Buckinghamshire · England
Finmere External Mastic
External mastic across Finmere and nearby, with old sealant always removed completely and a 12-month guarantee.
- Brick movement joints where the sealant has split
- Weeds or debris growing in open joints
- Leaking joints around cladding and façade panels
External mastic for homes and businesses in Finmere
Many failed façade joints only get noticed once there’s a stain or a damp patch inside. We inspect them, agree which need doing and reseal with a weatherproof, flexible sealant in a colour to suit. We’re often asked to deal with rigid filler in a joint that should flex and water getting into walls through failed joints, across copings & trims, render & cladding joints and façade panels.
In a village or hamlet like Finmere, older cottages and farm buildings often stand in the open, where walls and rooflines take the weather head on. Joints on those walls need a sealant that moves with the building and stays in place.
Big or small, it’s backed by our one-year guarantee in Finmere and across Buckinghamshire.
- Place
- Finmere (MK18)
- Wider area
- Buckinghamshire
- Guarantee
- One year on every job
- Quotes
- A clear price before we start
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
When it isn’t the sealant
New sealant can’t fix everything, and we’ll tell you before work begins. It will not solve:
- Cracking across the wall rather than at a joint
- Loose or hollow render, which needs re-rendering
- Rising or penetrating damp from elsewhere in the wall
If you’re not sure, just ring 0345 464 0079 or email us and we’ll give you a straight answer before you book.
Where we work in Finmere
- Concrete & block
- Copings & trims
- Joints between brick and frames
- Render & cladding joints
- Brickwork movement joints
- Façade panels
Looking after it afterwards
Simple care keeps the joints in good condition. Our advice:
- Leave the joints unpainted unless we have said otherwise
- Wash walls gently around the sealant
- Point out the joints to other trades
- Never let anyone fill a movement joint with mortar
Do not paint over the new sealant unless we have said the product is paintable. Paint can crack on a flexible joint.
Act while the splits are small. At that stage it’s a simple cut out and reseal.
Places near Finmere
Other services in Finmere
What external mastic looks like in Finmere
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 brick and stone need a sealant that suits them, at the right joint depth. Rainfall in the South East is lower than in much of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
For an older house near a landmark such as Church of St Michael, the joints between older walls, newer extensions and the roofline need a sealant that can move.
Finmere is about 4 miles west of Buckingham, in Buckinghamshire. Finmere gets the same service as everywhere we cover: old sealant removed completely, careful preparation and a 12-month guarantee. Finmere is one of 263 towns and villages in Buckinghamshire where we work for external mastic. For nearby work, see our Oxford page, about 18 miles away.
We work across MK18 for external mastic and the streets around it. If you need external mastic at a property on Chinalls Close, Stable Close and Fulwell Road or a nearby road, we can help. We also 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). We also work in nearby towns such as 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).
Local landmarks in Finmere
A little further out are The Menagerie (3.6 miles north-east) and Buckingham Community Hospital (3.9 miles east). For a walk, there’s Buckingham Sand Pit.
What we do, step by step
When we arrive, we look over the joints with you first. We protect the surfaces around the joints before any work begins. The work generally takes a few hours for a handful of joints, longer for a whole elevation. For a village or hamlet like Finmere, the journey is planned in advance: tell us about narrow lanes, gates, long drives and where we can park. Everything for the job comes with us, so a second trip is avoided where possible.
- We start by checking each joint, agreeing the ones to redo and how we will reach them.
- We cut out the failed sealant and rake out any dirt or growth.
- We clean both faces of the joint and prime them where the product calls for it.
- We push in closed-cell backing rod so the sealant is the right depth and bonds to the sides only.
- We gun in a flexible exterior sealant in a colour that suits the wall and tool it neatly.
Before we arrive
- Move anything stored near the joints
- On commercial sites, let us know about site rules
- Let us know about parking restrictions
Getting a quote
For external mastic in Finmere, call 0345 464 0079 or email us. Tell us what the problem is and where, and we will agree the price before any work begins.
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What the job involves on each surface
Brickwork movement joints
Clay brickwork grows slightly over its life and moves with the weather. The movement joint takes that up, so its sealant has to stay flexible.
Copings and trims
Metal and stone copings both move with temperature, so the joints need a sealant that stays flexible year round.
Work for landlords, hotels and businesses
Letting agents and landlords in Finmere can book us as well as homeowners. Resealing between tenancies is a simple way to keep a property in good order.
We also work for property managers and facilities teams in Finmere and across Buckinghamshire. Several sites can go on one quote, and we are fully insured.
Finmere questions
Will you come out to Finmere?
Yes, we do. We work across London and the South East, and smaller places are part of that. Longer journeys are simply planned in advance.
What guarantee comes with external mastic in Finmere?
All our work, in Finmere and everywhere else, comes with a 12-month guarantee. We’re also fully insured and ARBOMaster approved.
Can a movement joint be filled with mortar?
No. A mortar-filled joint can’t move, so the wall cracks somewhere else instead. It needs a flexible sealant over backing rod.
Should I try DIY first?
Sometimes. The key is preparation: remove all the old material and work on a clean, dry joint. We can always put it right if it fails.
How much does external mastic cost in Finmere?
Every job is different, so each one gets its own quote. To get one, call 0345 464 0079 or drop us an email and let us know what needs doing and where.
Can you seal over the old sealant?
No. We remove every bit of old sealant first, so the new sealant bonds properly.
What is backing rod for?
Closed-cell backing rod sets the depth of the sealant and stops it sticking to the back of the joint. That way it bonds to the two sides only and can stretch.
Will it make a mess?
Very little: the area around the joints is protected first, and we tidy up before we go.
DIY versus a professional finish
A DIY attempt doesn’t rule out a professional job. We remove it and do the joint properly.
Some sealant jobs are within reach of a careful DIYer, such as a straightforward joint indoors. The common mistakes are sealing over old sealant, sealing a damp joint and using far too much.
What we are called out for in Finmere
UV, rain and frost all age exterior sealant. In time it goes hard, crazes on the surface and stops stretching, so the joint eventually tears or comes away from one side.
The problems people generally mention when they call are:
- Joints with sealant missing in places
- Failed sealant between panels on a façade
- Damp patches traced to an open external joint
- Hard, crazed mastic that has stopped moving
Managing a site like Finmere Church of England Primary School? Then movement joints, cladding joints and gutters on larger buildings need the same care as a house’s.
What your quote should include
- Whether the sealant suits the joint
- Whether VAT is included
- When the joint can take water or movement
- Which colour the sealant will be