Renfrewshire · Scotland
Lochwinnoch External Mastic
External mastic for Lochwinnoch and the surrounding area: the right sealant, proper preparation and a neat finish. Call for a quick quote.
- Sealant pulling away from one side of the joint
- Weeds or debris growing in open joints
- Hard, crazed mastic that has stopped moving
External mastic for homes and businesses in Lochwinnoch
Getting the depth right is half the job. Backing rod controls how deep the sealant goes and keeps it off the back of the joint, leaving it bonded to two faces so it can move with the wall. If you have rigid filler in a joint that should flex and cracked joints where brick meets render or frames, we can help, on concrete & block, copings & trims and brickwork movement joints alike.
Outside joints can only be sealed when they’re dry, so work in Lochwinnoch depends on the weather, and longer journeys are planned in advance. Let us know about access to every wall and roofline.
There’s a 12-month guarantee on every job.
- Where
- Lochwinnoch (PA12)
- Region
- Renfrewshire
- Cover
- One year on every job
- Quote
- A clear price before we start
- info@mrmastic.co.uk
- Updated
- 26 October 2026
Lochwinnoch buildings and the weather
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. Private landlords in Scotland must meet the Repairing Standard, which includes keeping a home wind and watertight, and failed outside joints work against that.
For landlords with property near Lochwinnoch station, split movement joints are easy to miss on a rental until damp shows inside.
Lochwinnoch is about 5 miles south-west of Johnstone, in Renfrewshire. We provide external mastic to householders, landlords and businesses in Lochwinnoch and nearby, as part of our work across Renfrewshire. Lochwinnoch is one of 21 towns and villages in Renfrewshire where we work for external mastic. You can also see our page for Glasgow, about 14 miles away.
Here we cover the PA12 postcode area for external mastic. If you need external mastic at a property on High Street, Main Street and Glenpark Road or anywhere close by, we can help. Other places close to Lochwinnoch include Beith (3 miles south), Gateside (3 miles south), Kilbirnie (4 miles south-west), Longbar (4 miles south) and Glengarnock (4 miles south-west). Further out, we also cover Paisley (8 miles east), Renfrew (11 miles north-east), Johnstone (5 miles north-east), Erskine (10 miles north-east), Bishopton (9 miles north-east) and Glenburn (8 miles east).
Local landmarks in Lochwinnoch
The nearest railway station is Lochwinnoch station, about 0.8 miles south-east. Nearby you’ll also find Merchiston Hospital (5.3 miles north-east) and Lochwinnoch Community Museum (under half a mile south). Not far away are Castle Semple Loch and Walls Hill.
Different surfaces, different methods
Joints between dissimilar materials
Brick against render, concrete against metal, stone against timber: every change of material is a joint. We seal the joint with a flexible exterior sealant so the movement is taken up.
Concrete and blockwork
Blockwork and concrete shrink over time and move with the seasons. We reseal their joints with backing rod and a flexible product.
What affects the cost of external mastic
Call for a quick quote. The main things that affect it are:
- Mould in or behind the old joints
- Whether the work is at height
- The type of sealant required
- The old material and how stubborn it is
What you pay reflects the work, not guesswork. That is why we ask about the job first and agree the price before starting.
What we need to know
When you call or email, it’s useful to know:
- If someone has resealed it before
- What’s wrong with the joints now
- Any access issues, like height or stairs
- A few photos by email, if you can
Every job is quoted individually, so the first step is telling us about yours. Just send an email to info@mrmastic.co.uk with the details and send pictures if you have them.
Your questions about external mastic in Lochwinnoch
Can you help a landlord with a rental near Lochwinnoch station?
Yes, rental work is part of what we do. Just drop us a line at info@mrmastic.co.uk and tell us about the property, and we’ll give you a clear price.
Is Lochwinnoch in your area for external mastic?
Yes, Lochwinnoch is within the area we cover. We work across all of Scotland. You can drop us a line at info@mrmastic.co.uk and tell us what needs doing.
Why is there a gap in my brick wall?
Most straight vertical gaps in brickwork are movement joints. It gives the wall room to move.
Are you fully insured?
Yes. We are fully insured.
Where are you based?
We are based in Crawley, and we work across South East England, London and Scotland.
How long does external mastic take?
Typically it takes a few hours to a few days, depending on the length of joint and the access. Bigger jobs take longer, and we’ll say how long yours will take.
Is there a guarantee?
Yes. Every job comes with our 12-month guarantee.
Do you work for hotels and businesses?
Yes, regularly. We can plan bigger jobs in stages to suit the site.
Also near Lochwinnoch
Also in Lochwinnoch
DIY sealant or a professional job?
The biggest DIY mistake is sealing over old sealant. Silicone doesn’t stick to old silicone, so it lifts and traps water and mould underneath. All the old material has to come out first.
A DIY attempt does not rule out a professional job. We cut it out and start again, so tell us about it when you ask for a quote.
The process
Good joint work is mostly preparation, so that’s where we spend the time. Joints are cleaned back and dried before anything new goes in. All told, the work takes anything from a few hours to several days, depending on the building. Outside jobs in Lochwinnoch need a dry day, because sealant won’t bond to a wet joint, so external jobs may need to move if the day turns wet. Work indoors isn’t affected.
- First, the joints are inspected and the access agreed.
- We cut out the old mastic and rake out anything in the joint.
- 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
- Move anything stored near the joints
- For business premises, tell us about site rules or sign-in
- For indoor joints, keep the area dry beforehand if you can
Getting a quote
For a quick quote, get us on the phone, or send an email if you’d rather. Tell us about the joints that need doing and we’ll talk you through the work.
Advice
When it is not the sealant
To be straight with you, some problems need a different trade:
- Cracking across the wall rather than at a joint
- Damp that is not coming from the joint
- Loose or hollow render, which needs re-rendering
If in doubt, send an email to info@mrmastic.co.uk and we’ll say what we think.
What we seal
- Render & cladding joints
- Façade panels
- Joints between brick and frames
- Brickwork movement joints
- Copings & trims
- Concrete & block
Do you need external mastic in Lochwinnoch?
Some movement joints have been pointed up with mortar, often by someone who didn’t know what it was for. The joint can’t move, so the wall cracks somewhere else instead.
Most people get in touch when they notice something like this:
- Water getting into walls through failed joints
- Movement joints with cracked, split or missing sealant
- Leaking joints around cladding and façade panels
- Weathered mastic that no longer stretches
In and around Lochwinnoch, as anywhere, good external mastic starts with a clean, dry, properly prepared joint.
What your quote should include
- Which sealant they’ll use, and why
- How the colour is chosen
- How much experience the applicator has
- What the quote includes, VAT included or not
Work for landlords, hotels and businesses
Mouldy or split sealant often shows up at the end of a tenancy, and it’s quick to put right between tenancies. Several properties can be quoted together.
In hotels, rooms out of use cost money, so the work can be planned room by room around your bookings where we can. We’ve worked in hotels as well as homes and businesses.