Argyll and Bute · Scotland
Dunoon Window Mastic
Mastic around window and door frames, sills and patio doors in Dunoon, with a 12-month guarantee on every job. Ask us for a quote.
- Cracked internal joints between frame and plaster
- Water coming in at the bottom corners of a door
- Rushed sealant from a window installation
How we handle window mastic in Dunoon
Frames and walls do not move together. Plastic and aluminium frames move with the temperature, while masonry stays fairly still. That’s why the joint needs a flexible, low-modulus sealant rather than something rigid. We work on uPVC windows, window sills and aluminium frames, and the jobs we see most are hard, cracked sealant around windows and whistling draughts around closed windows.
Many older Scottish homes still have timber windows set into stone walls. The sealant has to suit the stone, which rules out acetoxy silicones that can mark or attack it.
Whatever the size of the job, it’s backed by our one-year guarantee in Dunoon and across Argyll and Bute.
- Where
- Dunoon (PA23)
- Wider area
- Argyll and Bute
- Cover
- A year, on every job
- Quote
- A clear quote up front
- info@mrmastic.co.uk
- Updated
- 26 October 2026
Dunoon homes and the weather
Dunoon is close to the coast, where wind-driven rain is a fact of life and, nearer the shore, so is salt air. Both are hard on the mastic around window and door frames, which can dry out and crack sooner where a building faces the weather. Private landlords in Scotland must meet the Repairing Standard, which includes keeping a home wind and watertight, and sound outside sealant is part of that.
Schools such as Dunoon Primary School And Janitor's House are buildings too, and larger buildings have plenty of frames, and the mastic around each one ages. If you let a flat or house near Inverkip station, renewing tired window mastic between tenants heads off draught and damp complaints.
Dunoon (Gaelic: Dùn Obhainn) is about 6 miles west of Greenock, in Argyll and Bute. Whether you’re in the middle of Dunoon or further out, we cover window mastic for every kind of property, from flats and houses to offices and hotels. Dunoon is one of 118 places in Argyll and Bute where we work for window mastic. For nearby work, see our Glasgow page (26 miles or so).
Postcode districts we cover here for window mastic: PA23. You will find streets such as Queen Street, Queens Court and Pilot Street. Dunoon is on the A815 and A885, so it’s easy for us to get to. Close by, we work in Kirn (1 mile north-east), Hunters Quay (1 mile north-east), Bullwood (2 miles south), Sandbank (2 miles north) and Strone (2 miles north). Within a short drive, we also cover Helensburgh (9 miles north-east), Rothesay (10 miles south-west), Rhu (7 miles north-east), Garelochhead (10 miles north-east), Port Bannatyne (9 miles south-west) and Innellan (5 miles south). Being one of Argyll and Bute’s larger places, Dunoon has every kind of property, from flats to offices. If you’re somewhere remote, the job takes a little more planning, so let us know when you get in touch.
Landmarks near Dunoon
Typical jobs here are in homes near Dunoon Grammar School. For rail, the closest station is Inverkip station, about 3.9 miles south-east. Well-known places in the area include Dunoon Castle (0.6 miles south) and Castle House Museum (0.6 miles south). The countryside around Dunoon includes Loch Loskin.
What happens on the day
When we get to you, we compare the joints with what we discussed. If we find something unexpected, we talk it through with you first. After that, the work takes anything from an hour or two to a full day, depending on how many frames there are. Outdoor work around Dunoon depends on the weather, as sealant needs a dry surface, so external jobs may need to move if the day turns wet. Work indoors isn’t affected.
- We check each frame and agree which ones need doing.
- Next the failed sealant is cut away and the joint cleaned.
- We fit backing rod in deep gaps so the sealant is the right depth.
- A flexible, weatherproof sealant is applied in a colour to suit the frame.
- Finally we tidy up and check each joint.
How to prepare
- Where the joints are inside, avoid wetting them before we arrive
- Mention any leaks or damp you’ve noticed
- Keep children and pets away from the work area
Get a quote
To get a quote, email us at info@mrmastic.co.uk and tell us where the job is and what the problem looks like. We will send you a clear quote before any work starts.
