Na h-Eileanan Siar · Scotland
External Mastic in North Lochs
Sealing brickwork movement joints, render, cladding and façade joints in North Lochs, with a one-year guarantee on every job. Ask us for a quote.
- Cracked joints where brick meets render or frames
- Moss and dirt in joints with no sealant left
- Sealant that has lost its bond to the brick or render
Keeping the joints in good condition
Good habits help new joints last longer. A few tips:
- Ask before painting over external sealant
- Never let anyone fill a movement joint with mortar
- Check external joints each spring
- Keep high-pressure jets off the joints
Don’t paint over the new sealant unless we have said the product is paintable. Many exterior sealants aren’t designed to be painted, and paint can crack as the joint moves.
Once a joint can’t move, the wall finds another way, usually as cracking in the brickwork or render nearby. Resealing it early helps prevent that.
External mastic in North Lochs
For buildings in North Lochs, we reseal external joints of all kinds, from brick movement joints to cladding panels. The preparation is the same whatever the wall: clean, sound faces and a controlled depth. Typical jobs include damp patches traced to an open external joint and failed sealant between panels on a façade, across render & cladding joints, façade panels and joints between brick and frames.
Older stone buildings need a sealant that suits the stone, not an acetoxy product that can mark or attack it. Newer houses need their movement joints and roofline trims kept sound.
We stand behind the work with a one-year guarantee.
- Where
- North Lochs (HS2)
- Region
- Na h-Eileanan Siar
- Guarantee
- A year, on every job
- Quote
- Quoted before any work starts
- info@mrmastic.co.uk
- Last updated
- 26 October 2026
Leave it or put it right?
Running new sealant over the old bead rarely lasts. New sealant does not bond well to old, weathered sealant, so the old joint is cut out fully first. In an older home around North Lochs, damp from a failed joint can get into timber and plaster, which is a far bigger job than the sealant.
Combining jobs into one visit is generally more efficient than separate visits. We will send you a clear quote for the lot.
Why us?
- White, clear, grey or another colour, product permitting
- Quality sealants from Arbo and Everbuild
- We leave the area clean and tidy
- 180+ five-star Google reviews
See our cost guide and our reviews.
DIY sealant or a professional job?
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.
Overfilling a joint is a classic DIY mistake. A thick, smeared bead looks untidy and doesn’t move well, and the joint depth matters as much as the finish.
Work for landlords, hotels and businesses
If you manage several properties in or around North Lochs, jobs at different addresses can be quoted together. Send us the addresses and the work at each, and photos by email help.
Letting agents often deal with us directly. Tell us the address, the job and how access works and we will quote.
More services for North Lochs
What the job involves on each surface
Joints between dissimilar materials
Wherever two materials meet, they move differently. A flexible sealant bridges the two.
Concrete and blockwork
Wide joints in concrete need the depth controlling carefully. Backing rod sized to the joint sets it.
What external mastic looks like in North Lochs
North Lochs 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. That is hard on movement joints and outside wall joints, especially on the side facing the sea. 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 North Lochs, as anywhere, good external mastic starts with a clean, dry, properly prepared joint.
North Lochs is about 6 miles south-west of Stornoway, in Na h-Eileanan Siar. Every kind of property in North Lochs can book us for external mastic. The work is guaranteed for a year. Our Na h-Eileanan Siar coverage runs to 87 places, North Lochs among them.
Work in HS2 works the same way as everywhere else we cover. We also cover the places around North Lochs: Crosbost (1 mile east), Liurbost (1 mile west), Lacasaidh (4 miles south-west), Marybank (5 miles north) and Stornoway (6 miles north-east). Island and remote addresses take a little more planning, so please mention your location when you drop us a line at info@mrmastic.co.uk.
Local landmarks in North Lochs
A little further out are Western Isles Hospital (6 miles north-east). Not far away are Nisreaval and Loch na Craoibhe.
North Lochs questions
Is North Lochs in your area for external mastic?
Yes. Our work covers the whole of Scotland, and North Lochs is part of that. You can drop us a line at info@mrmastic.co.uk and let us know what needs doing.
Do you cover smaller places like North Lochs?
Yes. North Lochs 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. Just mention lanes, gates or anything else about the route when you book.
How much does external mastic cost in North Lochs?
The cost depends on the size of the job, access and how much old sealant has to come out. Call for a quick quote.
Will there be a smell?
There can be a smell while the sealant cures. Opening a window helps.
Is it OK to fill a movement joint with cement?
No. Rigid materials can’t move with the wall, so the joint stops doing its job. Where a joint has been mortared, it can often be raked out and sealed properly.
Can tenants book the work?
Of course. Ask your landlord first, and we can send them the quote if that helps.
Do you hold any approvals?
Yes. We are ARBOMaster approved, the scheme for applicators of Arbo sealants.
What should I tell you?
Where the job is, what the problem is and roughly how big it is. Photos by email help too.
What we are called out for in North Lochs
UV, rain and frost all age exterior sealant. In time it goes hard, crazes on the surface and stops stretching, so the joint eventually tears or comes away from one side.
It’s worth asking for a quote if you see:
- Panel joints letting water in
- Joints pointed up with cement by mistake
- Gaps where render, brick and frames meet
- Sealant that has lost its bond to the brick or render
For an older house near a landmark such as Parish Church, an extension built onto an older house moves differently, and the joint between them takes the strain.
Questions to ask before booking
- Which colour the sealant will be
- Are they insured?
- Is the old sealant removed completely?
- Which sealant they’ll use, and why
What we do, step by step
At the end, we look at the finished work together. The visit itself normally takes a few hours to a few days, depending on the length of joint and the access, depending on the amount of work. Around North Lochs, distance and access matter more than parking. Tell us how to find the property and how to reach the work.
- 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.
- We fit closed-cell backing rod to control the depth.
- We apply the sealant, tool it and check the whole run.
Before we arrive
- Keep pets and children clear of the area while we work
- For indoor joints, keep the area dry beforehand if you can
- 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’ll give you a clear price before any work starts.