Shetland Islands · Scotland
Haroldswick Sand Mastic
We cover Haroldswick for traditional burnt sand mastic around sash and case windows and doors in stone and brick. Old material cut out, joints cleaned and sealed neatly.
- Tired mastic found when preparing windows for paint
- Draughty sash windows at the surround
- Patchy fillers round a sash window
What we can’t put right
It helps to know what we can’t do:
- Sashes that need overhauling
- Cracked or broken glass
- Planning or listed building consent (your local planning authority decides)
Not sure which it is? You can drop us a line at info@mrmastic.co.uk and we’ll tell you honestly.
Surfaces we seal
- Sash and case windows
- Timber door frames
- Tenement windows
- Period & listed homes
- Stone surrounds
- Brick reveals
Sand mastic for homes and businesses in Haroldswick
Sand mastic suits most period window surrounds. Newer frames usually get a flexible sealant instead and we’ll explain which is best for yours. If you are dealing with mastic that needs renewing before redecorating and mastic worn away on windows facing the weather, we can help.
Many older Scottish homes still have timber windows set into stone walls. Those suit a traditional sand mastic or a neutral-cure sealant, not an acetoxy silicone that can attack some stone.
We stand behind the work with a 12-month guarantee, so you’re not left on your own once the job is done.
- Location
- Haroldswick (ZE2)
- Region
- Shetland Islands
- Cover
- A year, on every job
- Quote
- A clear price before we start
- info@mrmastic.co.uk
- Last updated
- 26 October 2026
Windows and doors 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. That is hard on the mastic around older windows and doors, especially on the side facing the sea. Many older homes in Scotland have sash and case windows, often pointed into the wall with traditional sand mastic.
Homes close to St John's Church include some older properties, and frames set in older brick or stone need a sealant that suits the wall as well as the frame.
Haroldswick is in the Shetland Islands. Whether you’re in the middle of Haroldswick or further out, we cover sand mastic for every kind of property. Across the Shetland Islands, we cover 63 places, and Haroldswick is one of them.
Every address in ZE2 is within our area for sand mastic, from the main roads to the quietest streets. That includes homes and businesses on Taftens, Nordabrake and Brakefield Crescent and the roads around them. Being close to the B9087, Haroldswick is easy for our applicators to reach. We also cover Baltasound (3 miles south-west), Clivocast (8 miles south), Cullivoe (9 miles south-west), Houbie (14 miles south) and Camb (15 miles south-west). Island and remote addresses take a little more planning, so tell us where you are when you ask for a quote.
What’s near Haroldswick
Well-known places in the area include Unst Heritage Centre (0.6 miles south-west). The countryside around Haroldswick includes Little Heog and Loomer Shun.
How it works
Good joint work is mostly preparation, and we do not rush it. Joints are cleaned back and dried before anything new goes in. All told, the work takes a few hours per window, depending on the condition of the joints. For a place like Haroldswick, longer drives are planned in advance. Mention tracks, gates, ferries or anything else about the route.
- We check each window surround and the condition of the joint.
- We rake out the old mastic and clean the joint.
- We fill deep gaps so the new mastic is not too thick.
- New sand mastic is applied and shaped by hand.
- We finish the mastic to a tidy line.
Before we arrive
- Keep children and pets away from the work area
- Mention any parking rules near the property
- For business premises, tell us about site rules or sign-in
How to get a quote
We don’t publish a price list. Instead, we send you a clear quote for your job. To arrange one, send an email to info@mrmastic.co.uk.
Related advice
Haroldswick: your questions answered
Does the coastal weather in Haroldswick affect outside sealant?
Coastal weather is harder on outside sealant: there’s more wind-driven rain and, closer to the shore, salt in the air. The right product, a clean joint and the right depth all help it cope.
Is Haroldswick within the area you cover?
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.
Which is right for my windows, sand mastic or modern sealant?
It depends on the window. On many period windows, sand mastic looks right and suits the building and newer frames normally get a flexible sealant.
Do you take out the old sealant first?
Yes, every time. New silicone doesn’t stick to old silicone, so any old material comes out before anything new goes in.
Can you replace silicone on a period window with sand mastic?
Usually, yes. With the silicone removed and the joint cleaned we point it with sand mastic.
Do I have to be there?
It depends on the job. For work indoors, someone needs to let us in.
Will you leave a mess?
Not at all. We work neatly, protect the area around the joints and tidy up afterwards.
What information do you need?
The location, the problem and the rough size of the job. Photos by email help too.
Other services in Haroldswick
DIY versus a professional finish
Too much sealant is as bad as too little. A heavy bead looks messy and copes badly with movement, and getting the depth right matters as much as the look.
The difference is mostly in the preparation and the product. Joints are cleaned back to sound surfaces and dried, and the sealant is matched to the joint and its conditions, then guaranteed for a year.
Landlord and commercial work in Haroldswick
From a single let to a portfolio, you get the same standard of work: the old material taken out, careful preparation and a 12-month guarantee.
We work for landlords and agents as well as householders. Resealing between tenancies keeps a property looking cared for before the next move-in.
Different surfaces, different methods
Brick reveals
Sand mastic is also used where timber frames meet brick. It suits older brickwork.
Stone surrounds
Sand mastic sits naturally against stone. The finish blends with the masonry.
Aftercare tips
A little care helps the new joints last. Our advice:
- Check the mastic when you check the paintwork
- Keep modern sealant off the mastic
- Do not paint over the new mastic
- Make sure water runs off the sill
Do not touch or press the mastic while it hardens. It skins over quickly, but takes longer to harden fully.
Gaps round a sash box let in draughts and rain. Left, the gap tends to get bigger as more mastic falls out.
When to call us in Haroldswick
Timber frames move with the seasons. The movement cracks the mastic little by little.
Signs it’s time to call us include:
- Cracked mastic round a front door frame
- Modern sealant on a period surround
- Draughts and rain around sash boxes
- Gaps where the frame meets the masonry
Around Haroldswick, as everywhere, sand mastic is only as good as the preparation behind it.
Comparing quotes
- Whether you can choose the colour
- How much experience the applicator has
- How the surfaces are prepared before sealing
- Whether the sealant suits the joint