Hertfordshire · England
Flaunden External Mastic
Sealing brickwork movement joints, render, cladding and façade joints for homeowners, landlords and businesses in Flaunden. Fully insured, ARBOMaster approved and guaranteed for a year.
- Brick movement joints where the sealant has split
- Panel joints letting water in
- Cracked joints where brick meets render or frames
Why it’s worth doing now in Flaunden
Pointing a movement joint with mortar might seem a neat fix, but it stops the joint moving. The wall then cracks somewhere else. A flexible sealant over backing rod is what the joint needs. Older cottages and farmhouses around Flaunden can have timber 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, any mould to treat, and whether we need extra access for height. Your quote takes all of that into account.
Why choose Mr Mastic in Flaunden
- Colour agreed with you before we start
- Trusted Arbo and Everbuild sealants
- Rated 4.9 stars on Google
- We leave the area clean and tidy
Read what affects the cost and customer reviews.
External mastic for homes and businesses in Flaunden
For buildings in Flaunden, we reseal external joints of all kinds, from brick movement joints to cladding panels. The preparation is the same whatever the wall: clean joint faces and the right depth. We work on copings & trims, joints between brick and frames and render & cladding joints, and common reasons people get in touch are damp patches traced to an open external joint and cracked joints where brick meets render or frames.
Around Flaunden, older buildings can be stone, brick or timber-framed, many with extensions added later. Where one material meets another is where water usually gets in.
Big or small, you get the same 12-month guarantee in Flaunden and across Hertfordshire.
- Location
- Flaunden (HP3)
- Region
- Hertfordshire
- Guarantee
- One year on every job
- Quote
- A clear price before work begins
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
What happens on the day
On the day, there’s very little for you to do. Show us the job and we’ll take it from there. The job generally takes a few hours for a handful of joints, longer for a whole elevation. For a village or hamlet like Flaunden, the journey is planned in advance: let us know about lanes, gates and parking. Everything for the job comes with us, so a second trip is avoided where possible.
- First we look over the joints with you, agree which to renew and talk through access.
- We cut out the failed sealant and rake out any dirt or growth.
- Both sides are cleaned back to sound material and primed if needed.
- We push in closed-cell backing rod so the sealant is the right depth and bonds to the sides only.
- A flexible exterior sealant is applied and tooled in a colour to suit the wall.
How to prepare
- Clear items away from the joints we are working on
- Mention any tricky access
- Keep children and pets away from the work area
How to get a quote
We do not publish a price list, because every job is different. Instead, we give you a clear price for your job. To get started, phone 0345 464 0079 or send us an email.
Read more
Towns and villages near Flaunden
More services for Flaunden
Aftercare tips
To keep the joints looking good and working properly:
- Avoid pressure-washing directly into sealant joints
- Deal with leaking gutters that soak the joints below
- Get split or bare joints resealed while the damage is small
- Show decorators and builders where the movement joints are
If you have more work done on the wall, such as new render, cladding or an opening, show the contractor the movement joints. They should be kept open and resealed, not filled.
Leaks behind façade panels and render often go unseen. When it finally shows inside, the joint may have been open for years, so it’s worth resealing at the first signs.
DIY sealant or a professional job?
Not every job suits DIY: work at height, external movement joints, fire-rated sealant and large areas call for the right materials, safe access and experience.
The difference is mostly in the preparation and the product. We take joints back to clean, dry surfaces, and the sealant is matched to the joint and its conditions.
Quotes for external mastic in Flaunden
Some jobs are bigger than they look, and some smaller. What affects the quote:
- Whether the work is at height
- Whether there’s mould to deal with
- The product the joint needs
- How much old sealant there is and how hard it is to remove
Rather than a set price list, we look at what your job involves: the amount of work, the old material and the access. You’ll know the price before we begin.
Asking for a quote
What to tell us when you ask for a quote:
- How we’d reach the joints
- What the problem is, such as mould, gaps, leaks or cracking
- Where the job is, and your postcode
- Roughly how big the job is
Want a quote for external mastic? Please ring 0345 464 0079 or drop us an email and tell us about the job. You’ll know what we plan to do, and what it will cost, before any work begins.
Work for landlords, hotels and businesses
Letting agents and landlords in Flaunden can book us as well as householders. Resealing between tenancies keeps a property looking cared for.
Businesses can book us for washrooms, kitchens, offices and more. On commercial sites, working times can be discussed when we quote.
Flaunden questions
Can you help a landlord with a rental near Chalfont & Latimer station?
Yes, landlords and agents are among the people we work for, and several properties can go on one quote. Just phone 0345 464 0079 or email us with the address and what needs doing, and we will give you a clear price.
Do you cover smaller places like Flaunden?
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.
Do I have to be there?
If the work is inside, we need someone to let us in. Once we have agreed the job, you do not need to watch us work.
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?
Always. Sealing over the old bead is the commonest cause of early failure, so we never do it.
Are you fully insured?
Yes. Full insurance covers our work, and we can confirm the details when we quote.
Can you seal over the old sealant?
No. We remove every bit of old sealant first, so the new joint bonds to clean surfaces.
What do you need from me for a quote?
Let us know what needs doing and where, plus photos if you have them. We will ask anything else we need to know.
Walls and rooflines in Flaunden
With historic houses such as Chenies Manor House (about 1.6 miles south) nearby, there’s older building stock in the area around Flaunden as well as newer homes. Where a home is older, older walls and rooflines need a sealant that moves with them and suits the material. The South East is one of the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
Letting a property close to Chalfont & Latimer station? Then outside joints that have cracked can let damp into a rental, so check them between lets. Homes close to Church of St Mary Magdalene (Church of England) include some older properties, and old and new materials meet at the roofline and walls, which is where sealant earns its keep. Schools such as St Clement Danes School are buildings too, and movement joints, cladding joints and gutters on larger buildings need the same care as a house’s.
Flaunden is about 3 miles north-east of Amersham, in Hertfordshire. If you need external mastic in Flaunden, it’s easy to get a quote: please phone 0345 464 0079 or email us. We cover Hertfordshire from our Crawley base, Flaunden included. Flaunden is one of 381 towns and villages in Hertfordshire we cover for external mastic. Our London page covers work nearby.
Jobs for external mastic in HP3 works the same way as everywhere else we cover. We also cover the places around Flaunden: Belsize (1 mile east), Chenies (1 mile south), Latimer (2 miles south-west), Little Chalfont (3 miles south-west) and Chorleywood (3 miles south). Within a short drive, we also cover Watford (6 miles south-east), Hemel Hempstead (5 miles north-east), St Albans (9 miles north-east), Harpenden (11 miles north-east), Hatfield (14 miles east) and Borehamwood (11 miles east).
Landmarks near Flaunden
Locally, jobs take us to homes and businesses close to The Green Dragon pub and the streets around them. Flaunden’s nearest station is Chalfont & Latimer station, roughly 2.4 miles south-west of the centre. A little further out are Amersham Fair Organ Museum (3.1 miles south-west) and Hemel Hempstead Hospital (4.5 miles north-east). For a walk, there’s Sarratt Bottom nature reserve.
When something else is needed
We will not take on work that will not last, so here’s what sealant cannot put right:
- Cracks in the bricks or render themselves, away from the joints
- Render that is blown, hollow or coming away
- Walls that need new movement joints cut into them
If you’re not sure, just call 0345 464 0079 or drop us an email and we’ll give you a straight answer.
Where we work in Flaunden
- Façade panels
- Render & cladding joints
- Copings & trims
- Concrete & block
- Brickwork movement joints
- Joints between brick and frames