Buckinghamshire · England
Finmere Window Mastic
Mastic around window and door frames, sills and patio doors in Finmere, with a 12-month guarantee on every job. Ask us for a quote.
- Rain getting in at the frame or under the sill
- Old mastic that has gone black or come away
- Cracked or shrunken mastic around the frame
Window mastic for homes and businesses in Finmere
A cold draught around a closed window often comes from the frame edge. A new joint stops the air getting through and quietens the whistle on windy days. If the draught is through the window seals instead, we’ll tell you. If you are dealing with mastic that has split away from the wall and gaps between the frame and the inside reveal, we can put it right.
Homes in small places like Finmere often stand in the open, with little to shelter their windows from wind and rain. Exposed frames and sills lose their mastic sooner than sheltered ones.
We guarantee the work for a year. If there’s a problem with our work within the year, let us know and we will sort it.
- Place
- Finmere (MK18)
- Region
- Buckinghamshire
- Guarantee
- A year, on every job
- Quote
- A clear quote up front
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
FAQs for Finmere
Is there a guarantee on window mastic in Finmere?
Every job comes with our 12-month guarantee, wherever it is. We are also fully insured and ARBOMaster approved.
Do you cover Finmere for window mastic?
Yes. Our work covers London and the South East, and Finmere is part of that. You can phone 0345 464 0079 or email us and let us know what needs doing.
Can you do upstairs windows?
Yes, where it’s safe. Higher or awkward frames may need extra access, and we’ll confirm what’s needed.
Is it OK to seal over old sealant?
No. The old sealant always comes out first, so the new sealant bonds properly.
Can you match the sealant to my frames?
Yes, we choose a colour to suit the frame. Anthracite grey, black, brown and white cover most frames, with clear as an option.
Do the sealants smell?
Some sealants have a smell while they cure. Opening a window helps.
Where is Mr Mastic based?
We’re based in Crawley, West Sussex, and we cover South East England, London and all of Scotland.
How many windows can you do in a day?
A handful of frames is a short visit. You will get a timescale with the quote.
How to look after the new joints
After the cure time, these simple habits help:
- Air rooms to keep condensation down around windows
- Do not aim a pressure washer at the joints
- Clear any debris from frame drain holes
- Wash the frames with mild soapy water
Timber frames need their paint kept up, because bare, wet timber moves more and pulls at the joint. Paint up to the joint, not over the silicone.
Draughts get worse, not better. As old mastic keeps shrinking, the gap widens, and heat escapes around the frame. Resealing closes it.
Window mastic in Finmere: local notes
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. Historic houses like Stowe House (about 3.7 miles north-east) are a reminder that the area around Finmere has older buildings as well as new. Where a home is older, older frames set in brick or stone need a sealant that suits them, and sometimes that’s traditional sand mastic.
In the older streets around Church of St Michael, the joint between an old wall and a newer frame is normally the first place rain gets in.
Finmere is about 4 miles west of Buckingham, in Buckinghamshire. If you need window mastic in Finmere, please ring 0345 464 0079 or drop us an email for a quick quote. We cover Buckinghamshire from our Crawley base. Our area takes in 263 places across Buckinghamshire, large and small. There’s also a page for Oxford, roughly 18 miles from Finmere.
Here we cover the MK18 postcode area for window mastic. Local streets include Chinalls Close, Stable Close and Fulwell Road. If you’re just outside Finmere, we cover Tingewick (1 mile east), Preston Bissett (2 miles south-east), Gawcott (3 miles east), Hillesden (4 miles south-east) and Twyford (4 miles south-east). Larger places within reach include Buckingham (4 miles east), Haydon Hill (15 miles south-east), Winslow (9 miles east), Steeple Claydon (5 miles south-east), Long Crendon (15 miles south) and Whitchurch (13 miles south-east).
Near you in Finmere
Other landmarks nearby include The Menagerie (3.6 miles north-east) and Buckingham Community Hospital (3.9 miles east). Not far away are Buckingham Sand Pit.
What we can’t put right
We will not take on work that will not last, so these are the limits:
- Damp coming through the wall itself rather than the frame joint
- Faulty window hardware
- Misting between the panes of a double-glazed unit (that needs a new unit)
Not sure which it is? You can call 0345 464 0079 or drop us an email and we will tell you honestly.
What we seal
- Timber windows & doors
- Aluminium frames
- Composite doors
- Patio & French doors
- uPVC windows
- Window sills
Should I try it myself first?
A careful DIYer can reseal a simple joint, such as a straightforward joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
If you’ve already had a go yourself, that is fine. We cut it out and start again.
How we quote for window mastic
You’ll get a clear quote before work begins. It’s based on:
- How many areas need sealing
- Whether the work is at height
- Whether old sealant or filler has to be cut out
- When we can work, for business premises
The cost reflects the work involved, not guesswork. That’s why we ask a few questions first.
Helping us quote
You don’t need to know the technical terms. It helps if you can tell us:
- If it’s domestic, commercial or a hotel
- Any previous sealing or DIY work
- The address or postcode of the job
- Roughly how big the job is
A good description makes for an accurate quote. Let us know the location, the problem and roughly how many joints, and email pictures if that is easy.
Also near Finmere
Other services in Finmere
Why deal with it now?
Not every sealant suits a window. Interior caulk and bathroom silicone are not made for exterior frame joints. An exterior, low-modulus sealant stays flexible in sun and frost. Around Finmere, older homes often have timber in their floors and frames, where water from a failed joint can cause rot if it’s left.
A few things move the cost up or down: how much old sealant there is and how stubborn it is, whether mould needs treating, and whether the work is at height. Your quote takes all of that into account.
Why book with us
- Over 20 years’ experience
- Colour agreed with you before we start
- Domestic, commercial and hotel work
- An ARBOMaster approved applicator
See what affects the cost and our reviews.
What happens on the day
At the end, we look at the finished work together. The work normally takes a morning for a couple of windows and a door, depending on the size of the job. Somewhere like Finmere needs a little journey planning: tell us about narrow lanes, gates, long drives and where we can park. We bring what the job needs, so it can be finished in one trip where possible.
- First, we confirm safe access to each frame.
- 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.
- The joint is shaped to shed water and the area tidied.
Getting ready for the visit
- Keep pets and children clear of the area while we work
- Let us know about stairs, lifts or work at height
- Mention any sign-in or site rules at work premises
How to get a quote
For a quote, ring 0345 464 0079 or drop us an email and tell us where the job is and what the problem looks like. We will give you a clear quote before any work starts.
Advice
Common problems we fix in Finmere
Plenty of failed mastic was poorly applied in the first place. Mastic laid onto dusty, damp or crumbling surfaces didn’t grip properly, and it lets go sooner than it should.
The problems people generally mention when they call include:
- Sealant in the wrong colour for the frame
- Hard, cracked sealant around windows
- Black, perished sealant on frames
- Gaps between the frame and the inside reveal
If you look after a building such as Finmere Church of England Primary School, larger buildings have plenty of frames, and the mastic around each one ages.
Comparing quotes
- How long to leave it before use
- What insurance they hold
- Whether they seal over old material or remove it
- Who turns up on the day