Na h-Eileanan Siar · Scotland
Crosbost Window Mastic
Problem with your window and door frames in Crosbost? We remove the old material, prepare the joints and seal them properly, and the work is guaranteed for a year.
- Draughty joints inside around the window
- Whistling draughts around closed windows
- Sealant in the wrong colour for the frame
About our window mastic in Crosbost
Behind a thin line of old mastic there’s sometimes a deep void. Filling it with sealant alone leaves a joint that cannot move properly, so we fit backing rod to set the right depth. That way the new bead bonds to the frame and the wall only. If you’re dealing with cracked or shrunken mastic around the frame and rushed sealant from a window installation, we can put it right, whatever the surface.
Many older Scottish homes still have timber windows set into stone walls. The sealant has to suit the stone, which rules out acetoxy silicones that can mark or attack it.
You are covered for a year from the day we finish. If there’s a problem with it, please send an email to info@mrmastic.co.uk.
- Location
- Crosbost (HS2)
- Wider area
- Na h-Eileanan Siar
- Guarantee
- 12 months on all our work
- Quotes
- A clear quote up front
- info@mrmastic.co.uk
- Updated
- 26 October 2026
Crosbost questions
Does the coastal weather in Crosbost affect outside sealant?
Coastal homes put outside sealant through more weather than inland ones, so preparation and the right sealant matter all the more. It’s worth checking the walls that face the sea first.
Is Crosbost in your area for window mastic?
Yes. We work across all of Scotland, and Crosbost is part of that. Just send an email to info@mrmastic.co.uk with a few details of the job.
Do you hold any approvals?
Yes. ARBOMaster is the approved applicator scheme for Arbo sealants, and we are part of it.
Can you work on commercial sites?
Yes. We’ve worked for hotels, offices and other businesses.
Where is Mr Mastic based?
We work from Crawley. We cover Crosbost and the rest of Na h-Eileanan Siar.
What do you need from me for a quote?
The location, the problem and the rough size of the job. If you can, email a few photos.
Can new window sealant be painted?
It depends on the sealant. Silicone is not paintable, but some hybrid sealants are. Mention any painting plans before any work starts.
Will the old sealant be removed?
Yes, every time. New sealant won’t bond properly to old, so the joint is cleaned back first.
Other services in Crosbost
Common problems we fix in Crosbost
Water runs down the glass onto the sill, so the sill ends and the joint below the frame are common leak points. Failed sealant there lets rain into the wall or behind the frame.
The most common problems we see are:
- Gaps left after new windows were fitted
- Damp patches on the reveal after heavy rain
- Sealant in the wrong colour for the frame
- Mastic that has split away from the wall
In and around Crosbost, as anywhere, good window mastic starts with a clean, dry, properly prepared joint.
Before you book anyone
- Which colour the sealant will be
- Are they insured?
- How the surfaces are prepared before sealing
- What the quote includes, VAT included or not
Can I do it myself?
Sealing over old silicone is the commonest DIY error. Silicone does not stick to old silicone, so it lifts and traps water and mould underneath. All the old material has to come out first.
If you are set on DIY, put the effort into preparation: remove every trace of old sealant, clean and dry the joint, and follow the product’s cure time. If it fails, we can still redo it.
What we do, step by step
A visit follows a simple pattern: we look at the joints together, mask and protect the surrounding surfaces, carry out the job and clear up. Most jobs take a few hours for a handful of frames, longer for a whole house. Somewhere like Crosbost may be a longer drive, and the journey is planned ahead. Mention tracks, gates, ferries or anything else about the route.
- We start by checking each window and door with you.
- The old mastic is cut out and the surfaces cleaned back.
- We fit backing rod in deep gaps so the sealant is the right depth.
- New exterior sealant goes on in a matching colour and is tooled smooth.
- Every joint is checked before we leave.
Preparing for the visit
- Try not to wet indoor joints just before the visit
- Mention any tricky access
- Keep pets and children clear of the area while we work
Ask for a quote
It all starts with a short chat. Describe the problem, the location and the size of the job. Whenever you are ready, send an email to info@mrmastic.co.uk.
Read more
How the job changes by surface
Patio & French doors
Patio and French doors have the longest joints on most houses. The threshold and the bottom corners take the most water, so they get particular care.
uPVC windows
The frame is cleaned with a product that will not harm the plastic, then the sealant goes in between frame and wall.
How we quote for window mastic
We quote each job individually. These are the things that affect it:
- Which sealant suits the joint
- Mould in or behind the old joints
- When we can work, for business premises
- How easy the joints are to reach
The cost reflects the work involved, not a rough estimate. That’s why we ask a few questions first.
Helping us quote
Photos by email are helpful but not essential. Please mention:
- What’s wrong with the joints now
- Where the job is, and your postcode
- Any previous sealing or DIY work
- Pictures of the joints, sent by email
Every job is quoted individually. Just drop us a line at info@mrmastic.co.uk with the details.
Leave it or put it right?
Draughts and leaks do not always mean new windows. Where the frames are sound, new mastic generally deals with draughts and leaks at the edges. If we find failed glass units or worn seals, we’ll tell you. 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.
Rather than a set price list, we price the job in front of us: how many joints, what’s in them now and how we reach them. The price is agreed before we begin.
Why book with us
- Any old sealant cut out fully, not covered over
- A sealant colour to suit the surroundings
- Over 20 years’ experience
- An ARBOMaster approved applicator
For landlords and businesses
For anyone letting property in or around Crosbost, jobs at different addresses can go on one quote. Just tell us the addresses and what each one needs.
Mouldy or split sealant often shows up at the end of a tenancy, and it’s quick to put right between tenancies. We can quote for more than one property at once.
Frames and glazing around Crosbost
Crosbost is close to the coast, where wind-driven rain is a fact of life and, nearer the shore, so is salt air. That is hard on the mastic around window and door frames, especially on the side facing the sea. Sash and case windows are common in older Scottish homes, often pointed into the wall with traditional sand mastic.
For jobs in and around Crosbost, choosing the right material for each joint is as important as a tidy finish.
Crosbost is in Na h-Eileanan Siar. Jobs in Crosbost get the same care as everywhere else we work: the old material taken out, joints prepared properly and a 12-month guarantee. Crosbost is one of 87 places in Na h-Eileanan Siar where we work for window mastic.
Here we cover the HS2 postcode area for window mastic. Neighbouring places we cover for window mastic include North Lochs (1 mile west), Liurbost (1 mile west), Lacasaidh (4 miles south-west), Sandwick (5 miles north-east) and Stornoway (5 miles north). Island and remote addresses take a little more planning, so tell us where you are when you ask for a quote.
Around Crosbost
A little further out are Western Isles Hospital (5.9 miles north). For a walk, there’s Loch na Craoibhe and Nisreaval.