Inverclyde · Scotland
External Mastic in Port Glasgow
Professional external mastic in and around Port Glasgow, with every bit of old sealant taken out first.
- Gaps where render, brick and frames meet
- Joints pointed up with cement by mistake
- Panel joints letting water in
External mastic in Port Glasgow
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. We’re often asked to deal with brick movement joints where the sealant has split and moss and dirt in joints with no sealant left, on concrete & block, render & cladding joints and copings & trims.
In a town like Port Glasgow, older stone-built streets sit alongside newer estates with brick, render and uPVC rooflines. Older buildings tend to leak at gutter joints, newer ones at dried-out movement joints.
The work is covered for a year after we finish. If there’s a problem with it, please email us at info@mrmastic.co.uk.
- Location
- Port Glasgow (PA14, PA15)
- Wider area
- Inverclyde
- Cover
- 12 months on all our work
- Quote
- A clear price before work begins
- info@mrmastic.co.uk
- Updated
- 26 October 2026
What the job involves on each surface
Brickwork movement joints
Vertical joints in long brick walls let the brickwork expand without cracking. We reseal them with a low-modulus sealant over backing rod.
Joints between dissimilar materials
Joints where frames, sills or panels meet the wall are common leak points. The old joint is removed and a sealant that bonds to both sides goes in.
Towns and villages near Port Glasgow
More services for Port Glasgow
Can I do it myself?
Overfilling a joint is a classic DIY mistake. A heavy bead looks messy and copes badly with movement, and getting the depth right matters as much as the look.
The biggest DIY mistake is sealing over old sealant. 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.
Do you need external mastic in Port Glasgow?
Joints sealed without backing rod, or far too deep, rarely last. Sealant bonded to three sides has nowhere to go and rips as the joint opens.
Signs it’s time to call us include:
- Rain getting behind render or cladding at a joint
- Movement joints with cracked, split or missing sealant
- Joints pointed up with cement by mistake
- Cracked joints where brick meets render or frames
Homes close to Clune Park Church include some older properties, and the joints between older walls, newer extensions and the roofline need a sealant that can move.
Before you book anyone
- How the surfaces are prepared before sealing
- How much experience the applicator has
- Which sealant they’ll use, and why
- The length of the guarantee
Honest limits
Some problems need a builder, plumber or other trade rather than us:
- Adding movement joints to masonry that has none
- Rising or penetrating damp from elsewhere in the wall
- Structural movement, which needs a surveyor or engineer
If you’re not sure, just drop us a line at info@mrmastic.co.uk and we’ll give you a straight answer.
What we seal
- Copings & trims
- Concrete & block
- Brickwork movement joints
- Façade panels
- Joints between brick and frames
- Render & cladding joints
How the visit works
Good joint work is mostly preparation, and we don’t rush it. Every joint is cleaned and dried before new material goes in. In total, it usually takes anything from a few hours to several days, depending on the building. For a job in Port Glasgow, tell us where the work is, how to get in and where to park. Outdoor jobs need a dry day, so they can move if the weather turns.
- 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.
- Backing rod goes in next, setting the depth and keeping the sealant off the back of the joint.
- We gun in a flexible exterior sealant in a colour that suits the wall and tool it neatly.
How to prepare
- Mention any leaks or damp you’ve noticed
- Mention if the joints have been sealed before
- For business premises, tell us about site rules or sign-in
Ask for a quote
Every job is quoted individually. Simply email us at info@mrmastic.co.uk and describe the job.
Advice
Looking after it afterwards
No joint lasts for ever, but care makes a real difference. A few tips:
- Keep high-pressure jets off the joints
- Leave the joints unpainted unless we have said otherwise
- Keep soil, plants and ivy away from the joints
- Act on the first splits you see
Avoid pressure-washing straight into the joints. A strong jet can damage the edges of the bead and let water in behind.
Water getting behind cladding or render can go unnoticed for a long time. When it finally shows inside, the joint may have been open for years, so it’s worth resealing at the first signs.
What affects the cost of external mastic
Some jobs are bigger than they look, and some smaller. What affects the quote:
- Access and height
- Whether old sealant or filler has to be cut out
- How many rooms, windows or areas are involved
- The amount of work
We do not show prices on the website, because each job is priced on what it involves. For a quick quote, please email us at info@mrmastic.co.uk.
Asking for a quote
Before you ask for a quote, have a think about:
- Whether it has been sealed before
- The address or postcode of the job
- Roughly how big the job is
- The problem you’ve noticed
Getting a quote is simple: let us know what needs doing and where. Photos by email help us understand the job, and we’ll take it from there.
Common questions in Port Glasgow
Is Port Glasgow in your area for external mastic?
Yes, Port Glasgow is within the area we cover. Our work covers the whole of Scotland. Just drop us a line at info@mrmastic.co.uk with a few details of the job.
Is external mastic in a coastal place like Port Glasgow any different?
Coastal weather is harder on outside sealant: there’s more wind-driven rain and, closer to the shore, salt in the air. Choosing the right sealant for the frame and wall, laid at the right depth, helps it last.
Can a movement joint be filled with mortar?
No. Rigid materials cannot move with the wall and the joint fails. If it has already been filled, we can usually cut it out and reseal it.
Can you do several jobs on one visit?
Yes, and it often makes sense. Combining jobs makes good use of the visit, so mention them when you ask for a quote.
Are you insured?
Yes. We’re fully insured, and we have been doing sealant work for more than 20 years.
Do the sealants smell?
It depends on the product. Some smell for a while, some hardly at all.
Do you work at height?
Each building is different. Send us pictures and a rough idea of the height, and we’ll confirm what access is needed.
Do I have to be there?
Access is agreed with you when the job is booked. For inside work, that normally means someone being in.
Port Glasgow buildings and the weather
Port Glasgow is within about 1 mile of the coast, and homes near the sea take more wind-driven rain, with salt in the air closer to the shore. That is hard on movement joints and outside wall joints, especially on the side facing the sea. Port Glasgow is in the west of Scotland, which is wetter than the east, so there’s plenty of rain for movement joints and outside wall joints to keep out.
For landlords with property near Port Glasgow station, split movement joints are easy to miss on a rental until damp shows inside.
Port Glasgow is about 12 miles north-west of Paisley, in Inverclyde. Whether you are in the middle of Port Glasgow or further out, we cover external mastic for every kind of property, from flats and houses to offices and hotels. Our area takes in 19 places across Inverclyde. We also work in Glasgow, around 16 miles away.
Our applicators cover all of the PA14 and PA15 postcode area for external mastic. External mastic is available to properties on Stanton Square, Ardmore Road and Montgomerie Street and the roads around them. Being close to the A8 and A761, Port Glasgow is easy for our applicators to reach for external mastic. Close by, we work in Mid Auchinleck (1 mile south-east), Bardrainney (1 mile south-east), Woodhall (1 mile east), Bogston (1 mile north-west) and Cardross (3 miles north). Within a short drive, we also cover Greenock (4 miles west), Gourock (6 miles west), Kilmacolm (3 miles south-east), Braeside (6 miles west), Inverkip (7 miles west) and Branchton (5 miles west).
Around Port Glasgow
For rail, the closest station is Port Glasgow station, about 0.6 miles north-west of the centre. A little further out are Finlaystone House - Doll Collection (2.2 miles east) and Broadfield Hospital (1.3 miles east). For a walk, there’s Lyle Hill.