West Sussex · England
Duncton Window Mastic
We cover Duncton for mastic around window and door frames, sills and patio doors. Old sealant removed completely, joints prepared properly.
- Gaps where the sill meets the wall
- Mastic that’s falling out in pieces
- Draughty joints inside around the window
Window mastic in Duncton
Behind a thin line of old mastic there’s sometimes a deep void. Filling it with sealant alone leaves a joint that can’t move properly, so deep gaps get backing rod first. That way the new bead bonds to the frame and the wall only. We work on window sills, composite doors and aluminium frames, and people most often call us about old mastic that has gone black or come away and a bead that doesn’t match the frame.
Homes in small places like Duncton often stand in the open, with little to shelter their windows from wind and rain. That exposure dries out and cracks the mastic around frames and sills faster.
Big or small, it’s backed by our one-year guarantee.
- Location
- Duncton (GU28)
- Wider area
- West Sussex
- Guarantee
- 12 months on all our work
- Price
- A clear quote up front
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
Duncton questions
Do you cover Duncton for window mastic?
Yes. We work across London and the South East, and Duncton is part of that. You can phone 0345 464 0079 or drop us an email and let us know what needs doing.
Is Duncton within the area you cover?
Yes, smaller places are covered as well as towns. We work across London and the South East. Let us know about access, parking and anything unusual about getting there when you book.
What do you put in the joint?
Products from Arbo and Everbuild, among others, picked for each joint. We’ll tell you what we’re using and why.
Are you fully insured?
Yes. Full insurance covers our work.
Is the work guaranteed?
Yes, with our one-year guarantee. Keeping drainage clear and checking the joints yearly helps them last.
Can new window sealant be painted?
Most silicone cannot be painted. If you plan to paint, tell us first and we can use a paintable sealant where it suits the joint.
Can you quote for more than one area?
Yes. Just list everything you need and you will get one quote.
I rent my home. Can I book you?
Of course. Ask your landlord first, and we can send them the quote if that helps.
Landlords, agents and businesses in Duncton
Housing providers, facilities teams and property managers book us too in Duncton and across West Sussex. Several sites can be quoted together, and we are fully insured for the work.
Water getting past a failed joint can damage the building, which is a bigger problem in a rented property. Resealing at the right time is simple maintenance.
What affects the cost of window mastic
We don’t publish a price list, because no two jobs are the same. What we look at:
- The size of the job
- Any working-time requirements on site
- Any mould that needs treating
- The type of sealant required
Instead of a standard rate, we look at what your job involves: the amount of work, the old material and the access. The price is agreed before we begin.
What we need to know
The more you tell us, the more accurate the quote. When you ask for a quote, tell us:
- What’s wrong with the joints now
- Any access issues, like height or stairs
- A few pictures by email, if you can
- Whether it’s a home or a business
Getting a quote is simple: let us know what needs doing and where. Photos by email help us understand the job.
How it works
There is not much for you to do on the day. Point us to the joints and we will get on with it. The job generally takes a morning for a couple of windows and a door. For a village or hamlet like Duncton, the journey is planned in advance: let us know about lanes, gates and parking. We bring what the job needs, so it can be finished in one trip where possible.
- First we look at every frame and agree the list.
- We remove the old mastic and clean the frame and the wall.
- Where gaps are deep, backing rod goes in first.
- We apply a weatherproof sealant to match the frame and tool it neatly.
- Every joint is checked before we leave.
Getting ready for the visit
- Move anything stored near the joints
- On commercial sites, let us know about site rules
- Mention any parking rules near the property
Getting a quote
For a quick quote, get us on the phone, or email us if that’s easier. Describe what needs sealing and we will talk you through the work.
Related advice
When it is not the sealant
Before you book, it’s worth knowing the limits:
- Penetrating damp from a failed cavity tray or render
- Rotten timber, which needs a joiner first
- Misting between the panes of a double-glazed unit (that needs a new unit)
If in doubt, call 0345 464 0079 or email us and we will say what we think before you book.
What we seal
- uPVC windows
- Window sills
- Timber windows & doors
- Patio & French doors
- Aluminium frames
- Composite doors
Do you need window mastic in Duncton?
Joint shape matters as much as the product. A skim of sealant over a wide gap soon tears, while a joint packed solid can’t stretch. That’s what backing rod is for.
People normally contact us after spotting something like this:
- White mastic on grey or black frames
- Cold air getting in at the frame edge
- Gaps left after new windows were fitted
- Cracked internal joints between frame and plaster
For site and facilities teams at buildings such as Duncton CofE Junior School, its window and door frames need their mastic kept sound, just like a home’s.
What your quote should include
- What preparation is included
- Who turns up on the day
- Whether VAT is included
- Which colour the sealant will be
Other services in Duncton
What the job involves on each surface
Timber windows & doors
Where timber has rotted at the joint, it needs repairing first. If we find rot, we will tell you before going ahead, as a joiner will need to deal with it.
Composite doors
If the door itself is draughty, the issue may be the door seals or hinges rather than the frame mastic. We will tell you if that is what we find.
What window mastic looks like in Duncton
Compared with the north and west, the South East gets less rain, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind. Historic houses like Bignor Roman Villa (about 2.4 miles south-east) are a reminder that the area around Duncton has older buildings as well as new. In older buildings, older timber frames in brick or stone need a different approach from a modern uPVC window.
In the older streets around Church of Holy Trinity, frames set in older brick or stone need a sealant that suits the wall as well as the frame.
Duncton is about 10 miles north-east of Chichester, in West Sussex. From the centre of Duncton to the outskirts, we cover window mastic for every kind of property, from flats and houses to offices and hotels. Duncton is one of 371 towns and villages in West Sussex where we work for window mastic. You can also see our page for Crawley, roughly 22 miles from Duncton.
We cover every part of the GU28 postcode area for window mastic and the streets around it. That includes homes and businesses on Duncton High Street and Willett Close and the roads around them. Neighbouring places we cover for window mastic include East Lavington (1 mile south-west), Sutton (2 miles south-east), Rotherbridge (2 miles north), Graffham (2 miles west) and Haslingbourne (2 miles north-east). Within a short drive, we also cover Worthing (13 miles south-east), Bognor Regis (11 miles south), Chichester (10 miles south-west), Littlehampton (10 miles south-east), Emsworth (15 miles south-west) and Rustington (11 miles south-east).
Local landmarks in Duncton
Typical jobs here are in homes near The Parish Church of St Peter. Well-known places in the area include Midhurst Community Hospital (5.4 miles north-west) and Coultershaw Heritage Site (1.6 miles north-east). Green spaces nearby include Bignor Hill and Graffham Common.
Why act early in Duncton
Draughts and leaks don’t always mean new windows. Where the frames are sound, new mastic usually deals with draughts and leaks at the edges. If we find failed glass units or worn seals, we’ll tell you. Older cottages and farmhouses around Duncton can have timber floors and frames, where water from a failed joint can cause rot if it’s left.
What it costs depends on the amount of work, how hard the old material is to remove and how easy the joints are to reach. You will have a clear quote before any work starts.
Why Duncton clients choose us
- Full insurance on every job
- Tidy, careful work
- Approved under the ARBOMaster scheme
- You choose the colour before work begins
See our cost guide and our reviews.