Glasgow · Scotland
Thornliebank External Mastic
External mastic in Thornliebank from a team with over 20 years’ experience. 180+ five-star Google reviews and a 4.9 rating.
- Failed seals between different materials
- Hard, crazed mastic that has stopped moving
- Joints where the bead has come unstuck
How the job changes by surface
Copings and trims
Copings expand and contract through the day, so the joints need a sealant that stays flexible in all weathers.
Cladding and façade panels
Cladding and façade panels are generally separated by sealed joints. We reseal them with a sealant suited to the panel material.
External mastic in Thornliebank
We cut out failed sealant, set the joint depth with closed-cell backing rod and reseal with a low-modulus exterior sealant. The colour is chosen to suit the brick or render. If you’re dealing with water getting into walls through failed joints and rigid filler in a joint that should flex, we can put it right, on façade panels, copings & trims and concrete & block alike.
Gutters and downpipes on tall city tenements are a long way up, so a leaking joint can run down the stone for months before anyone notices. For a building in Thornliebank, access is planned first, and shared parts may need the other owners to agree.
Our work is backed for twelve months, and the guarantee is the same wherever you are.
- Where
- Thornliebank (G46, G77)
- Wider area
- Glasgow
- Cover
- 12 months on all our work
- Quote
- A clear quote up front
- info@mrmastic.co.uk
- Updated
- 26 October 2026
Should I try it myself first?
Too much sealant is as bad as too little. A thick, smeared bead looks untidy and doesn’t move well, and the joint depth matters as much as the finish.
If you do try it yourself, take your time over the preparation: take out all the old sealant, make sure the joint is clean and dry, and give it the full cure time. If it doesn’t work out, we can still put it right.
What we can’t put right
Sealant isn’t the answer to every problem, and we’d rather say so up front. Sealant won’t put right:
- Rising or penetrating damp from elsewhere in the wall
- Failed render or damaged cladding panels
- Structural movement, which needs a surveyor or engineer
If you are not sure, just send an email to info@mrmastic.co.uk and we will give you a straight answer before you book.
Surfaces we seal
- Copings & trims
- Joints between brick and frames
- Render & cladding joints
- Concrete & block
- Brickwork movement joints
- Façade panels
What happens on the day
All our tools and materials come with us in the van, so you do not need to buy or prepare anything. Once we’ve agreed what’s being done, we protect the area and start. It normally takes anything from a few hours to several days, depending on the building. Many homes in Scotland’s cities are tenement flats, reached through a shared close and up a common stair. In Thornliebank, it helps to know the floor, the door entry arrangements and the nearest parking.
- We look at every joint and agree a colour to suit the wall.
- Failed sealant is removed back to clean, sound faces.
- Closed-cell backing rod is pushed in so the sealant bonds to two sides only.
- Primer is applied wherever the sealant needs it.
- A low-modulus exterior sealant is gunned in and tooled to a neat finish.
Before we arrive
- Keep pets and children clear of the area while we work
- Let us know if you’ve seen damp or leaks
- Let us know about parking restrictions
Get a quote
We quote each job on its own, so start by telling us what you need. Just email us at info@mrmastic.co.uk with the details.
Related advice
Common questions in Thornliebank
Can you do external mastic in Thornliebank?
Yes. We work across all of Scotland, and Thornliebank is part of that. Just email us at info@mrmastic.co.uk with a few details of the job.
Who arranges sealant work on the shared parts of a tenement in Thornliebank?
It normally goes through the owners together, or through the factor if the building has one. The Tenements (Scotland) Act 2004 covers the common parts where the deeds do not, and we can quote for the factor or the owners directly.
Can I add another job to the visit?
Yes. Just list everything you need.
Is there any odour?
Possibly a little. It fades as the sealant cures, and ventilation helps.
I’m a tenant. Can you help?
We can work for tenants, landlords or agents. Get your landlord’s agreement first.
Is it worth trying it myself?
