Buckinghamshire · England
External & façade joints in Shalstone, Buckinghamshire
External mastic in Shalstone from a team with over 20 years’ experience. Rated 4.9 on Google from 180+ five-star reviews.
- Weathered mastic that no longer stretches
- Damp patches traced to an open external joint
- Cracked joints where brick meets render or frames
About our external mastic in Shalstone
For buildings in Shalstone, we reseal external joints of all kinds, from brick movement joints to cladding panels. The preparation is the same whatever the wall: clean, sound faces and a controlled depth. We’re often asked to deal with joints where the bead has come unstuck and brick movement joints where the sealant has split, on copings & trims, concrete & block and render & cladding joints.
Around Shalstone, 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.
All our work is covered by a 12-month guarantee.
- Where
- Shalstone (MK18)
- Region
- Buckinghamshire
- Guarantee
- A year, on every job
- Price
- A clear price before work begins
- Phone
- 0345 464 0079
- Updated
- 26 October 2026
Why it’s worth doing now in Shalstone
A properly done movement joint is an even line in a colour that suits the wall. A hurried job with smeared edges and no backing looks worse and fails sooner, so it pays to do it properly once. Around Shalstone, older homes often have timber in their floors and frames, where water from a failed joint can cause rot if it’s left.
Doing several joints on one visit usually makes better use of the time than several visits, so tell us about everything that needs sealing. You’ll get one clear quote for the whole job.
Why choose Mr Mastic in Shalstone
- A choice of colours where the product allows
- Over 20 years’ experience
- Domestic, commercial and hotel work
- Arbo and Everbuild products
What affects the cost of external mastic
Call for a quick quote. What matters most is:
- The number and length of the joints
- The number of rooms or windows
- Whether there’s mould to deal with
- The old material and how stubborn it is
Commercial jobs are quoted on the same basis as homes: the amount of work, the access and the products needed, plus any working-time requirements on site. Ask us for a quote and we will go through it with you.
Asking for a quote
When you contact us, it’s useful to know:
- The type of property
- Pictures of the joints, sent by email
- What the problem is, such as mould, gaps, leaks or cracking
- Whether it has been sealed before
Need a quote? Please call 0345 464 0079 or drop us an email and tell us about the job. We’ll explain what we’d do and give you a clear quote before we start.
Surface by surface
Concrete and blockwork
The face of concrete or block is often dusty, so preparation is key. A primer goes on where the product requires one.
Copings and trims
Coping and trim joints face rain and sun head on. We reseal them with an exterior sealant suited to the material.
What sealant work cannot fix
We’d rather tell you now than do work that will not last, so these are the limits:
- Cutting new joints into brickwork, which is building work rather than sealant work
- Damp that isn’t coming from the joint
- Loose or hollow render, which needs re-rendering
If in doubt, call 0345 464 0079 or email us and we will say what we think before booking.
Surfaces we seal
- Copings & trims
- Façade panels
- Concrete & block
- Joints between brick and frames
- Brickwork movement joints
- Render & cladding joints
What external mastic looks like in Shalstone
With historic houses such as Stowe House (about 2 miles east) nearby, there’s older building stock in the area around Shalstone as well as newer homes. Where a home is older, older brick and stone need a sealant that suits them, at the right joint depth. The South East is one of the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
In and around Shalstone, as anywhere, good external mastic starts with a clean, dry, properly prepared joint.
Shalstone is in Buckinghamshire. We provide external mastic to homeowners, landlords and businesses in Shalstone and nearby. Shalstone is one of 263 towns and villages in Buckinghamshire where we work. For nearby work, see our Oxford page, about 20 miles away.
Work in MK18 works the same way as everywhere else we cover. We also cover the places around Shalstone: Water Stratford (2 miles south), Dadford (2 miles north-east), Radclive (3 miles south-east) and Chackmore (3 miles east). Larger places within reach include Buckingham (4 miles south-east), Winslow (10 miles south-east), Steeple Claydon (7 miles south-east), Tingewick (3 miles south), Whitchurch (14 miles south-east) and Quainton (12 miles south-east).
Landmarks near Shalstone
A little further out are Beaumont Castle (2.6 miles south-west) and The Menagerie (2 miles east). Not far away are Buckingham Sand Pit.
Your questions about external mastic in Shalstone
What guarantee comes with external mastic in Shalstone?
All our work, in Shalstone and everywhere else, comes with a 12-month guarantee. We are fully insured, and an ARBOMaster approved applicator.
Will you come out to Shalstone?
Yes, Shalstone is covered. Our work covers London and the South East, from towns to the smallest places. The journey is planned ahead, so it helps to know about access.
Do you work at height?
It depends on the building. Send us pictures and a rough idea of the height and we’ll confirm how they can be reached safely.
How long does external mastic take?
Most jobs take a few hours to a few days, depending on the length of joint and the access, including preparation and clearing up. We’ll confirm how long when we quote.
What is a movement joint?
A movement joint is a planned break in the wall that absorbs expansion and shrinkage. It should be filled with flexible sealant, never mortar.
What sealant do you use?
Products from Arbo and Everbuild, among others, picked for each joint. We’ll tell you what we’re using and why.
Do you do commercial work?
Yes. We have worked for hotels, offices and other businesses, and we are fully insured.
Why do you put foam in the joint first?
Backing rod controls the sealant depth and keeps it off the back of the joint. Then the sealant bonds to two faces and can move.
Do you need external mastic in Shalstone?
Weeds, moss and debris in a joint are a sign the sealant has gone. Roots and dirt hold water against the wall and make things worse.
Look out for these signs:
- Panel joints letting water in
- Brick movement joints where the sealant has split
- Damp patches traced to an open external joint
- Movement joints filled with mortar instead of sealant
If you live in an older home near Church of St Edward, old and new materials meet at the roofline and walls, which is where sealant earns its keep.
Before you book anyone
- Who turns up on the day
- Whether they’re fully insured
- What happens if they find a problem under the old sealant
- How long to leave it before use
Looking after it afterwards
Joint life depends on how it’s used and looked after. We suggest:
- Make sure movement joints are not pointed over
- Keep soil, plants and ivy away from the joints
- Tell anyone working on the walls about the movement joints
- Ask before painting over external sealant
Do not paint over the new sealant unless we have said the product is paintable. Paint can crack on a flexible joint and spoil the finish.
A joint that has stopped moving pushes the movement elsewhere, normally as cracking in the brickwork or render nearby. Resealing it early helps prevent that.
What we do, step by step
At the end, we look at the finished work together and explain the cure time. The work normally takes a few hours for a handful of joints, longer for a whole elevation, depending on the size of the job. In a small place like Shalstone, access is generally 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.
- A low-modulus exterior sealant is gunned in and tooled to a neat finish.
Getting ready for the visit
- Let us know if you’ve seen damp or leaks
- Mention any parking rules near the property
- Where the joints are inside, avoid wetting them before we arrive
Get a quote
If you are in Shalstone and need external mastic, ring 0345 464 0079 or send us an email. Tell us what the problem is and where, and we will agree the price before any work begins.