over
- Fix overflowing gutters above sealed joints
- Leave the joints unpainted unless we’ve said otherwise
- Act on the first splits you see
Follow the cure time we give you before the joint is knocked or disturbed. Most exterior sealants skin fast but take longer to cure right through.
Once a joint can’t move, the wall finds another way, generally as cracking in the brickwork or render nearby. Catch it early and you reduce the risk.
FAQs for Potarch
Is Potarch within the area you cover?
Yes, we do. Our work covers the whole of Scotland, from towns to the smallest places. Longer journeys are simply planned in advance.
Is there a guarantee on external mastic in Potarch?
All our work, in Potarch and everywhere else, comes with a 12-month guarantee. We are also fully insured and ARBOMaster approved.
Do you use backing rod?
That is backing rod, a closed-cell foam. It keeps the sealant at the right depth and bonded to the sides only.
What sealant do you use?
It depends on the joint: sanitary silicone where it gets wet, and sealants suited to movement or weather elsewhere. We use products from Arbo and Everbuild.
How long does external mastic take?
It depends on the size of the job, but as a guide it takes a few hours to a few days, depending on the length of joint and the access. We’ll give you a better idea when we quote.
Can you match the colour of my brickwork?
The aim is a neat, even joint in a colour that suits the wall. We will talk through colour options before work begins, matched as closely as the range allows.
Are you insured?
Yes. Mr Mastic is fully insured, with over 20 years’ experience in sealant work.
Is it OK to seal over old sealant?
No. Fresh sealant does not stick to old sealant, and it traps any mould or water underneath. It all has to come out first.
When something else is needed
We’ll always be straight with you, so here’s what sealant cannot fix:
- Render that’s blown, hollow or coming away
- Damp from another source, such as a leaking gutter or a bridged damp-proof course
- Structural movement, which needs a surveyor or engineer
If in doubt, email us at info@mrmastic.co.uk and we’ll say what we think.
What we seal
- Façade panels
- Copings & trims
- Brickwork movement joints
- Concrete & block
- Render & cladding joints
- Joints between brick and frames