West Sussex · England
Window Mastic in Washington
Problem with your window and door frames in Washington? We remove the old material, prepare the joints and seal them properly, and the work is guaranteed for a year.
- Old mastic that has gone black or come away
- Draughts coming in around windows and doors
- Cracked or shrunken mastic around the frame
Frames and glazing around Washington
With historic houses such as Parham House (about 3.9 miles west) nearby, there’s older building stock in the area around Washington as well as newer homes. In older buildings, older frames set in brick or stone need a sealant that suits them, and sometimes that is traditional sand mastic. Rainfall in the South East is lower than in much of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
For an older house near a landmark such as The Parish Church of St Mary, frames set in older brick or stone need a sealant that suits the wall as well as the frame.
Washington is about 6 miles north of Worthing, in West Sussex. We carry out window mastic for homeowners, landlords and businesses in Washington. Our West Sussex coverage runs to 371 places, Washington among them. We also work in Brighton, around 13 miles away.
All of RH20 is covered for window mastic. Streets in the area include London Road, The Street and Chanctonbury Close. Other places close to Washington include Rock (1 mile north), Sullington (1 mile west), Heath Common (2 miles north-west), Storrington (2 miles north-west) and Warminghurst (2 miles north). Within a short drive, we also cover Horsham (12 miles north), Worthing (6 miles south), Bognor Regis (15 miles south-west), Haywards Heath (15 miles north-east), Burgess Hill (13 miles east) and Littlehampton (8 miles south-west).
What’s near Washington
We work in homes and buildings around Rydon Community College, Windlesham House School and The Frankland Arms Public House. Nearby you will also find The Storrington And District Museum (2 miles north-west). For a walk, there’s Chanctonbury Hill.
Window mastic for homes and businesses in Washington
The new joint doesn’t have to be white. We can seal in white, brown, anthracite grey, black or clear, so the line suits the frame instead of standing out. We are often asked to deal with whistling draughts around closed windows and cracked or shrunken mastic around the frame, across patio & French doors, uPVC windows and aluminium frames.
In a village or hamlet like Washington, older cottages and farmhouses often have timber windows set in stone or brick. Not every older frame suits a modern silicone bead, so the sealant has to be chosen to suit the building.
The work is guaranteed for twelve months. If there’s a problem with our work within the year, let us know and we will sort it.
- Place
- Washington (RH20)
- Wider area
- West Sussex
- Guarantee
- 12 months on all our work
- Quote
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
Places near Washington
Also in Washington
Common problems we fix in Washington
Mastic ages in the weather. UV light hardens the outside of the bead, until it loses its stretch and starts to crack.
Most people get in touch when they notice something like this:
- Draughts coming in around windows and doors
- Cracked internal joints between frame and plaster
- Mastic that is falling out in pieces
- Gaps where the sill meets the wall
Schools such as St Mary's CofE Primary School are buildings too, and its window and door frames need their mastic kept sound, just like a home’s.
Before you book anyone
- Whether they seal over old material or remove it
- How long to leave it before use
- Is VAT in the price?
- Who turns up on the day
Landlords, agents and businesses in Washington
Landlords and letting agents in Washington can book us as well as householders. Resealing between tenancies keeps a property looking cared for.
Businesses can book us for washrooms, kitchens, offices and more. For commercial premises, we can talk through working times when we quote.
Your questions about window mastic in Washington
Is window mastic in Washington guaranteed?
Every job comes with our 12-month guarantee, wherever it is. We are also fully insured and ARBOMaster approved.
Is Washington in your area for window mastic?
Yes, Washington is within the area we cover. We work across London and the South East. Just call 0345 464 0079 or drop us an email with a few details of the job.
Can you seal the gap between the frame and the plaster indoors?
Yes. Outside is the weather seal; inside closes the gap to the plaster. We can do either or both.
Will the old sealant be removed?
Always. Sealing over the old bead is the commonest cause of early failure, so we never do it.
What should I tell you?
Let us know what needs doing and where, plus photos if you have them. We will ask anything else we need to know.
Where are you based?
Mr Mastic is based in Crawley. We cover Washington and the rest of West Sussex, along with the rest of our area.
How much does window mastic cost in Washington?
The cost depends on the size of the job, access and how much old sealant has to come out. Ask us for a quote and we will talk you through it.
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.
What happens on the day
We work through the job in order: protection first, then preparation, sealing and a tidy-up. For most jobs that takes anything from an hour or two to a full day, depending on how many frames there are. Somewhere as small as Washington, access is often the only tricky part. If the job is outside, mention outbuildings, exposed walls and how to reach them.
- First, we confirm safe access to each frame.
- All the failed sealant is cut away.
- The surfaces are cleaned and left dry.
- Backing rod fills deep voids and the sealant goes in on top.
- We tool the joint so water runs off, then clear up.
Preparing for the visit
- Keep children and pets away from the work area
- Mention any sign-in or site rules at work premises
- Tell us about any previous sealing or DIY attempts
Getting a quote
Every job is quoted individually, so start by telling us what you need. Just ring 0345 464 0079 or email us with the details, and pictures are welcome.
Read more
DIY sealant or a professional job?
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.
Too much sealant is as bad as too little. A thick, smeared bead looks untidy and does not move well, and getting the depth right matters as much as the look.
Why it’s worth doing now in Washington
Working on frames from a ladder with a sealant gun isn’t easy, especially on upper floors. We cut out properly, back deep gaps and tool every joint neatly, in a sealant suited to the wall. Where a wall is exposed, as many are in small places like Washington, wind-driven rain gets into any failed joint, and older walls, once damp, take a long time to dry.
Every job is a little different, so we quote each one individually. Size, access and the product the joint needs all play a part, and we will explain the quote if you ask.
Why choose Mr Mastic in Washington
- Anti-fungal sanitary silicone in wet areas
- We agree the colour with you first
- One-year guarantee on every job
- White, clear, grey or coloured to suit, where the product allows
Take a look at what affects the cost and our reviews.
How to look after the new joints
How long the joints last depends on use and care. Here’s what we suggest:
- Keep drainage slots and sill grooves clear
- Paint up to the joint, not over it
- Avoid harsh chemicals near the mastic
- Keep paint and stain on wooden frames in good order
Keep sill grooves and drainage slots clear, so water can run away instead of sitting against the joint.
Water gets in quietly when mastic fails. Often the first sign is a damp patch inside or flaking paint on the reveal. Early resealing stops it reaching that point.
Different surfaces, different methods
Composite doors
If the door itself is draughty, the issue may be the door seals or hinges rather than the frame mastic. We seal the frame and let you know about anything else.
Aluminium frames
Large aluminium doors have long joints down each side and across the head, and the threshold joint takes a lot of water. Each is cleaned, backed where deep and resealed.