Shetland Islands · Scotland
Window Mastic in Haroldswick
Mastic around window and door frames, sills and patio doors for homes and businesses in Haroldswick and across the Shetland Islands. Fully insured, ARBOMaster approved and guaranteed for a year.
- Draughty joints inside around the window
- A bead that doesn’t match the frame
- Water coming in at the bottom corners of a door
How we handle window mastic in Haroldswick
The mastic around a window or door seals the gap between the frame and the wall. Once that seal fails, wind and rain find the gap. The old mastic is removed and the joint resealed with a flexible exterior sealant. We work on aluminium frames, window sills and timber windows & doors, and the jobs we see most are cracked internal joints between frame and plaster and white mastic on grey or black frames.
Outdoor sealant needs a dry surface, so window work around Haroldswick is planned around the weather, and longer journeys are planned in advance. Let us know about access to every frame, including any upstairs.
Each job carries a 12-month guarantee, large or small.
- Location
- Haroldswick (ZE2)
- Region
- Shetland Islands
- Cover
- One year on every job
- Quote
- A clear price before work begins
- info@mrmastic.co.uk
- Last updated
- 26 October 2026
Quotes for window mastic in Haroldswick
The quote reflects the job in front of us. We look at:
- Any working-time requirements on site
- Mould in or behind the old joints
- The type of sealant required
- The old material and how stubborn it is
A few things move the cost up or down: the old material and how easily it comes out, any mould to treat, and whether the work is at height. Your quote takes all of that into account.
Helping us quote
A few details help us give you an accurate quote. When you get in contact, it helps to mention:
- Roughly how big the job is
- Access, such as stairs, a lift or height
- The type of property
- A few pictures by email, if you can
We quote each job on its own. Simply drop us a line at info@mrmastic.co.uk and describe the job and send pictures if you have them.
Other services in Haroldswick
How it works
Once we are on site, we check the joints match what you told us. If anything is different, we explain it before carrying on. After that, the work takes a morning for a couple of windows and a door. Somewhere like Haroldswick 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 start by checking each window and door with you.
- Next the failed sealant is cut away and the joint cleaned.
- Where gaps are deep, backing rod goes in first.
- A flexible, weatherproof sealant is applied in a colour to suit the frame.
- We clear up and check every joint is fully closed.
Preparing for the visit
- Move anything stored near the joints
- Let us know about stairs, lifts or work at height
- Let us know about parking restrictions
Getting a quote
If you’re in Haroldswick and need window mastic, send an email to info@mrmastic.co.uk. Tell us what the problem is and where, and we’ll agree the price before any work begins.
Advice
Can I do it myself?
A DIY attempt does not rule out a professional job. We remove it and do the joint properly.
Sealing over old silicone is the commonest DIY error. Silicone doesn’t stick to old silicone, so it peels away and traps moisture behind it. All the old material has to come out first.
For landlords and businesses
A neglected joint can let water reach the structure, which is a bigger problem in a rented property. Resealing at the right time is simple maintenance that we can handle for you.
Mouldy or split sealant often shows up at the end of a tenancy, and it’s easy to sort out between tenants. We can quote for more than one property at once.
Common questions in Haroldswick
Will you come out to Haroldswick?
Yes, we do. We work across all of Scotland, islands included, and smaller places are part of that. Longer journeys are simply planned in advance.
Is window mastic in a coastal place like Haroldswick any different?
Coastal homes put outside sealant through more weather than inland ones, so the choice of sealant and the preparation matter even more. It’s worth checking the walls that face the sea first.
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 will tell you what we’re using.
Can you work on commercial sites?
Yes. We can plan bigger jobs in stages to suit the site.
How many windows can you do in a day?
A few frames take a few hours. We confirm the timing with your quote.
Can landlords and businesses book you?
Yes. Domestic, commercial and hotel work are all part of what we do, and we’re fully insured.
Is it worth trying it myself?
Some simple jobs can be done by a careful DIYer. The usual mistakes are sealing over old sealant, sealing a damp joint and using too much.
Do the sealants smell?
It depends on the product. Some products have a noticeable smell, others very little, and any smell fades as they cure.
How to look after the new joints
No joint lasts for ever, but care makes a real difference. A few tips:
- Paint up to the joint, not over it
- Use gentle cleaners on frames and sealant
- Clear any debris from frame drain holes
- Look round the frames every year or so
Most silicone sealants won’t take paint, so mention any painting plans before work begins. There are paintable sealants for joints that need it.
Leaks normally show up in wet, windy weather, but sealant goes on best when frames and walls are dry. Sorting cracked mastic early means the joint is sound before the bad weather.
What window mastic looks like in Haroldswick
Haroldswick is within about 2 miles of 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.
Around Haroldswick, as everywhere, window mastic is only as good as the preparation behind it. For an older house near a landmark such as St John's Church, the windows may be timber, sash or later replacements, and each needs the right sealant against the wall.
Haroldswick is in the Shetland Islands. Whether you’re in the middle of Haroldswick or further out, window mastic is available for homes and businesses alike. Our area takes in 63 places across the Shetland Islands, large and small.
We work across the ZE2 postcode area for window mastic. Local streets include Taftens, Nordabrake and Brakefield Crescent, and we cover them all. Being close to the B9087, Haroldswick is easy for our applicators to reach for window mastic. We also cover the places around Haroldswick: Baltasound (3 miles south-west), Clivocast (8 miles south), Cullivoe (9 miles south-west), Houbie (14 miles south) and Camb (15 miles south-west). Remote and island addresses need a little more planning, so tell us where you are when you ask for a quote.
Local landmarks in Haroldswick
Well-known places in the area include Unst Heritage Centre (0.6 miles south-west). For a walk, there’s Little Heog and Loomer Shun.
When something else is needed
It helps to know what we can’t do too:
- Penetrating damp from a failed cavity tray or render
- Rotten timber, which needs a joiner first
- A sash or casement that will not close properly
Not sure which it is? You can drop us a line at info@mrmastic.co.uk and we will tell you honestly.
Surfaces we seal
- Composite doors
- Timber windows & doors
- Window sills
- Aluminium frames
- uPVC windows
- Patio & French doors
How the job changes by surface
Aluminium frames
Aluminium moves with heat, and the frames are often slimmer than uPVC. A neat, narrow bead in a colour to match keeps the clean look.
Timber windows & doors
Soft or rotten wood can’t be sealed successfully. We’ll point out any rot we find, as that’s a job for a joiner.