Buckinghamshire · England
External Mastic in Lower North Dean
We cover Lower North Dean for sealing brickwork movement joints, render, cladding and façade joints. Old sealant removed completely, joints prepared properly and every job guaranteed for a year.
- Movement joints filled with mortar instead of sealant
- Gaps where render, brick and frames meet
- Water getting into walls through failed joints
External mastic in Lower North Dean
Ground-floor and low-level joints are straightforward to reach. Where joints are higher up, tell us about the building when you get in touch and we will confirm what’s needed to reach them safely. We work on brickwork movement joints, render & cladding joints and concrete & block, and common reasons people get in touch are failed seals between different materials and rain getting behind render or cladding at a joint.
In a village or hamlet like Lower North Dean, older cottages and farm buildings often stand in the open, where walls and rooflines take the weather head on. Gutter joints and wall joints there need a sealant that can flex and stay put.
Whatever the size of the job, it’s backed by our one-year guarantee in Lower North Dean and across Buckinghamshire.
- Location
- Lower North Dean (HP14)
- Region
- Buckinghamshire
- Cover
- One year on every job
- Quotes
- Quoted before any work starts
- Call
- 0345 464 0079
- Updated
- 26 October 2026
Different surfaces, different methods
Brickwork movement joints
Vertical joints in long brick walls let the brickwork expand without cracking. They’re resealed over backing rod with a low-modulus sealant coloured to suit the wall.
Concrete and blockwork
The face of concrete or block is often dusty, so cleaning and priming matter. A primer goes on where the product requires one before the bead.
DIY versus a professional finish
What a professional job adds is preparation and the right product. Joints are cleaned back to sound surfaces and dried, and the sealant is chosen for how the joint moves and where it is.
If you’ve already had a go yourself, that’s fine. We cut it out and start again.
Common problems we fix in Lower North Dean
If plants are growing out of a joint, the sealant has usually failed or was never there. Dirt and roots then trap moisture in the joint.
The most common problems we see are:
- Damp patches traced to an open external joint
- Sealant pulling away from one side of the joint
- Brick movement joints where the sealant has split
- Gaps where render, brick and frames meet
If you let a flat or house near Saunderton station, split movement joints are easy to miss on a rental until damp shows inside.
What to look for in a quote
- What the cure time is
- How hidden problems are handled
- How the joint is cleaned and prepared
- Whether you can choose the colour
Quotes for external mastic in Lower North Dean
Your quote is based on your job. We look at:
- How easy the joints are to reach
- The number and length of the joints
- The type of sealant required
- Whether there’s mould to deal with
Doing several joints on one visit generally makes better use of the time than several visits, so it’s worth mentioning everything you’d like done. We’ll send you a clear quote for the lot.
Asking for a quote
Before you ask for a quote, have a think about:
- How many joints, rooms or windows are involved
- Any previous sealing or DIY work
- The type of property
- The address or postcode of the job
There’s no standard price list, because every job is different. Instead, we give you a clear quote for your job. To get started, call 0345 464 0079 or drop us an email.
Nearby places to Lower North Dean
Other services in Lower North Dean
When it isn’t the sealant
Sealant isn’t the answer to every problem, and we’d rather say so up front. It won’t solve:
- Damp that isn’t coming from the joint
- Adding movement joints to masonry that has none
- Failed render or damaged cladding panels
If you’re not sure, just phone 0345 464 0079 or drop us an email and we will give you a straight answer before booking.
Joints and surfaces we work on
- Render & cladding joints
- Concrete & block
- Joints between brick and frames
- Brickwork movement joints
- Copings & trims
- Façade panels
The process
There’s no need to move everything out before we come, only the area right around the joints. We protect the rest, and the work takes a few hours to a few days, depending on the length of joint and the access in most cases. In a small place like Lower North Dean, access is generally the main thing to plan. If the job is outside, mention outbuildings, exposed walls and how to reach them.
- Each joint is checked and the colour of the new sealant agreed.
