Aberdeen · Scotland
Blackdog External Mastic
We cover Blackdog for sealing brickwork movement joints, render, cladding and façade joints. Old sealant removed completely, joints prepared properly and a one-year guarantee.
- Failed sealant between panels on a façade
- Sealant pulling away from one side of the joint
- Moss and dirt in joints with no sealant left
External mastic in Blackdog, done properly
Many failed façade joints only get noticed once there’s a stain or a damp patch inside. We look over the joints, agree the ones to renew and reseal with a flexible, weatherproof product in a matching colour. If you’re dealing with rain getting behind render or cladding at a joint and plants rooting in failed movement joints, we can help, whatever the surface.
Stone walls need a stone-friendly sealant, as acetoxy products can attack some stone. On newer homes, the movement joints and roofline trims are what need watching.
Big or small, you get the same one-year guarantee in Blackdog and across Aberdeen.
- Where
- Blackdog (AB23)
- Wider area
- Aberdeen
- Guarantee
- A year, on every job
- Price
- A clear price before work begins
- info@mrmastic.co.uk
- Last updated
- 26 October 2026
Looking after it afterwards
Aftercare is simple:
- Keep soil, plants and ivy away from the joints
- Wash walls gently around the sealant
- Fix overflowing gutters above sealed joints
- Walk round the building once a year and look at the joints
Only paint over the joint if we’ve confirmed the sealant can take paint. Paint can crack on a flexible joint and spoil the finish.
Gaps, plants or missing sealant in a joint are worth getting looked at. Early work is quicker and leaves a better finish.
Different surfaces, different methods
Concrete and blockwork
Concrete and block walls shrink as they dry and move with temperature. We reseal their joints with backing rod and a flexible product.
Render joints
Rendered walls have joints at beads, openings and changes of material. They’re resealed in a sealant that suits the render.
Blackdog questions
Is Blackdog within the area you cover?
Yes, we do. We work across all of Scotland, and smaller places are part of that. The journey is planned ahead, so it helps to know about access.
Does living near the coast affect external mastic in Blackdog?
Coastal weather is harder on outside sealant: there’s more wind-driven rain and, closer to the shore, salt in the air. The right product, a clean joint and the right depth all help it cope.
Do you work at height?
Each building is different. Tell us the height, the number of joints and what’s below them, and we’ll confirm what access is needed.
What is backing rod for?
We fit closed-cell backing rod wherever the joint depth needs controlling. It controls the depth and stops the sealant bonding to the back.
Can you seal over the old sealant?
No. The old sealant always comes out first.
Can you work on commercial sites?
Yes. Commercial and hotel work is a large part of what we do. Working times can be discussed when we quote.
How long should I leave it?
That depends on the sealant used, so please follow the time we give you.
Will it make a mess?
Tidy work is part of the job. Nearby surfaces are protected, and the area is left clean when we finish.
Work for landlords, hotels and businesses
Housing providers, facilities teams and property managers book us too. We can quote a run of properties together, and we are fully insured for the work.
In hotels, rooms out of use cost money, so the work can be planned room by room. We’ve worked in hotels as well as homes and businesses.
Outside joints around Blackdog
Blackdog is close to the coast, where wind-driven rain is a fact of life and, nearer the shore, so is salt air. That is hard on movement joints and outside wall joints, especially on the side facing the sea. Under the Repairing Standard, private landlords in Scotland have to keep homes wind and watertight, and failed outside joints work against that.
Historic houses such as Provost Skene's House, about 5 miles south, show how far back building around Blackdog goes, and older homes nearby need a sealant that suits their walls.
Blackdog is about 5 miles north-east of Aberdeen, in Aberdeen. Our applicators cover external mastic for homes and businesses in Blackdog. Blackdog is one of 63 places in Aberdeen where we work for external mastic.
Postcode districts we cover here for external mastic: AB23. You’ll find streets such as Primrose Crescent, Daisy Road and Hareburn Terrace. Other places close to Blackdog include Potterton (1 mile north-west), Balmedie (2 miles north), Belhelvie (2 miles north), Hill of Keir (3 miles north) and Corsehill (3 miles west). Further out, we also cover Aberdeen (5 miles south-west), Rosemount (5 miles south), Berryden (5 miles south-west), Ferryhill (6 miles south), New Aberdeen (5 miles south) and Dyce (5 miles west).
What’s near Blackdog
The nearest railway station is Dyce station, about 4.8 miles west of the centre. A little further out are Bishop Dunbar's Hospital (3.6 miles south) and King's Museum (3.8 miles south). For a walk, there’s Perwinnes Hill and Corby Loch.
Also near Blackdog
More services for Blackdog
Why act early in Blackdog
A failed movement joint lets water into the wall, behind render and cladding. Dealing with it early keeps the repair to the joint, rather than the wall around it. Exposed walls in smaller Scottish places take a lot of wind and rain, and once water gets behind a failed joint, damp in stone or harled walls is slow to dry out.
Instead of a standard rate, we look at what your job involves: the amount of work, the old material and the access. The price is agreed before we begin.
Why choose Mr Mastic in Blackdog
- Anti-fungal silicone where joints get wet
- Neat joints and a tidy finish
- We agree the colour with you first
- White, clear, grey or another colour, product permitting
Common problems we fix in Blackdog
A lot of failed joints come down to preparation: joint faces that were dusty or damp, unprimed where they needed it, or still carrying old sealant. The new sealant then lets go long before it should.
These are the problems we’re asked about most:
- Weathered mastic that no longer stretches
- Leaking joints around cladding and façade panels
- Joints where the bead has come unstuck
- Rain getting behind render or cladding at a joint
Letting a property close to Dyce station? Then failed wall and movement joints let damp in, so they’re worth checking between tenancies.
Questions to ask before you book
- How the surfaces are prepared before sealing
- Whether VAT is included
- Whether all the old sealant comes out first
- How long to leave it before use
How the visit works
We keep the work tidy and contained to the area we are working on. Expect the work to take a few hours to a few days, depending on the length of joint and the access, and we explain the cure time before we leave. Outdoor work around Blackdog depends on the weather, as sealant needs a dry surface, so an outdoor job can move if the forecast changes. Indoor work goes ahead whatever the weather.
- We start by walking round the building and agreeing the joints and the access.
- Every bit of old sealant and any mortar or debris is cut out.
- Joint faces are cleaned back and primed if the sealant needs it.
- We fit closed-cell backing rod to control the depth.
- The exterior sealant is applied, tooled and checked along its length.
Before we arrive
- Clear items away from the joints we’re working on
- Tell us if parking is tricky
- Keep children and pets away from the work area
Getting a quote
If you are in Blackdog and need external mastic, drop us a line at info@mrmastic.co.uk. Tell us what the problem is and where, and you will get a clear quote before any work starts.
Related advice
What affects the cost of external mastic
Jobs vary more than people expect. The main factors:
- How many rooms, windows or areas are involved
- The size of the job
- The product the joint needs
- Any mould that needs treating
What it costs depends on the size of the job, how much old material has to come out and how easy the joints are to reach. We give a clear quote before we start.
Asking for a quote
When you call or email, it’s useful to know:
- How we’d reach the joints
- Whether it has been sealed before
- A few pictures by email, if you can
- The type of property
To get a quote, drop us a line at info@mrmastic.co.uk and tell us where the job is and what the problem looks like. You’ll have a clear quote before any work starts.