Shetland Islands · Scotland
External Mastic in Gunnista
External mastic across Gunnista and nearby, with old sealant always removed completely and a one-year guarantee.
- Damp patches traced to an open external joint
- Old sealant gone brittle and cracked
- Joints pointed up with cement by mistake
What affects the quote in Gunnista
Some jobs are bigger than they look, and some smaller. The main factors:
- Mould in or behind the old joints
- The number and length of the joints
- The old material and how stubborn it is
- Whether the work is at height
Leaving a failed joint normally makes the job bigger, not smaller, because water and mould keep working on it. If you’re unsure, email us at info@mrmastic.co.uk and we will give you an honest view and a quote.
What to tell us for a quote
When you contact us, these details help:
- Whether it has been sealed before
- Whether it’s a home or a business
- Photos by email, if that is easy
- How we’d reach the joints
There’s no standard price list, as no two jobs are quite the same. Instead, we give you a clear quote for your job. To arrange one, email us at info@mrmastic.co.uk.
About our external mastic in Gunnista
Many failed façade joints only get noticed once there’s a stain or a damp patch inside. We inspect them, agree which need doing and reseal with a weatherproof, flexible sealant. If you have plants rooting in failed movement joints and cracked joints where brick meets render or frames, we can help, on copings & trims, brickwork movement joints and render & cladding joints alike.
Outside joints can only be sealed when they’re dry, so work in Gunnista depends on the weather, and longer journeys are planned in advance. Tell us how to reach each wall, gutter and roofline.
There’s a 12-month guarantee on every job, whatever its size.
- Location
- Gunnista (ZE2)
- Region
- Shetland Islands
- Guarantee
- A year, on every job
- Price
- Quoted before any work starts
- info@mrmastic.co.uk
- Last updated
- 26 October 2026
Keeping the joints in good condition
Once the sealant has cured, a few habits help it last:
- Ask before painting over external sealant
- Check external joints each spring
- Avoid pressure-washing directly into sealant joints
- Clear growth from the base of walls and joints
Avoid pressure-washing straight into the joints. A strong jet can damage the edges of the bead over time.
Small splits are the time to act. At that stage it’s a simple cut out and reseal before water has had years to get in.
Gunnista questions
Is Gunnista within the area you cover?
Yes. Gunnista is within the area we cover, which takes in towns, villages and rural addresses. Our work covers the whole 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.
Is Gunnista in your area for external mastic?
Yes, Gunnista is within the area we cover. We work across all of Scotland. You can send an email to info@mrmastic.co.uk and tell us what needs doing.
Is it OK to seal over old sealant?
No, it won’t last. It can look neat for a few weeks, but the new bead soon lifts. Removing the old sealant completely is the only lasting way.
Is the work guaranteed?
Yes. Each job is guaranteed for twelve months, large or small.
What colours does the sealant come in?
The aim is a neat, even joint in a colour that suits the wall. We will talk through colour options before work begins, matched as closely as the range allows.
What do you need from me for a quote?
A short description and the location, plus pictures if you have them. If we need more, we will ask.
How long before the joint can be used?
Most sealants are touch-dry well before they’re fully cured. We’ll tell you how long to leave the joint.
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 are using.
Other services in Gunnista
How it works
We keep the work tidy and contained to the area we’re working on, so you can carry on as normal. Expect the work to take a few hours for a handful of joints, longer for a whole elevation, and we explain the cure time before we leave. Outside jobs in Gunnista need a dry day, because sealant will not bond to a wet joint, so external jobs may need to move if the day turns wet. Indoor work goes ahead whatever the weather.
- First we look over the joints with you, agree which to renew and talk through access.
- 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.
- We gun in a flexible exterior sealant in a colour that suits the wall and tool it neatly.
How to prepare
- For indoor joints, keep the area dry beforehand if you can
- Mention if the joints have been sealed before
- Let us know about parking restrictions
Getting a quote
It all starts with a short chat. Tell us what’s wrong, where it is and how much there is, and we will talk you through what we’d do. When it suits you, drop us a line at info@mrmastic.co.uk.
Read more
Can I do it myself?
Sealing over old silicone is the commonest DIY error. Silicone does not stick to old silicone, so it peels away and traps moisture behind it. Everything old must be removed first.
Too much sealant is as bad as too little. A thick, smeared bead looks untidy and does not move well, and the joint depth matters as much as the finish.
Walls and rooflines in Gunnista
Gunnista is close to the coast, where wind-driven rain is a fact of life and, nearer the shore, so is salt air. That’s hard on movement joints and outside wall joints, especially on the side facing the sea. On the islands, wind and salt spray are hard on outside sealant.
For an older house near a landmark such as St Ola's Church and burial-ground, old and new materials meet at the roofline and walls, which is where sealant earns its keep.
Gunnista is in the Shetland Islands. Homes, rented property, offices and hotels in Gunnista can book us for external mastic. Every job comes with our one-year guarantee. Our the Shetland Islands coverage runs to 63 places, Gunnista among them.
Work in ZE2 is quoted and booked the same way as anywhere else. Other places close to Gunnista include Heogan (1 mile west), Gremista (2 miles west), Grindiscol (2 miles south), Lerwick (2 miles south-west) and Sound (3 miles south-west). If you are somewhere remote, a little more planning is needed.
Landmarks near Gunnista
Well-known places in the area include Shetland Museum (2 miles south-west) and Montfield Hospital (2.2 miles south-west). Green spaces nearby include Loch of Aith.
Landlords, agents and businesses in Gunnista
Hotels need rooms back in use, so we plan the work room by room. We have worked in hotels as well as homes and businesses.
If you manage several properties in or around Gunnista, several properties can go on one quote. Send us the addresses and the work at each, and photos by email help.
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. Too stiff a sealant can pull at the edges and break them. Exposed walls in smaller Scottish places take a lot of wind and rain, and once water gets behind a failed joint, damp in stone or harled walls is slow to dry out.
What you pay reflects the work, not a rough estimate. That’s why we ask a few questions first.
Why Gunnista customers choose us
- A 12-month guarantee on all work
- Sanitary silicone with an anti-fungal additive in wet areas
- Tidy, careful work
- Old sealant always removed completely
See our cost guide and what customers say.
Signs you need external mastic in Gunnista
Some movement joints have been pointed up with mortar. With the joint locked solid, the movement turns into cracks elsewhere in the wall.
Most people get in touch after spotting one of these:
- Brick movement joints where the sealant has split
- Rigid filler in a joint that should flex
- Old sealant gone brittle and cracked
- Damp patches traced to an open external joint
If you look after a building such as Anderson High School, its movement joints, gutters and trims need looking after like any other building’s.
Before you book anyone
- Whether the sealant suits the joint
- Is the old sealant removed completely?
- How the surfaces are prepared before sealing
- Whether they’re fully insured