Shetland Islands · Scotland
External Mastic in Haroldswick
Sealing brickwork movement joints, render, cladding and façade joints for Haroldswick, backed by a one-year guarantee. Call for a quick quote.
- Damp patches traced to an open external joint
- Joints with sealant missing in places
- Panel joints letting water in
External mastic in Haroldswick
Failed sealant is cut out, the depth set with closed-cell backing rod, and the joint resealed with a low-modulus sealant made for outside. The colour is chosen to suit the brick or render. Typical jobs include plants rooting in failed movement joints and sealant pulling away from one side of the joint, on joints between brick and frames, brickwork movement joints and concrete & block.
External sealant needs dry surfaces, so outdoor work around Haroldswick is planned around the weather, and longer journeys are planned in advance. Let us know about access to every wall and roofline.
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.
- Place
- Haroldswick (ZE2)
- Region
- Shetland Islands
- Cover
- A year, on every job
- Quote
- A clear price before any work starts
- info@mrmastic.co.uk
- Page updated
- 26 October 2026
Looking after it afterwards
Joint life depends on how it’s used and looked after. Here’s what we suggest:
- Keep water from gutters off the wall
- Show decorators and builders where the movement joints are
- Check external joints each spring
- Leave the joints unpainted unless we have said otherwise
Have a quick look at the joints each spring. Splits, gaps at the edges or plants in the joint are early warning signs.
Once a joint cannot move, the wall finds another way, generally as cracking in the brickwork or render nearby. Resealing it early helps prevent that.
How the visit 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 few hours to a few days, depending on the length of joint and the access. Around Haroldswick, distance and access matter more than parking. Let us know how to find you and how to reach the joints.
- We inspect the joints and agree which need resealing and how they’ll be reached.
- We cut out the failed sealant and rake out any dirt or growth.
- Both sides are cleaned back to sound material and primed if needed.
- We push in closed-cell backing rod so the sealant is the right depth and bonds to the sides only.
- A flexible exterior sealant is applied and tooled in a colour to suit the wall.
Before we arrive
- Let us know if you’ve seen damp or leaks
- Mention any parking rules near the property
- Let us know about stairs, lifts or work at height
Ask for a quote
Quotes start with a quick conversation. Describe the problem, the location and the size of the job, and we will talk you through what we’d do. Whenever you are ready, send an email to info@mrmastic.co.uk.
Read more
Haroldswick buildings and the weather
Haroldswick is within about 2 miles of the coast, and homes near the sea take more wind-driven rain, with salt in the air closer to the shore. That’s hard on movement joints and outside wall joints, especially on the side facing the sea. Island weather, with its wind and salt spray, is tough on movement joints and outside wall joints.
Around Haroldswick, as everywhere, external mastic is only as good as the preparation behind it.
Haroldswick is in the Shetland Islands. From the centre of Haroldswick to the outskirts, external mastic is available for homes and businesses alike, from flats and houses to offices and hotels. Our area takes in 63 places across the Shetland Islands, large and small.
We cover every part of ZE2 for external mastic and the streets around it. If you need external mastic at a property on Taftens, Nordabrake and Brakefield Crescent or anywhere close by, our applicators can take on the job. You will find Haroldswick on the B9087, so it’s easy for us to get to with everything needed for external mastic. Close by, we work in 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.
Near you in Haroldswick
Nearby you’ll also find Unst Heritage Centre (0.6 miles south-west). Not far away are Little Heog and Loomer Shun.
Haroldswick: your questions answered
Does living near the coast affect external mastic in Haroldswick?
Near the coast, wind-driven rain and, nearer the shore, salt air make outside sealant work harder. Choosing the right sealant for the frame and wall, laid at the right depth, helps it last.
Is Haroldswick within the area you cover?
Yes. Haroldswick is within the area we cover, which takes in towns, villages and rural addresses. We work across all of Scotland, including the islands, where work is planned around ferry crossings. Let us know about access, parking and anything unusual about getting there when you book.
When is the sealant fully cured?
It depends on the product and the conditions. We tell you how long to leave it before we go.
Should I point up the gap in my brickwork?
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.
What sealant do you use?
The product depends on the job: sanitary silicone where it gets wet, and sealants suited to movement or weather elsewhere. We use products from Arbo and Everbuild.
Is it worth trying it myself?
Some simple jobs can be done by a careful DIYer. Most DIY failures come from sealing over old material, wet joints or too much sealant.
Can you seal joints between render and window frames?
Yes. Materials like render, brick, metal and uPVC all move differently, so a flexible sealant is needed where they meet. We choose one that suits both surfaces.
Can landlords and businesses book you?
Yes. We work in homes, commercial premises and hotels, and we are fully insured.
How we quote for external mastic
We don’t publish a price list. What we look at:
- Any mould that needs treating
- The type of sealant required
- Whether the work is at height
- The number and length of the joints
The cost depends on how much there is to do, how hard the old material is to remove and access to the work. You’ll have a clear quote before any work starts, so you know where you stand.
What we need to know
A few details help us give you an accurate quote. When you get in contact, it helps to mention:
- How we’d reach the joints
- Where the job is, and your postcode
- How many joints, rooms or windows are involved
- What the problem is, such as mould, gaps, leaks or cracking
We quote each job on its own, so start by telling us what you need. Just send an email to info@mrmastic.co.uk with the details, and photos are welcome.
What we cannot put right
A few problems are outside what sealant work can do:
- Walls that need new movement joints cut into them
- Cracking across the wall rather than at a joint
- Rising or penetrating damp from elsewhere in the wall
Not sure which it is? You can email us at info@mrmastic.co.uk and we’ll tell you honestly before booking.
Joints and surfaces we work on
- Render & cladding joints
- Joints between brick and frames
- Concrete & block
- Copings & trims
- Façade panels
- Brickwork movement joints
What else we do in Haroldswick
Common problems we fix in Haroldswick
UV, rain and frost all age exterior sealant. Over the years it hardens, cracks on the surface and loses its give, so the joint eventually tears or comes away from one side.
The most common problems we see are:
- Joints pointed up with cement by mistake
- Hard, crazed mastic that has stopped moving
- Weeds or debris growing in open joints
- Movement joints with cracked, split or missing sealant
Homes close to St John's Church include some older properties, and older walls, gutters and the joints where extensions meet them need a flexible sealant.
What to look for in a quote
- Which colour the sealant will be
- How much experience the applicator has
- What guarantee comes with the work
- How long to leave it before use
DIY sealant or a professional job?
A DIY attempt does not rule out a professional job. We remove it and do the joint properly, so just mention it when you contact us.
What a professional job adds is preparation and the right product. Joints are cleaned back to sound surfaces and dried, and the sealant is chosen for how the joint moves and where it is, then guaranteed for a year.
Why deal with it now?
Low-modulus sealants stretch easily, so they put less strain on the joint edges. That matters on brick, render and concrete, which can be weaker at the face. A stiffer product can damage the joint edge as it fails. Out of town in Scotland, exposed walls take a lot of weather, and damp in stone or harled walls takes a long time to dry once water gets behind a joint.
Instead of a standard rate, we price the job in front of us: the amount of work, the old material and the access. You will know the price before we begin.
Why book with us
- Quality sealants from Arbo and Everbuild
- More than 20 years in sealant work
- Rated 4.9 stars on Google
- White, clear, grey or coloured to suit, where the product allows
Read our cost guide or customer reviews.