Buckinghamshire · England
External & façade joints in Flackwell Heath, Buckinghamshire
Professional external mastic in and around Flackwell Heath, with old sealant always removed completely.
- Damp patches traced to an open external joint
- Plants rooting in failed movement joints
- Rigid filler in a joint that should flex
How the job changes by surface
Concrete and blockwork
Blockwork and concrete shrink over time and move with the seasons. Their movement joints are sealed over backing rod with a flexible sealant.
Copings and trims
Metal and stone copings both move with temperature, so the joints need a sealant that stays flexible in all weathers.
External mastic for homes and businesses in Flackwell Heath
Short cuts in external joints show up within a season or two. Overfilled joints, missing backing rod and sealant laid over old sealant rarely last long. We strip the joint back and start again. If you have plants rooting in failed movement joints and water getting into walls through failed joints, we can help, whatever the surface.
In a smaller place like Flackwell Heath, some homes face open ground, and walls and rooflines facing the weather take the worst of it. That is where gutter joints and wall joints tend to fail first.
The work is covered for a year after we finish. If anything is not right with it, ring 0345 464 0079 or send us an email.
- Where
- Flackwell Heath (HP10)
- Wider area
- Buckinghamshire
- Cover
- A year, on every job
- Quote
- A clear price before any work starts
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
What sealant work cannot fix
We’d rather tell you now than do work that will not last, so here’s what sealant cannot put right:
- Walls that need new movement joints cut into them
- Structural movement, which needs a surveyor or engineer
- Rising or penetrating damp from elsewhere in the wall
If you’re not sure, just ring 0345 464 0079 or drop us an email and we’ll give you a straight answer before you book.
Surfaces we seal
- Copings & trims
- Joints between brick and frames
- Render & cladding joints
- Façade panels
- Brickwork movement joints
- Concrete & block
What happens on the day
When we arrive, we look over the joints with you first. We protect the surfaces around the joints before work begins. Most jobs take a few hours for a handful of joints, longer for a whole elevation. A visit to Flackwell Heath is planned like any other: the time, the access and where to park are agreed in advance. Outdoor jobs depend on a dry day, since sealant needs a dry surface.
- First, the joints are inspected and the access agreed.
- Every bit of old sealant and any mortar or debris is cut out.
- The faces are brushed clean and primed where the product requires it.
- We fit closed-cell backing rod to control the depth.
- The exterior sealant is applied, tooled and checked along its length.
Preparing for the visit
- Mention any tricky access
- For indoor joints, keep the area dry beforehand if you can
- Tell us about any previous sealing or DIY attempts
Get a quote
Want a quote for external mastic? Please call 0345 464 0079 or send us an email with a few details. We will explain what we’d do and give you a clear quote before any work starts.
Related advice
Can I do it myself?
The biggest DIY mistake is sealing over old sealant. Silicone does not stick to old silicone, so it lifts and traps water and mould underneath. All the old material has to come out first.
A careful DIYer can reseal a simple joint, such as a straightforward joint indoors. The common mistakes are sealing over old sealant, sealing a damp joint and using far too much.
What affects the cost of external mastic
Jobs vary more than people expect. What affects the quote:
- Whether old sealant or filler has to be cut out
- The product the joint needs
- Any working-time requirements on site
- The size of the job
Rather than a set price list, we look at what your job involves: the amount of work, the old material and the access. The price is agreed before we begin.
Asking for a quote
The more you tell us, the more accurate the quote. When you get in contact, it helps to mention:
- The address or postcode of the job
- How many joints, rooms or windows are involved
- If someone has resealed it before
- The problem you’ve noticed
For external mastic in Flackwell Heath, call 0345 464 0079 or send us an email. A short description of the job and where it is helps us quote, and you will get a clear quote before work begins.
What external mastic looks like in Flackwell Heath
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. With historic houses such as Cliveden (about 2.9 miles south) nearby, there’s older building stock in the area around Flackwell Heath 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.
If you let a flat or house near Bourne End station, failed wall and movement joints let damp in, so they’re worth checking between tenancies. For site and facilities teams at buildings such as Juniper Hill School, larger buildings have long runs of movement joint that eventually need resealing. In the older streets around Christ Church, the joints between older walls, newer extensions and the roofline need a sealant that can move.
Flackwell Heath is about 3 miles west of Beaconsfield, in Buckinghamshire. Flackwell Heath gets the same service as everywhere we cover: old sealant removed completely, careful preparation and a 12-month guarantee. Flackwell Heath is one of 263 places in Buckinghamshire where we work for external mastic. For nearby work, see our Reading page, about 16 miles away.
Postcode districts we cover here for external mastic: HP10. Whether your property is on Clay Close, Hedley Road and Cherrywood Gardens or anywhere close by, we can help. We also cover Well End (1 mile south-west), Fern (1 mile south-west), Bourne End (1 mile south), Coldmoorholme (1 mile south-west) and Cores End (1 mile south). Larger places within reach include High Wycombe (3 miles north-west), Chesham (9 miles north-east), Marlow (3 miles south-west), Amersham (7 miles north-east), Beaconsfield (3 miles east) and Chalfont St Peter (6 miles east).
Landmarks near Flackwell Heath
Around Flackwell Heath, our work takes us to homes and buildings near The Happy Union pub and Bourne End Academy and the streets around them. The nearest railway station is Bourne End station, about 1.5 miles south of the centre. A little further out are Hospital of St John the Baptist (2.5 miles north-west) and Chiltern Sound Phonograph Museum (3.5 miles south-west). Green spaces nearby include Holtspur Bank.
Questions from Flackwell Heath
Is Flackwell Heath within the area you cover?
Yes, we do. We work across London and the South East, from towns to the smallest places. The journey is planned ahead, so it helps to know about access.
Can you do external mastic in Flackwell Heath?
Yes, Flackwell Heath is within the area we cover. We work across London and the South East. You can call 0345 464 0079 or send us an email and tell us what needs doing.
Do you take out the old sealant first?
Always. Sealing over old sealant is the main reason resealing fails early, and it’s something we never do.
How long should I leave it?
Cure times vary by product and the conditions. We tell you how long to leave it before we go.
Can you seal joints between two different materials?
Yes. We cut out the old sealant, prepare both faces and reseal with a flexible exterior product. The colour is chosen to suit.
Where are you based?
We are a Crawley-based firm, with over 20 years’ experience. We work across South East England, London and Scotland.
Is it OK to seal over old sealant?
No. New silicone won’t bond to old silicone, and it traps any mould or water underneath. It all has to come out first.
What sealant do you use?
It depends on the joint: anti-fungal sanitary silicone in wet areas, and other sealants where joints move or face the weather. Brands we use include Arbo and Everbuild.
Aftercare tips
Joint life depends on how it’s used and looked after. We suggest:
- Get split or bare joints resealed while the damage is small
- Make sure movement joints are not pointed over
- Show decorators and builders where the movement joints are
- Clear growth from the base of walls and joints
Keep the joints clear of soil, plants and climbing growth. Anything that holds water against the joint wears it out sooner.
Act while the splits are small. At that stage it’s a simple cut out and reseal.
Why deal with it now?
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. Homes in smaller places like Flackwell Heath can face more weather, and failed outside joints let damp into walls. Inside, a split seal lets water into floors and panels just as it would anywhere.
No two jobs are quite the same, so each one gets its own quote. Size, access and the product the joint needs all make a difference, and we’ll explain the quote if you ask.
Why choose Mr Mastic in Flackwell Heath
- Homes, businesses and hotels
- Every job guaranteed for a year
- We never seal over old sealant
- Colour picked to suit the job
Read what affects the cost and customer reviews.