Na h-Eileanan Siar · Scotland
Crosbost External Mastic
Sealing brickwork movement joints, render, cladding and façade joints for householders, landlords and businesses in Crosbost. ARBOMaster approved applicators, fully insured, with a 12-month guarantee.
- Plants rooting in failed movement joints
- Brick movement joints where the sealant has split
- Panel joints letting water in
Common problems we fix in Crosbost
Buildings move more than people expect. Brickwork grows a little over the years, blockwork and concrete shrink, and all of it moves with heat and moisture. The sealant in the movement joints takes that strain.
People normally contact us when they notice something like this:
- Sealant pulling away from one side of the joint
- Brick movement joints where the sealant has split
- Hard, crazed mastic that has stopped moving
- Cracked joints where brick meets render or frames
For jobs in and around Crosbost, choosing the right material for each joint is as important as a tidy finish.
Questions to ask before booking
- Which sealant they’ll use, and why
- How long the guarantee is
- Whether VAT is included
- What happens if they find a problem under the old sealant
External mastic in Crosbost, done properly
Short cuts in external joints show up within a season or two. Overfilled joints, missing backing rod and sealant laid over old sealant all tend to fail early. We strip the joint back and start again. We work on brickwork movement joints, joints between brick and frames and concrete & block, and common reasons people get in touch are joints where the bead has come unstuck and joints with sealant missing in places.
Stone walls need a stone-friendly sealant, as acetoxy products can attack some stone. On newer homes, the movement joints and roofline trims are what need watching.
A one-year guarantee comes as standard, so you are covered after we’ve gone.
- Place
- Crosbost (HS2)
- Wider area
- Na h-Eileanan Siar
- Cover
- A year, on every job
- Quote
- Quoted before any work starts
- info@mrmastic.co.uk
- Updated
- 26 October 2026
Landlords, agents and businesses in Crosbost
Businesses can book us for washrooms, kitchens, offices and more. For commercial premises, we can talk through working times when we quote.
In hotels, rooms out of use cost money, so we plan the work room by room around your bookings where we can. Hotel work is part of what we do, alongside homes and businesses.
Questions from Crosbost
Do you cover Crosbost for external mastic?
Yes, Crosbost is within the area we cover. Our work covers the whole of Scotland. You can email us at info@mrmastic.co.uk and tell us what needs doing, and we’ll give you a clear price.
Do you cover smaller places like Crosbost?
Yes. Crosbost 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. Just mention lanes, gates or anything else about the route when you book.
What is a movement joint?
Most straight vertical gaps in brickwork are movement joints. It lets the bricks expand without cracking, and it should be sealed with a flexible sealant.
What colours does the sealant come in?
We choose a sealant colour to suit the brick, stone or render so the joint blends in. Exterior sealants come in a good range of colours.
Is it messy?
We keep the work tidy. Nearby surfaces are protected, and the area is left clean when we finish.
I rent my home. Can I book you?
Of course. Ask your landlord first, and we can send them the quote if that helps.
Do you work for hotels and businesses?
Yes. Larger jobs can be planned room by room or area by area to suit the site.
Can a movement joint be filled with mortar?
No. Cement or mortar can’t stretch and the joint fails. Where a joint has been mortared, it can often be raked out and sealed properly.
What happens on the day
Most of a good job is in the preparation, and we don’t rush it. Every joint is cleaned and dried before new material goes in. All told, the work takes a few hours for a handful of joints, longer for a whole elevation. In smaller Scottish places, parking is usually less of an issue than access and distance. Tell us how to find the property and how to reach the work, and the visit is planned around that.
- 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.
- The faces are brushed clean and primed where the product requires it.
- Backing rod sized to the joint goes in to set the depth.
- The exterior sealant is applied, tooled and checked along its length.
Getting ready for the visit
- Let us know about stairs, lifts or work at height
- Mention any sign-in or site rules at work premises
- Mention any leaks or damp you’ve noticed
Ask for a quote
A good description makes for an accurate quote. Let us know the location, the problem and roughly how many joints, and email pictures if that is easy.
Advice
What affects the quote in Crosbost
The quote reflects the job in front of us. We look at:
- How easy the joints are to reach
- How much old sealant there is and how hard it is to remove
- Which sealant suits the joint
- The number and length of the joints
Leaving a failed joint generally makes the job bigger, not smaller, because water and mould keep working on it. If you are unsure, drop us a line at info@mrmastic.co.uk for an honest opinion and a quote.
What to tell us for a quote
The more you tell us, the more accurate the quote. When you ask for a quote, tell us:
- Pictures of the joints, sent by email
- Whether it’s a home or a business
- Any access issues, like height or stairs
- The address or postcode of the job
Quotes start with a quick conversation. Describe the problem, the location and the size of the job, and we’ll talk you through what we’d do. When it suits you, email us at info@mrmastic.co.uk.
What external mastic looks like in Crosbost
Crosbost is within about 1 mile of the coast, and homes near the sea take more wind-driven rain, with salt in the air closer to the shore. Both are hard on movement joints and outside wall joints, which can dry out and crack sooner where a building faces the weather. The west of Scotland is wetter than the east, which means movement joints and outside wall joints has to cope with a lot of rain.
Around Crosbost, as everywhere, external mastic is only as good as the preparation behind it.
Crosbost is in Na h-Eileanan Siar. Homes, rented property, offices and hotels in Crosbost can book us for external mastic. Every job comes with our 12-month guarantee. Across Na h-Eileanan Siar, we cover 87 places, and Crosbost is one of them.
We work across HS2 for external mastic and the streets around it. Nearby, we also carry out external mastic in North Lochs (1 mile west), Liurbost (1 mile west), Lacasaidh (4 miles south-west), Sandwick (5 miles north-east) and Stornoway (5 miles north). For island and remote addresses, a little more planning is needed, so mention it when you ask for a quote.
Local landmarks in Crosbost
Well-known places in the area include Western Isles Hospital (5.9 miles north). For a walk, there’s Loch na Craoibhe and Nisreaval.
How to look after the new joints
Once the sealant has cured, a few habits help it last:
- Walk round the building once a year and look at the joints
- Make sure movement joints are not pointed over
- Tell anyone working on the walls about the movement joints
- Keep water from gutters off the wall
Avoid pressure-washing straight into the joints. High-pressure water can lift the edges over time.
Leave a failed movement joint and water keeps getting into the wall. That can lead to damp patches, staining and frost damage which cost more to put right than the joint.
Why it’s worth doing now in Crosbost
Water gets in through a failed movement joint and can run behind render or cladding. Resealing early keeps the job to the joint itself, instead of the wall and finishes around it. In an older home around Crosbost, damp from a failed joint can get into timber and plaster, which is a far bigger job than the sealant.
We don’t show prices on the website, because the cost depends so much on the job itself. For a quick quote, please send an email to info@mrmastic.co.uk and we’ll talk you through it.
What you get with us
- White, clear, grey or coloured to suit, where the product allows
- ARBOMaster approved applicator
- Experience in homes, commercial sites and hotels
- Old sealant always removed completely
Different surfaces, different methods
Copings and trims
Coping and trim joints face rain and sun head on. Each is resealed with a weatherproof, flexible sealant.
Render joints
Rendered walls have joints at beads, openings and changes of material. They’re resealed in a sealant that suits the render.