Na h-Eileanan Siar · Scotland
Window & door mastic in Knock, Na h-Eileanan Siar
We cover Knock for mastic around window and door frames, sills and patio doors. Old sealant removed completely, joints prepared properly.
- Mastic that is falling out in pieces
- Damp patches on the reveal after heavy rain
- Whistling draughts around closed windows
Window mastic in Knock
Mr Mastic’s applicators have more than 20 years’ experience with window and door sealants. We are fully insured ARBOMaster approved applicators, and we give a 12-month guarantee on the work. If you have cracked internal joints between frame and plaster and untidy mastic left by window fitters, we can put it right, whatever the surface.
Across smaller places in Scotland, homes range from stone and harled cottages to newer houses, many standing in the open. Exposed frames and sills take the full force of wind-driven rain, so the mastic there works hard.
All our work is covered by our 12-month guarantee.
- Where
- Knock (HS2)
- Wider area
- Na h-Eileanan Siar
- Cover
- 12 months on all our work
- Quotes
- A clear quote up front
- info@mrmastic.co.uk
- Updated
- 26 October 2026
Landlord and commercial work in Knock
Failed sealant is one of the commonest items on a check-out report. Several properties can be quoted together.
From a single let to a portfolio, you get the same standard of work: old sealant fully removed, joints prepared properly and a one-year guarantee.
More services for Knock
Knock: your questions answered
Is Knock within the area you cover?
Yes, we do. We work across all of Scotland, islands included, from towns to the smallest places. The journey is planned ahead, so it helps to know about access.
Is window mastic in a coastal place like Knock any different?
Coastal weather is harder on outside sealant: there’s more wind-driven rain and, closer to the shore, salt in the air. The right product, a clean joint and the right depth all help it cope.
Will it make a mess?
Very little: the area around the joints is protected first, and we tidy up before we go.
Will resealing my frames help with draughts?
In many cases. The gap between frame and wall is a common source of draughts, and resealing inside and out closes it.
Can you get sealant to suit coloured frames?
Yes, we choose a colour to suit the frame. Grey and black frames get grey or black sealant, and wood-effect frames usually suit brown.
Do you do commercial work?
Yes, regularly. Larger jobs can be planned room by room or area by area.
Should I try DIY first?
That depends on the joint. High-level, external movement and fire-rated joints are professional jobs.
Can you seal over the old sealant?
No, it won’t last. It may look fine at first, but the new layer lifts away from the old one. The old sealant has to come out completely.
Can I do it myself?
What a professional job adds is preparation and the right product. We take joints back to clean, dry surfaces, and the sealant is chosen for how the joint moves and where it is.
A careful DIYer can reseal a simple joint, like a short, easy-to-reach joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
When something else is needed
Before you book, it’s worth knowing the limits too:
- Soft or decayed wood in the frame
- Condensation trapped between the panes
- A sash or casement that will not close properly
If you’re not sure, just email us at info@mrmastic.co.uk and we will give you a straight answer.
Joints and surfaces we work on
- Window sills
- Composite doors
- Timber windows & doors
- Aluminium frames
- uPVC windows
- Patio & French doors
Looking after it afterwards
Aftercare is simple, and it makes a real difference:
- Walk round the house once a year and look at the joints
- Keep paint and stain on wooden frames in good order
- Do not paint over the silicone
- Don’t aim a pressure washer at the joints
Keep the new mastic undisturbed while it cures, following the cure time we give you. Keep jet washers away from the frames.
On timber windows, water behind the joint can lead to rot. Once wood has rotted, it needs repair before it can be sealed, so it pays to reseal before that happens.
What happens on the day
All our tools and materials come with us in the van, so there’s nothing for you to buy. After a quick look at the joints together, the area is protected and the work begins. Most jobs take most of a day for a typical house, less for a few frames. Outdoor work around Knock depends on the weather, as sealant needs a dry surface, so an outdoor job can move if the forecast changes. Indoor work goes ahead whatever the weather.
- First, we go round the frames with you and agree the list.
- We remove the old mastic and clean the frame edge and wall.
- Where the gap is deep, backing rod goes in first.
- A flexible exterior sealant is applied in a colour to suit the frame.
- We tool each bead neatly and check every joint is closed.
How to prepare
- Where the joints are inside, avoid wetting them before we arrive
- For business premises, tell us about site rules or sign-in
- Let us know about earlier repairs to the joints
Getting a quote
Quotes start with a quick conversation. Describe the problem, the location and the size of the job, and we will explain how we’d tackle it. Whenever you’re ready, send an email to info@mrmastic.co.uk.
Related advice
Surface by surface
Composite doors
Composite doors are normally hung in an uPVC-type frame, and the joint around it is sealed like a window. We match the colour to the frame.
Window sills
Stone and concrete sills have their own joints, and the joint under the frame can let rain run behind. We seal those with a sealant suited to masonry.
What affects the quote in Knock
There’s no set price list, because no two jobs are the same. The quote depends on:
- The number of rooms or windows
- Access and height
- When we can work, for business premises
- Whether old sealant or filler has to be cut out
We don’t show prices on the website, because the cost depends so much on the job itself. For a quick quote, please email us at info@mrmastic.co.uk.
What we need to know
You don’t need to know the technical terms. Just tell us:
- The rough size of the job
- Whether it’s a home or a business
- Any access issues, like height or stairs
- A few pictures by email, if you can
Asking for a quote is easy: let us know the job and the location. A few photos by email make the job easier to understand, and we will take it from there.
Window mastic in Knock: local notes
Knock 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. That’s hard on the mastic around window and door frames, especially on the side facing the sea. Work on the islands has to be planned around ferry crossings and the weather, so the more notice, the better.
In and around Knock, as anywhere, good window mastic starts with a clean, dry, properly prepared joint. For jobs in and around Knock, choosing the right material for each joint is as important as a tidy finish.
Knock (Gaelic: An Cnoc) is in Na h-Eileanan Siar. Jobs in Knock get the same care as everywhere else we work: the old material taken out, joints prepared properly and a 12-month guarantee. Our Na h-Eileanan Siar coverage runs to 87 places, Knock among them.
All of HS2 is covered for window mastic, from the main roads to the quietest streets. Local streets include Seaview and A' Chnuic. Knock is on the A866, which makes it straightforward to reach with everything needed for window mastic. We also cover the places around Knock: Na h-Eileanan an Iar (1 mile west), Aiginis (1 mile west), Lower Bayble (1 mile east), Garrabost (2 miles north-east) and Pabail Uarach (2 miles east). For island and remote addresses, a little more planning is needed, so let us know when you get in touch.
Local landmarks in Knock
A little further out are Western Isles Hospital (4.5 miles west).