North Lanarkshire · Scotland
Window & door mastic in Harthill, North Lanarkshire
Mastic around window and door frames, sills and patio doors for homes and businesses in Harthill and across North Lanarkshire. Fully insured, ARBOMaster approved and guaranteed for a year.
- Old mastic that has gone black or come away
- Cold air getting in at the frame edge
- White mastic on grey or black frames
Window mastic in Harthill, done properly
There are two joints on most windows. Outside, the mastic keeps rain out; inside, the joint between frame and plaster stops draughts and tidies the reveal. Either or both can be done. We’re often asked to deal with old mastic that has gone black or come away and whistling draughts around closed windows, on timber windows & doors, aluminium frames and patio & French doors.
Across smaller places in Scotland, homes range from stone and harled cottages to newer houses, many standing in the open. Exposed frames and sills take the full force of wind-driven rain, so the mastic there works hard.
There’s a 12-month guarantee on every job, whatever its size.
- Where
- Harthill (ML7)
- Wider area
- North Lanarkshire
- Guarantee
- 12 months on all our work
- Price
- A clear price before any work starts
- info@mrmastic.co.uk
- Page updated
- 26 October 2026
Why act early in Harthill
The work is quick compared with the damage it prevents: the visit takes most of a day for a typical house, less for a few frames. Leave it until water is coming in and you may need plastering and decorating as well. 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.
There are no prices on our website, because each job is priced on what it involves. Call for a quick quote.
What you get with us
- Sanitary silicone with an anti-fungal additive in wet areas
- An ARBOMaster approved applicator
- Sealant colour chosen to suit
- We agree the colour with you first
See how sealant jobs are priced and our reviews.
What sealant work can’t fix
A few problems are outside what sealant work can do:
- A sash or casement that will not close properly
- Rotten timber, which needs a joiner first
- Misting between the panes of a double-glazed unit (that needs a new unit)
Not sure which it is? You can email us at info@mrmastic.co.uk and we’ll tell you honestly.
Where we work in Harthill
- Composite doors
- Patio & French doors
- uPVC windows
- Aluminium frames
- Timber windows & doors
- Window sills
Looking after it afterwards
After the cure time, these simple habits help:
- Look round the frames every year or so
- Paint up to the joint, not over it
- Do not aim a pressure washer at the joints
- Keep timber frames painted
Keep the new mastic undisturbed while it cures, for as long as we advise. Keep jet washers away from the frames.
On timber windows, water behind the joint can lead to rot. Once wood has rotted, it needs repair before it can be sealed, so it pays to reseal before that happens.
For landlords and businesses
For anyone letting property in or around Harthill, several properties can go on one quote. Just tell us the addresses and what each one needs, and pictures by email help.
We work for letting agents and landlords as well as homeowners. Resealing between tenancies is a simple way to keep a property in good order before the next move-in.
Frames and glazing around Harthill
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. Many older homes in Scotland have sash and case windows, often pointed into the wall with traditional sand mastic.
If you let a flat or house near Blackridge station, cracked frame mastic tends to show up as a draught or damp complaint, so it’s worth checking between lets.
Harthill is about 5 miles south-west of Bathgate, in North Lanarkshire. Whether you are in the middle of Harthill or further out, we cover window mastic for every kind of property. Across North Lanarkshire, we cover 89 places, Harthill among them. You can also see our page for Glasgow, roughly 20 miles from Harthill.
All of ML7 is within our area for window mastic. Whether your property is on West Main Street, Mclauchlan View and Miller Street or anywhere close by, our applicators can take on the job. We also cover the places around Harthill: Greenrigg (1 mile east), Eastfield (1 mile south-west), Blackridge (2 miles north), Westrigg (2 miles north) and Fauldhouse (3 miles south-east). We also work in nearby towns such as Motherwell (10 miles south-west), Cumbernauld (11 miles north-west), Coatbridge (11 miles west), Airdrie (9 miles west), Wishaw (9 miles south-west) and Bellshill (11 miles west).
What’s near Harthill
The nearest railway station is Blackridge station, roughly 1.6 miles north of the centre. Nearby you will also find Blackridge Community Museum (1.7 miles north) and Tippethill House Hospital (2.7 miles north-east). Not far away are Black Loch.
Do you need window mastic in Harthill?
A lot of older mastic was never designed to stay flexible. Once it has hardened, the frame’s movement tears it from the wall, leaving a hairline gap down one side.
If you can see any of these, it’s time to have the joints looked at:
- Whistling draughts around closed windows
- Rushed sealant from a window installation
- Gaps where the sill meets the wall
- Draughty joints inside around the window
In and around Harthill, as anywhere, good window mastic starts with a clean, dry, properly prepared joint.
Questions to ask before booking
- Is the old sealant removed completely?
- Whether the sealant suits the joint
- Whether VAT is included
- Whether they’re fully insured
Also near Harthill
Other services in Harthill
How the job changes by surface
Aluminium frames
Coated aluminium needs a compatible sealant and we avoid acetoxy silicones, which can react with some metals. Neutral-cure sealant is the safe choice.
Patio & French doors
Patio and French doors have the longest joints on most houses. Most leaks start at the bottom corners, so we pay close attention there.
What happens on the day
On the day, we look over the joints with you first, so there are no surprises. Surfaces next to the work are protected before any work begins. The work normally takes anything from an hour or two to a full day, depending on how many frames there are. Somewhere like Harthill may be a longer drive, and the journey is planned ahead. Tell us about tracks, gates, a ferry crossing or anything unusual about getting there.
- We check how each frame can be reached safely.
- All the failed sealant is cut away.
- The surfaces are cleaned and left dry.
- Deep voids are backed, then the sealant is gunned in.
- The joint is shaped to shed water and the area tidied.
Preparing for the visit
- Tell us about any previous sealing or DIY attempts
- Where the joints are inside, avoid wetting them before we arrive
- Keep pets and children clear of the area while we work
How to get a quote
Asking for a quote is easy: let us know what needs doing and where. A few photos by email make the job easier to understand, and we’ll come back to you with a quote.
Advice
Common questions in Harthill
Do you work for landlords with property near Blackridge station?
Yes, we work for letting agents and landlords. Just drop us a line at info@mrmastic.co.uk and tell us about the property, and we’ll give you a clear quote.
Will you come out to Harthill?
Yes, Harthill is covered. We work across all of Scotland, from towns to the smallest places. The journey is planned ahead, so it helps to know about access.
Will there be a smell?
Possibly a little. It fades as the sealant cures.
Do you have sealant for grey or black windows?
Yes. We can use white, brown, anthracite grey, black or clear.
How long should I leave it?
Most sealants are touch-dry well before they’re fully cured. We’ll tell you how long to leave the joint.
Can resealing stop a draught around my window?
Often, yes. The gap between frame and wall is a common source of draughts, and resealing inside and out closes it.
What do you need from me for a quote?
Only a few details: the address or postcode, what’s wrong and any access issues. Then send an email to info@mrmastic.co.uk.
What sealant do you use?
We choose the sealant for the joint, not the other way round. Movement, water and weather all affect the choice, and we’ll explain our choice.