- We take out the old sealant until the faces are sound.
- Backing rod goes in so the sealant can stretch between the two faces.
- We prime the faces where required.
- We gun in low-modulus sealant and tool it neatly.
How to prepare
- Plan for the work area to be out of bounds to pets and children
- Move anything stored near the joints
- Where the joints are inside, avoid wetting them before we arrive
Get a quote
If you are in Lower North Dean and need external mastic, ring 0345 464 0079 or email us. Tell us what the problem is and where, and we will agree the price before any work begins.
Read more
Why deal with it now?
A low-modulus sealant is chosen because it moves without pulling hard at the edges. That protects surfaces like brick, render and concrete. A stiffer product can damage the joint edge as it fails. Older cottages and farmhouses around Lower North Dean can have timber floors and frames, where water from a failed joint can cause rot if it’s left.
Leaving a failed joint usually makes the job bigger, not smaller, as water and mould keep getting in. If you’re unsure, phone 0345 464 0079 or drop us an email for an honest opinion and a quote.
Why choose Mr Mastic in Lower North Dean
- We agree the colour with you first
- Quality sealants from Arbo and Everbuild
- A sealant colour to suit the surroundings
- White, clear, grey or another colour, product permitting
FAQs for Lower North Dean
Do you work for landlords with property near Saunderton station?
Yes, landlords and agents are among the people we work for. You can ring 0345 464 0079 or send us an email with the details for a clear quote.
Do you cover smaller places like Lower North Dean?
Yes, we do. We work across London and the South East, and smaller places are part of that. The journey is planned ahead, so it helps to know about access.
Is it OK to fill a movement joint with cement?
No. Rigid materials can’t move with the wall, so the joint stops doing its job. If it has already been filled, we can generally cut it out and reseal it.
Do you guarantee your work?
Yes. Each job is guaranteed for twelve months, wherever you are.
How do I get a quote for external mastic in Lower North Dean?
The cost depends on the size of the job, access and how much old sealant has to come out. Ask us for a quote and we will talk you through it.
Do I have to be there?
We need access to the joints, so we will agree that with you when we book. For inside work, that normally means someone being in.
Is it worth trying it myself?
Some simple jobs can be done by a careful DIYer. The usual mistakes are sealing over old sealant, sealing a damp joint and using too much.
Where are you based?
We’re a Crawley-based firm, with over 20 years’ experience. Our area covers South East England, London and Scotland.
What external mastic looks like in Lower North Dean
Historic houses like Hughenden Manor (about 1.8 miles south) are a reminder that the area around Lower North Dean 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. 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.
For an older house near a landmark such as Speen Church (Baptist), older walls, gutters and the joints where extensions meet them need a flexible sealant. For site and facilities teams at buildings such as Hughenden Primary School, larger buildings have long runs of movement joint that eventually need resealing.
Lower North Dean is about 3 miles north of High Wycombe, in Buckinghamshire. Whether you are in the middle of Lower North Dean or further out, we cover external mastic for every kind of property, from flats and houses to offices and hotels. Our area takes in 263 places across Buckinghamshire, large and small. For nearby work, see our Reading page (18 miles or so).
We work across the HP14 postcode area for external mastic. Other places close to Lower North Dean include Upper North Dean (1 mile north-west), Naphill (1 mile south-west), Hughenden Valley (1 mile south-east), Bryant's Bottom (1 mile north) and Walter's Ash (1 mile west). Within a short drive, we also cover Aylesbury (10 miles north), High Wycombe (3 miles south), Chesham (7 miles east), Marlow (7 miles south), Amersham (7 miles east) and Beaconsfield (7 miles south-east).
What’s near Lower North Dean
Typical jobs here are in homes near Pipers Corner School and The Harrow pub. The nearest railway station is Saunderton station, roughly 2.5 miles west. A little further out are Eden (3.3 miles south) and Chiltern Hospital (3.3 miles east). Not far away are Prestwood Local Nature Reserve.