Orkney Islands · Scotland
External Mastic in Grimbister
External mastic for Grimbister, by sealant specialists with 20+ years’ experience. 180+ five-star Google reviews and a 4.9 rating.
- Old sealant gone brittle and cracked
- Failed seals between different materials
- Plants rooting in failed movement joints
Signs you need external mastic in Grimbister
Some movement joints have been pointed up with mortar, often by someone who didn’t know what it was for. With the joint locked solid, the movement turns into cracks elsewhere in the wall.
Keep an eye out for any of the following:
- Panel joints letting water in
- Water getting into walls through failed joints
- Joints with sealant missing in places
- Old sealant gone brittle and cracked
For jobs in and around Grimbister, choosing the right material for each joint is as important as a tidy finish.
What your quote should include
- Who does the work, and how experienced they are
- What happens if they find a problem under the old sealant
- Whether they’re fully insured
- Which sealant they’ll use, and why
How we handle external mastic in Grimbister
Getting the depth right is half the job. Closed-cell backing rod sets the depth and stops the sealant sticking to the back, so it bonds to the two sides only and can stretch. We are often asked to deal with panel joints letting water in and cracked joints where brick meets render or frames, across façade panels, copings & trims and render & cladding joints.
Across smaller places in Scotland, stone and harled cottages, farm buildings and newer houses often stand exposed to wind and rain. Outside joints on exposed walls work hard.
We stand behind the work with a one-year guarantee, so you are not left on your own once the job is done.
- Where
- Grimbister (KW15)
- Region
- Orkney Islands
- Cover
- 12 months on all our work
- Price
- A clear quote up front
- info@mrmastic.co.uk
- Updated
- 26 October 2026
What the job involves on each surface
Joints between dissimilar materials
Brick against render, concrete against metal, stone against timber: every change of material is a joint. A flexible sealant bridges the two so neither cracks the other.
Copings and trims
Coping and trim joints face rain and sun head on. We reseal them with an exterior sealant suited to the material.
Grimbister buildings and the weather
Grimbister is within about 1 mile of the coast, where wind-driven rain is a fact of life and, nearer the shore, so is salt air. Both are hard on movement joints and outside wall joints, which can dry out and crack sooner where a building faces the weather. Under the Repairing Standard, private landlords in Scotland have to keep homes wind and watertight, and sound outside sealant is part of that.
In and around Grimbister, as anywhere, good external mastic starts with a clean, dry, properly prepared joint.
Grimbister is about 5 miles west of Kirkwall, in the Orkney Islands. From the centre of Grimbister to the outskirts, we cover external mastic for every kind of property, from flats and houses to offices and hotels. Grimbister is one of 51 towns and villages in the Orkney Islands we cover for external mastic.
Our applicators cover all of KW15 for external mastic. We also cover the places around Grimbister: Finstown (1 mile north-west), Heddle (1 mile west), Germiston (2 miles south-west), Kirbister (4 miles south) and Norseman (4 miles north). If you are somewhere remote, a little more planning is needed.
Around Grimbister
Nearby you will also find Balfour Hospital (4.9 miles east) and Kirkwall Castle (4.9 miles east). Not far away are Loch of Wasdale and Hill of Heddle.
What sealant work can’t fix
In fairness, there are a few things sealant won’t fix:
- Adding movement joints to masonry that has none
- Subsidence or other structural problems
- Cracks in the bricks or render themselves, away from the joints
If you are not sure, just drop us a line at info@mrmastic.co.uk and we will give you a straight answer before you book.
Where we work in Grimbister
- Joints between brick and frames
- Concrete & block
- Render & cladding joints
- Copings & trims
- Brickwork movement joints
- Façade panels
Grimbister questions
Do you cover smaller places like Grimbister?
Yes. Grimbister 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.
Does living near the coast affect external mastic in Grimbister?
Near the sea, outside joints face more wind, rain and salt than they would inland, so the choice of sealant and the preparation matter even more. Walls facing the sea are generally the first to need attention.
Should I try DIY first?
For a simple, easy-to-reach joint, a careful DIYer can do a reasonable job. The usual mistakes are sealing over old sealant, sealing a damp joint and using too much.
How long does external mastic last?
That depends on the wall, the weather and the movement. Look for splits, hardening or edges coming away and have them redone then.
What is a movement joint?
A movement joint is a planned break in the wall that absorbs expansion and shrinkage. It’s sealed with a flexible sealant, not mortar.
What sealant do you use?
Quality sealants from brands including Arbo and Everbuild, picked for each joint. We explain the product when we quote.
What should I tell you?
A short description and the location. We’ll ask anything else we need to know.
Is there any odour?
That depends on the sealant. Some products have a noticeable smell, others very little.
Looking after it afterwards
Once the sealant has cured, a few habits help it last:
- Ask before painting over external sealant
- Get split or bare joints resealed while the damage is small
- Wash walls gently around the sealant
- Deal with leaking gutters that soak the joints below
Look over the joints once a year, ideally after winter. Watch for splits, edges coming away or growth in the joint.
An open movement joint lets rain into the wall every time it pours. Over time it can mean damp inside, stained render or frost-damaged brick, all bigger jobs than a reseal.
More services for Grimbister
Work for landlords, hotels and businesses
In hotels, rooms out of use cost money, so we plan the work room by room. We have worked in hotels as well as homes and businesses.
For anyone letting property in or around Grimbister, jobs at different addresses can go on one quote. Just tell us the addresses and what each one needs.
DIY versus a professional finish
The biggest DIY mistake is sealing over old sealant. Silicone doesn’t stick to old silicone, so it lifts and traps water and mould underneath. Everything old must be removed first.
Some sealant jobs are within reach of a careful DIYer, like a short, easy-to-reach joint indoors. The common mistakes are sealing over old sealant, sealing a damp joint and using far too much.
How the visit works
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 starts. The work usually takes a few hours to a few days, depending on the length of joint and the access. Outside jobs in Grimbister need a dry day, because sealant will not bond to a wet joint, so an outdoor job can move if the forecast changes. Work indoors isn’t affected.
- We start by walking round the building and agreeing the joints and the access.
- Every bit of old sealant and any mortar or debris is cut out.
- Joint faces are cleaned back and primed if the sealant needs it.
- We fit closed-cell backing rod to control the depth.
- We apply the sealant, tool it and check the whole run.
Preparing for the visit
- Where the joints are inside, avoid wetting them before we arrive
- For business premises, tell us about site rules or sign-in
- Mention any leaks or damp you’ve noticed
How to get a quote
For a quote, email us at info@mrmastic.co.uk with the location and a short description of the problem. We will send you a clear quote before any work starts.