Slough · England
Window & door mastic in Upton, Slough
Mastic around window and door frames, sills and patio doors in Upton, with a 12-month guarantee on every job. Ask us for a quote.
- Black, perished sealant on frames
- White mastic on grey or black frames
- Rain getting in at the frame or under the sill
Window mastic in Upton
Some gaps around frames are far deeper than they look. Filling it with sealant alone leaves a joint that cannot move properly, so we fit backing rod to set the right depth. The sealant then grips the two sides it should. We work on composite doors, aluminium frames and timber windows & doors, and people most often call us about a bead that doesn’t match the frame and mastic that has split away from the wall.
In smaller places like Upton, homes range from older cottages to newer houses, with windows to match: timber, uPVC and aluminium. Each frame material needs the right sealant against the right wall.
Whatever the size of the job, you get the same one-year guarantee in Upton and across Slough.
- Place
- Upton (SL1, SL3, SL2)
- Region
- Slough
- Cover
- 12 months on all our work
- Quotes
- A clear price before any work starts
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
When it isn’t the sealant
It helps to know what we cannot do too:
- Broken hinges, locks or handles
- A failed sealed unit that has misted up
- A door that needs adjusting, rehanging or new seals
If in doubt, phone 0345 464 0079 or drop us an email and we’ll say what we think before booking.
Surfaces we seal
- Aluminium frames
- Timber windows & doors
- Composite doors
- Window sills
- Patio & French doors
- uPVC windows
The process
Most of a good job is in the preparation, and we do not rush it. Every joint is cleaned and dried before new material goes in. In total, it generally takes most of a day for a typical house, less for a few frames. For a job in Upton, we agree the time, the access and parking before the day. If the work is outside, the weather plays a part, as sealant needs a dry surface.
- We start by checking each window and door with you.
- Next the failed sealant is cut away and the joint cleaned.
- Where gaps are deep, backing rod goes in first.
- A flexible, weatherproof sealant is applied in a colour to suit the frame.
- Every joint is checked before we leave.
How to prepare
- For business premises, tell us about site rules or sign-in
- Tell us if parking is tricky
- Tell us about any previous sealing or DIY attempts
Getting a quote
Want a quote for window mastic? Please phone 0345 464 0079 or drop us an email with a few details. We’ll explain what we’d do and give you a clear quote before work begins.
Related advice
Why it’s worth doing now in Upton
If you are painting or rendering, reseal at the same time. A clean new bead makes new paint or render look finished, and it’s easier while the walls are being worked on anyway. In a smaller place like Upton, wherever a wall is exposed, a failed outside joint is a real source of damp. Inside, a split seal lets water into floors and panels just as it would anywhere.
Leaving a failed joint usually makes the job bigger, not smaller, as water and mould keep getting in. If you are not sure whether it needs doing, phone 0345 464 0079 or email us for an honest opinion and a quote.
Why choose Mr Mastic in Upton
- Sealant colour chosen to suit
- 20+ years of sealant experience
- Any old sealant cut out fully, not covered over
- Rated 4.9 stars on Google
Take a look at how sealant jobs are priced and customer reviews.
What the job involves on each surface
Patio & French doors
Not every patio door leak is a mastic problem: worn seals, blocked drainage slots or a poor threshold detail can be the cause. We look for the cause first.
Composite doors
A composite door generally sits in a plastic outer frame, so its perimeter joint is sealed much like a window. We match the colour to the frame.
Looking after it afterwards
Good habits help new joints last longer. Our tips:
- Keep drainage slots and sill grooves clear
- Air rooms to keep condensation down around windows
- Keep paint off silicone joints
- Clean frames with a soft cloth and soapy water
Wipe the frames with soapy water when you clean the windows, and keep solvents and harsh chemicals off the joint.
Wet, windy weather is when failed mastic shows itself, but sealant goes on best when frames and walls are dry. Sorting cracked mastic early means the joint is sound before the bad weather.
Upton: your questions answered
Is Upton in your area for window mastic?
Yes, Upton is within the area we cover. We work across London and the South East. Just call 0345 464 0079 or email us with a few details of the job, and we will give you a clear quote.
I let a flat near Slough station. Can you help?
Yes. We work for landlords and agents as well as householders. You can call 0345 464 0079 or send us an email with the details for a clear quote.
Is the work guaranteed?
Yes. Our one-year guarantee covers every job, inside or out.
Do you take out the old sealant first?
Yes. We cut out all the old sealant and clean the joint before applying anything new.
Can you do the inside joint as well?
Yes. Indoors, we seal between the frame and the plaster or reveal, using a paintable sealant if you want to decorate.
Will new mastic stop draughts?
It will if the frame joint is the problem. We check where the draught is before work begins.
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.
Are you insured?
Yes. We’re fully insured, and we’ve been doing sealant work for more than 20 years.
Landlords, agents and businesses in Upton
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.
Businesses can book us for washrooms, kitchens, offices and more. For commercial premises, we can talk through working times when we quote.
Frames and glazing around Upton
Compared with the north and west, the South East gets less rain, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day. Historic houses like Windsor Castle (about 1.5 miles south-west) are a reminder that the area around Upton has older buildings as well as new. In older buildings, older frames set in brick or stone need a sealant that suits them, and sometimes that is traditional sand mastic.
If you let a flat or house near Slough station, sound mastic around windows and doors keeps out the draughts and damp that tenants notice first. If you live in an older home near Church of St Laurence, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint. If you look after a building such as St Mary's Church of England Primary School, its window and door frames need their mastic kept sound, just like a home’s.
Upton is about 1 mile south-east of Slough, in Slough. We provide window mastic to homes and businesses in Upton and the surrounding area. Across Slough, we cover 31 places, and Upton is one of them. You can also see our page for Reading, roughly 17 miles from Upton.
Our applicators cover all of the SL1, SL3 and SL2 postcode area for window mastic. Whether your property is on Mere Road, Upton Road and High Street or anywhere close by, we can help. You will find Upton on the M4 and A332, which makes it straightforward to reach with everything needed for window mastic. We also cover the places around Upton: Middlegreen (2 miles east), Langley (2 miles east), George Green (2 miles north-east), Wexham Court (2 miles north) and Wexham Street (3 miles north). Larger places within reach include Britwell (3 miles north-west), Burnham (3 miles north-west), Stoke Poges (3 miles north), Huntercombe (3 miles north-west), Farnham Common (4 miles north) and Farnham Royal (3 miles north-west). Being one of Slough’s larger places, Upton has homes, rented property and businesses of every kind.
What’s near Upton
Locally, jobs take us to homes and businesses close to The Red Cow Public House, Upton Court Grammar School and Long Close School and the streets around them. Upton’s nearest station is Slough station, roughly 0.6 miles north. Other landmarks nearby include Windsor Castle (1.5 miles south-west) and Museum of Eton Life (1.2 miles south-west). For a walk, there’s Stoke Common and Taplow Lake.
Towns and villages near Upton
Also in Upton
DIY sealant or a professional job?
Some jobs are best left to a professional: high-level joints, fire-rated gaps, external movement joints and big jobs call for the right materials, safe access and experience.
A careful DIYer can reseal a simple joint, 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.