Advice
Different surfaces, different methods
Window sills
The end joints of a sill tend to fail before the rest. We reseal them so rain can’t run into the wall.
Aluminium frames
Aluminium needs a sealant that bonds to coated metal, and acetoxy silicones aren’t used, as they can attack some metals. Neutral-cure sealant is the safe choice.
What affects the cost of window mastic
The price is agreed before any work begins. It takes into account:
- The type of sealant required
- Mould in or behind the old joints
- Any working-time requirements on site
- The number of rooms or windows
Some things make a job bigger or smaller: how much old sealant there is and how stubborn it is, whether mould needs treating, and whether we need extra access for height. Your quote takes all of that into account.
Helping us quote
When you contact us, these details help:
- Pictures of the joints, sent by email
- Whether it’s a home or a business
- Roughly how big the job is
- Where the job is, and your postcode
Want a quote for window mastic? Please email us at info@mrmastic.co.uk and tell us about the job. You’ll know what we plan to do, and what it will cost, before any work begins.
Looking after it afterwards
After the cure time, these simple habits help:
- Air rooms to keep condensation down around windows
- Look round the frames every year or so
- Repaint timber before it’s bare
- Avoid harsh chemicals near the mastic
A yearly look round the frames is enough. Small splits are simple to catch before they leak.
Water gets in quietly when mastic fails. You might not see it until plaster blows or a damp patch appears inside. Early resealing stops it reaching that point.
What sealant work cannot fix
It helps to know what we cannot do too:
- Soft or decayed wood in the frame
- Damp problems in the wall away from the window
- A sash or casement that won’t close properly
If you’re not sure, just email us at info@mrmastic.co.uk and we will give you a straight answer.
Surfaces we seal
- Patio & French doors
- Timber windows & doors
- Window sills
- uPVC windows
- Composite doors
- Aluminium frames
FAQs for Dunoon
Do you work for landlords with property near Inverkip station?
Yes, rental work is part of what we do. You can send an email to info@mrmastic.co.uk with the address and a few details, and we will give you a fixed price before we start.
Is Dunoon within the area you cover?
Yes, smaller places are covered as well as towns. We work across all of Scotland. Just mention lanes, gates or anything else about the route when you book.
When is the sealant fully cured?
Most sealants are touch-dry well before they’re fully cured. We will tell you how long to leave the joint before we leave.
Do I need to be at home?
If the work is inside, we need someone to let us in. Once we’ve agreed the job, you do not need to watch us work.
Are you ARBOMaster approved?
Yes. We’re approved under the ARBOMaster scheme.
What do you put in the joint?
We choose the sealant for the joint, not the other way round. Where it moves, gets wet or faces the weather makes a difference, and we’ll tell you what we’re using.
Can resealing stop a draught around my window?
Yes, where the draught is at the frame edge. We find where the air is coming from before we reseal.
Can you seal the gap between the frame and the plaster indoors?
Yes. Outside is the weather seal; inside closes the gap to the plaster. We can do either or both.
What we are called out for in Dunoon
On timber frames, paint and putty build up around the joint. Old mastic gets painted over and cracks under the paint, and the wood moves with damp as well as heat.
The problems people generally mention when they call include:
- Old mastic that has gone black or come away
- Untidy mastic left by window fitters
- Draughty joints inside around the window
- Water coming in at the bottom corners of a door
For an older house near a landmark such as St John’s Church (Dunoon), the windows may be timber, sash or later replacements, and each needs the right sealant against the wall.
Before you book anyone
- Which sealant they’ll use, and why
- Whether VAT is included
- How the joint is cleaned and prepared
- What insurance they hold
Other services in Dunoon
Why act early in Dunoon
Choosing the product is half the job. Interior caulk and bathroom silicone aren’t made for exterior frame joints. A low-modulus exterior sealant keeps its stretch through hot and cold weather. 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.
We do not show prices on the website, because each job is priced on what it involves. For a quick quote, please drop us a line at info@mrmastic.co.uk and we will talk you through it.
Why Dunoon customers choose us
- More than 20 years in sealant work
- Old sealant always removed completely
- Tidy, careful work
- Domestic, commercial and hotel work
Take a look at our cost guide or our reviews.