Sometimes. Preparation is everything: all the old sealant out, and a clean, dry joint. If it does not work out, we can redo it.
Will the old sealant be removed?
Yes. We cut out all the old sealant and clean the joint before resealing.
What sealant do you use?
The product depends on the job: anti-fungal sanitary silicone in wet areas, and other sealants where joints move or face the weather. Brands we use include Arbo and Everbuild.
Aftercare tips
So the new joints stay in good condition:
- Act on the first splits you see
- Point out the joints to other trades
- Walk round the building once a year and look at the joints
- Check the sealant is paintable before painting near it
Do not let soil, plants or ivy build up against the new joints. Damp material against the sealant shortens its life.
Small splits are the time to act. Then it’s a straightforward cut-out and reseal.
Why deal with it now?
Water gets in through a failed movement joint, behind render and cladding. Dealing with it early keeps the repair to the joint, instead of the wall and finishes around it. In a tenement flat in Thornliebank, a failed seal is rarely just your problem: a leak can come through the ceiling below, and gaps in shared walls or fire-rated joints matter to every flat.
The cost reflects the work involved, not a rough estimate. That is why we ask about the job first.
Why Thornliebank clients choose us
- Sanitary silicone with an anti-fungal additive in wet areas
- A 12-month guarantee on all work
- Fully insured
- Any old sealant cut out fully, not covered over
See our cost guide and what customers say.
External mastic in Thornliebank: local notes
Plenty of Scottish homes have harled walls, and where harling meets frames, pipes and other materials, the joint needs a flexible sealant that grips a rough surface. Much of Glasgow is built from red and blond sandstone, and porous sandstone needs a sealant that will not mark it.
Letting a property close to Whitecraigs station? Then outside joints that have cracked can let damp into a rental, so check them between lets. If you look after a building such as Eastwood High School, its movement joints, gutters and trims need looking after like any other building’s. Pollok House, about 1.9 miles north, is one of the historic houses in the wider area around Thornliebank.
Thornliebank is about 1 mile west of Giffnock, in Glasgow. For external mastic in and around Thornliebank, please email us at info@mrmastic.co.uk for a quick quote. We cover Glasgow from our Crawley base. Thornliebank is one of 183 towns and villages in Glasgow we cover.
Every address in G46 and G77 is covered for external mastic, from the main roads to the quietest streets. Streets in the area include Skibo Lane, Main Street and Arden Avenue, and we cover them all. We also cover Carnwadric (1 mile north-west), Arden (1 mile north-west), Kennishead (1 mile north), Eastwood (1 mile north) and Southpark Village (1 mile west). Further out, we also cover Glasgow (4 miles north-east), Hillhead (5 miles north), Dowanhill (5 miles north), Woodlands (5 miles north), Woodside (5 miles north) and North Kelvinside (6 miles north).
Around Thornliebank
Around Thornliebank, our work takes us to homes and buildings near Rouken Glen and Belmont House School. The nearest railway station is Whitecraigs station, roughly 0.7 miles south. Nearby you will also find Glasgow Victoria Infirmary (2.7 miles north-east) and Silverburn Shopping Centre (1.8 miles north-west). Open spaces near Thornliebank include Cathkin Braes and Brother Loch.
What affects the cost of external mastic
Every job gets its own quote. These are the things that affect it:
- Any working-time requirements on site
- The number of rooms or windows
- Whether the work is at height
- How much old sealant there is and how hard it is to remove
Commercial jobs are quoted on the same basis as homes: the amount of work, how we reach it and what it needs, plus any working-time requirements on site. Ask us for a quote and we will go through it with you.
What to tell us for a quote
The more you tell us, the more accurate the quote. When you ask for a quote, tell us:
- Photos by email, if that’s easy
- The type of property
- The rough size of the job
- The address or postcode of the job
The more we know about the job, the more useful the quote. Let us know the location, the problem and roughly how many joints, and email photos if that’s easy.