Buckinghamshire · England
External Mastic in Dinton
External mastic for Dinton and the surrounding area: careful preparation, the right product and tidy work. Ask us for a quick quote.
- Panel joints letting water in
- Movement joints filled with mortar instead of sealant
- Old sealant gone brittle and cracked
Signs you need external mastic in Dinton
Poor preparation causes many early failures: joint faces that were dusty or damp, unprimed where they needed it, or still carrying old sealant. The new sealant then lets go long before it should.
Common reasons people contact us include:
- Rigid filler in a joint that should flex
- Sealant pulling away from one side of the joint
- Leaking joints around cladding and façade panels
- Weeds or debris growing in open joints
If you let a flat or house near Haddenham & Thame Parkway station, outside joints that have cracked can let damp into a rental, so check them between lets.
What to look for in a quote
- What the quote includes, VAT included or not
- Who does the work, and how experienced they are
- How long to leave it before use
- The length of the guarantee
External mastic in Dinton, done properly
Getting the depth right is half the job. Backing rod controls how deep the sealant goes and keeps it off the back of the joint, leaving it bonded to two faces so it can move with the wall. We’re often asked to deal with sealant pulling away from one side of the joint and joints pointed up with cement by mistake, on façade panels, brickwork movement joints and copings & trims.
Around Dinton, older buildings can be stone, brick or timber-framed, many with extensions added later. Where one material meets another is where water generally gets in, and they need the right sealant at the right depth.
All our work is covered by a 12-month guarantee.
- Where
- Dinton (HP17)
- Wider area
- Buckinghamshire
- Cover
- A year, on every job
- Price
- Quoted before any work starts
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
Leave it or put it right?
An open joint keeps letting water into the wall with every downpour. Wet masonry is more easily damaged by frost, so the problem grows beyond the joint itself. Older cottages and farmhouses around Dinton can have timber floors and frames, and water through a failed joint can rot timber if it’s left.
Doing several joints on one visit normally makes better use of the time than several visits, so tell us about everything that needs sealing. We’ll send you a clear quote for the lot.
Why choose Mr Mastic in Dinton
- A 12-month guarantee on all work
- We never seal over old sealant
- Rated 4.9 stars on Google
- Domestic, commercial and hotel work
FAQs for Dinton
Do you work for landlords with property near Haddenham & Thame Parkway station?
Yes, landlords and agents are among the people we work for. Just phone 0345 464 0079 or email us with the address and what needs doing, and we will send you a clear quote.
Will you come out to Dinton?
Yes, we do. Our work covers London and the South East, from towns to the smallest places. Longer journeys are simply planned in advance.
How do you reach high-level joints?
It depends on the height and the site. Ground-floor joints are simple; for higher ones, send details and we will confirm the access.
What does external mastic cost?
There’s no set price, as it depends on the job: its size, the old material, access and the product needed. We agree the price before any work begins.
Will the old sealant be removed?
Yes. Sealing over the old bead is the commonest cause of early failure, so we never do it.
How long does the job take?
As a guide, most jobs take anything from a few hours to several days, depending on the building. Bigger jobs take longer, and we will say how long yours will take.
Are you insured?
Yes. We’re fully insured, and we’ve been doing sealant work for more than 20 years.
Do you do commercial work?
Yes. Hotels, offices and other businesses use us, and we are fully insured.
How we quote for external mastic
Every job gets its own quote. This is what makes a difference:
- The type of sealant required
- How many rooms, windows or areas are involved
- The number and length of the joints
- The old material and how stubborn it is
What it costs depends on the size of the job, how hard the old material is to remove and access to the work. We give a clear quote before any work starts, so you know where you stand.
What to tell us for a quote
A few details help us give you an accurate quote. When you ask for a quote, tell us:
- The address or postcode of the job
- Roughly how big the job is
- Access, such as stairs, a lift or height
- If someone has resealed it before
We quote each job on its own, so the first step is telling us about yours. Just call 0345 464 0079 or email us with the details.
When it is not the sealant
A few problems are outside what sealant work can do:
- Render that’s blown, hollow or coming away
- Cracking across the wall rather than at a joint
- Damp that isn’t coming from the joint
Not sure which it is? You can phone 0345 464 0079 or email us and we will tell you honestly.
Surfaces we seal
- Façade panels
- Brickwork movement joints
- Concrete & block
- Copings & trims
- Render & cladding joints
- Joints between brick and frames
How the visit works
Good joint work is mostly preparation, so that’s where we spend the time. Every joint is cleaned and dried before new material goes in. In total, it generally takes a few hours to a few days, depending on the length of joint and the access. In a small place like Dinton, access is usually the main thing to plan. For outside work, also let us know about exposed walls and any outbuildings involved.
- Each joint is checked and the colour of the new sealant agreed.
- We take out the old sealant until the faces are sound.
- Closed-cell backing rod is pushed in so the sealant bonds to two sides only.
- Primer is applied wherever the sealant needs it.
- We gun in low-modulus sealant and tool it neatly.
Before we arrive
- On commercial sites, let us know about site rules
- Mention if the joints have been sealed before
- Let us know about parking restrictions
Getting a quote
Asking for a quote is easy: tell us what needs doing and where, and roughly how big it is. Photos by email help us understand the job.
Read more
Can I do it myself?
A DIY attempt does not 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.
Looking after it afterwards
Once the sealant has cured, a few habits help it last:
- Look over the joints every year, ideally after winter
- Don’t let climbing plants root in the sealant
- Avoid pressure-washing directly into sealant joints
- Check the sealant is paintable before painting near it
Make sure anyone working on the wall later knows where the movement joints are. They must stay as flexible joints, never rendered or pointed over.
If you can see gaps, plants or bare sections in a joint, have it checked. Early work is quicker and leaves a better finish.
External mastic in Dinton: local notes
Historic houses like Waddesdon Manor (about 4 miles north-west) are a reminder that the area around Dinton has older buildings as well as new. In older buildings, older walls and rooflines need a sealant that moves with them and suits the material. London and the South East are among the drier parts 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 Church of Saints Peter and Paul, the joints between older walls, newer extensions and the roofline need a sealant that can move.
Dinton is about 4 miles south-west of Aylesbury, in Buckinghamshire. Every kind of property in Dinton can book us for external mastic, old or new, large or small. The work is guaranteed for a year. Dinton is one of 263 towns and villages in Buckinghamshire where we work for external mastic. We also work in Oxford, about 15 miles from Dinton.
Postcode districts we cover here for external mastic: HP17. Local streets include High Street, Stars Lane and New Road, and we cover them all. We also cover the places around Dinton: Upton (1 mile north-east), Ford (1 mile south-east), Sedrup (2 miles east), Bishopstone (3 miles east) and Ilmer (3 miles south). Further out, we also cover Aylesbury (4 miles north-east), High Wycombe (13 miles south-east), Chesham (13 miles south-east), Buckingham (15 miles north), Amersham (15 miles south-east) and Elmhurst (4 miles north-east).
Near you in Dinton
Locally, jobs take us to homes and businesses close to The Seven Stars Public House and the streets around them. The nearest railway station is Haddenham & Thame Parkway station, about 2.4 miles south-west. A little further out are Roald Dahl Children's Gallery (3.9 miles north-east) and Dinton Castle (0.5 miles north). The countryside around Dinton includes Snakemoor.