Buckinghamshire · England
Window Mastic in High Wycombe
Problem with your window and door frames in High Wycombe? We cut out the old, prepare the joints and apply the right sealant, with a 12-month guarantee.
- Gaps between the frame and the inside reveal
- Draughts coming in around windows and doors
- Sealant in the wrong colour for the frame
How the job changes by surface
Aluminium frames
Coated aluminium needs a compatible sealant and we avoid acetoxy silicones, which can react with some metals. We use a neutral-cure product.
Patio & French doors
The joints around patio doors run a long way, top, sides and threshold. Most leaks start at the bottom corners, so they get particular care.
How we handle window mastic in High Wycombe
Mr Mastic’s applicators have more than 20 years’ experience with window and door sealants. We’re fully insured ARBOMaster approved applicators, and we give a one-year guarantee on the work. Common call-outs are for gaps left after new windows were fitted and black, perished sealant on frames, across patio & French doors, aluminium frames and uPVC windows.
Around High Wycombe, many houses have gained conservatories, French doors or replacement windows over time. Each one adds more joints to look after, and those joints age at different rates. Leaks usually start at a sill, a frame head or a glazing joint.
Our work is backed for twelve months, and the guarantee is the same wherever you are.
- Location
- High Wycombe (HP13, HP11, HP12, HP10)
- Region
- Buckinghamshire
- Guarantee
- 12 months on all our work
- Quote
- A clear price before work begins
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
High Wycombe homes and the weather
Historic houses like Hughenden Manor (about 1.5 miles north) are a reminder that the area around High Wycombe 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. The South East is one of the drier parts of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
If you look after a building such as Hamilton Academy, larger buildings have plenty of frames, and the mastic around each one ages. Rented homes near High Wycombe station change hands often, and renewing tired window mastic between tenants heads off draught and damp complaints. If you live in an older home near Church of All Saints, the windows may be timber, sash or later replacements, and each needs the right sealant against the wall.
High Wycombe is about 28 miles south of Milton Keynes, in Buckinghamshire. We carry out window mastic for homeowners, landlords and businesses in High Wycombe and nearby. Our Buckinghamshire coverage runs to 263 places, High Wycombe among them. Our Reading page covers work nearby, about 16 miles away.
All of HP13, HP11, HP12 and HP10 is within our area for window mastic, from the main roads to the quietest streets. Streets in the area include High Street, Church Square and Queens Square, all of which we cover. You’ll find High Wycombe on the A40 and A404, which makes it straightforward to reach. We also cover the places around High Wycombe: Totteridge (1 mile east), Terriers (1 mile north-east), Wycombe Marsh (1 mile south-east), Micklefield (1 mile east) and Downley (2 miles north-west). Within a short drive, we also cover Aylesbury (13 miles north), Chesham (8 miles north-east), Marlow (4 miles south), Amersham (7 miles north-east), Beaconsfield (5 miles east) and Chalfont St Peter (8 miles east). High Wycombe is one of the larger places we cover in Buckinghamshire.
What’s near High Wycombe
Around High Wycombe, our work takes us to homes and buildings near London Central Elementary High School, Three Tuns Public House and The Tower. High Wycombe has its own railway station: High Wycombe station. Well-known places in the area include Eden (under half a mile west) and High Wycombe Castle (within half a mile north). For a walk, there’s Gomm's Wood.
Looking after it afterwards
How long the joints last depends on use and care. We suggest:
- Look round the frames every year or so
- Repaint timber before it’s bare
- Make sure the drainage slots are not blocked
- Paint up to the joint, not over it
Most silicone sealants won’t take paint, so mention any painting plans before work begins. We can use a paintable sealant where that matters.
A small gap around a frame only grows. As the old mastic shrinks further, more air gets through, and a cold room gets colder. Resealing closes it.
Also near High Wycombe
Other services in High Wycombe
Quotes for window mastic in High Wycombe
Your quote is based on your job. We take into account:
- Mould in or behind the old joints
- How many rooms, windows or areas are involved
- The old material and how stubborn it is
- The size of the job
Rather than a set price list, we price the job in front of us: the amount of work, the old material and the access. The price is agreed before we begin.
What to tell us for a quote
Photos help, but a description is a good start. Try to tell us:
- Where the property is
- Any access issues, like height or stairs
- What the problem is, such as mould, gaps, leaks or cracking
- If it’s domestic, commercial or a hotel
For a quote, phone 0345 464 0079 or email us and tell us where the job is and what the problem looks like. We will give you a clear quote before any work starts.
What happens if it’s left?
A quick bead over the top of old mastic looks like an easy fix, but new sealant can’t bond to old, crumbling mastic. It peels before long, and water still gets in behind. The old mastic has to come out. Around High Wycombe, failed sealant lets water into hidden places, such as under the floor, behind a panel or into a wall. Whatever the joint, failed sealant only gets worse.
We do not show prices on the website, because each job is priced on what it involves. Call for a quick quote and we’ll talk you through it.
Why book with us
- 20+ years of sealant experience
- We never seal over old sealant
- White, clear, grey or coloured to suit, where the product allows
- A sealant colour to suit the surroundings
See what affects the cost and our reviews.
Work for landlords, hotels and businesses
For anyone letting property in or around High Wycombe, jobs at different addresses can go on one quote. Send us the addresses and the work at each.
In hotels, rooms out of use cost money, so the work can be planned room by room around your bookings where we can. Hotel work is part of what we do, alongside homes and businesses.
Common questions in High Wycombe
Is there a guarantee on window mastic in High Wycombe?
Every job comes with our one-year guarantee, wherever it is. We’re also fully insured and ARBOMaster approved.
Do you cover High Wycombe for window mastic?
Yes, High Wycombe is within the area we cover. Our work covers London and the South East. Just phone 0345 464 0079 or email us with a few details of the job, and we will give you a clear quote.
Can you seal over the old sealant?
No, and we never do. It can look neat for a few weeks, but the new bead soon lifts. Removing the old sealant completely is the only lasting way.
How long will my window job take?
That depends on the number of frames, how they’re reached and the state of the old mastic. You will know the timing when we quote.
Do you work on first-floor windows?
Yes, where they can be reached safely. Tell us about access when you get in touch so we can plan the job.
Can I do it myself?
Sometimes. The key is preparation: remove all the old material and work on a clean, dry joint. If it does not work out, we can redo it.
Do I have to be there?
For indoor joints, yes, someone needs to let us in. After that, you can carry on with your day.
Can you do the inside joint as well?
Yes. The outside joint keeps the weather out, and the inside joint stops draughts and finishes the reveal. We do one or both.
How it works
You do not need to clear the whole room or building before we come, only the area right around the joints. We protect the rest, and the work takes a few hours for a few frames, or a day or more for a whole house for a typical job. A visit in High Wycombe needs access to the work and a place to park close by. If the job is outside, mention gates, side access and anything above ground floor.
- We check how each frame can be reached safely.
- All the failed sealant is cut away, along with any loose debris.
- The surfaces are cleaned and left dry.
- Deep voids are backed, then the sealant is gunned in.
- We tool the joint so water runs off, then clear up.
How to prepare
- On commercial sites, let us know about site rules
- Clear items away from the joints we’re working on
- Mention any leaks or damp you’ve noticed
Ask for a quote
Quotes start with a quick conversation. Describe the problem, the location and the size of the job. Whenever you’re ready, phone 0345 464 0079 or send us an email.
Advice
Should I try it myself first?
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.
The biggest DIY mistake is sealing over old sealant. New silicone will not bond to old, so it peels away and traps moisture behind it. Everything old must be removed first.