Buckinghamshire · England
External Mastic in Chesham Bois
External mastic for Chesham Bois, by sealant specialists with 20+ years’ experience. Rated 4.9 on Google from 180+ five-star reviews.
- Leaking joints around cladding and façade panels
- Gaps where render, brick and frames meet
- Movement joints with cracked, split or missing sealant
How we handle external mastic in Chesham Bois
Where two different materials meet, such as brick and render or blockwork and metal, they move at different rates. A flexible sealant bridges the two. If you have hard, crazed mastic that has stopped moving and failed sealant between panels on a façade, we can put it right, whatever the surface.
In and around Chesham Bois, older properties sit alongside newer ones, each with its own outside joints. Older gutters and trims need their joints resealed; newer brick and render need their movement joints kept sound.
Our work is backed for twelve months, and the guarantee is the same wherever you are.
- Place
- Chesham Bois (HP6, HP5)
- Wider area
- Buckinghamshire
- Cover
- A year, on every job
- Quote
- A clear price before work begins
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
Your questions about external mastic in Chesham Bois
Is Chesham Bois within the area you cover?
Yes, we do. Our work covers London and the South East, and smaller places are part of that. The journey is planned ahead, so it helps to know about access.
Can you do external mastic in Chesham Bois?
Yes. Our work covers London and the South East, and Chesham Bois is part of that. You can phone 0345 464 0079 or send us an email and tell us what needs doing, and we will give you a clear price.
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.
Do you work for landlords and businesses?
Yes, often. We can quote for several properties at once.
How long does external mastic take?
Typically it takes anything from a few hours to several days, depending on the building. Larger jobs naturally take longer, and we will tell you how long to expect.
Do you guarantee your work?
Yes. Each job is guaranteed for twelve months.
Is it OK to seal over old sealant?
No, because it fails. We remove every bit of old sealant first, so the new sealant bonds properly.
Where do you work from?
Our base is in Crawley, and we work across South East England, London and Scotland.
Should I try it myself first?
A careful DIYer can reseal a simple joint, like a short, easy-to-reach joint indoors. The common mistakes are sealing over old sealant, sealing a damp joint and using far too much.
A DIY attempt doesn’t rule out a professional job. We cut it out and start again, so just mention it when you contact us.
What happens if it’s left?
Sealing over the top of old mastic doesn’t hold for long. The new layer can’t bond properly to old, weathered material, so we always take the old sealant out. In an older home around Chesham Bois, damp from a failed joint can get into timber and plaster, and that’s a much bigger job than renewing the sealant.
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 the work is at height. We take all of that into account in your quote.
Why us?
- Domestic, commercial and hotel work
- Sanitary silicone with an anti-fungal additive in wet areas
- We agree the colour with you first
- 20+ years of sealant experience
Take a look at what affects the cost or customer reviews.
What affects the quote in Chesham Bois
Every job gets its own quote. This is what makes a difference:
- The type of sealant required
- When we can work, for business premises
- Mould in or behind the old joints
- Access and height
Every job is a little different, so we quote each one individually. The number of joints, how easy they are to reach and the sealant needed all make a difference.
Helping us quote
To make quoting easier, please include:
- How we’d reach the joints
- The type of property
- The address or postcode of the job
- What’s wrong with the joints now
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.
Also near Chesham Bois
What else we do in Chesham Bois
Work for landlords, hotels and businesses
Housing providers, facilities teams and property managers book us too. Several sites can be quoted together, and we’re fully insured for the work.
Failed sealant is one of the commonest items on a check-out report. We can quote for more than one property at once.
Outside joints around Chesham Bois
Historic houses like Chenies Manor House (about 3.2 miles east) are a reminder that the area around Chesham Bois 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. 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.
Managing a site like Elangeni School? Then larger buildings have long runs of movement joint that eventually need resealing. Letting a property close to Amersham station? Then split movement joints are easy to miss on a rental until damp shows inside.
Chesham Bois is about 1 mile north of Amersham, in Buckinghamshire. If you need external mastic in Chesham Bois, it’s easy to get a quote: please phone 0345 464 0079 or drop us an email. We cover Buckinghamshire from our Crawley base. Chesham Bois is one of 263 places in Buckinghamshire where we work for external mastic. You can also see our page for Reading, about 23 miles away.
Our applicators cover all of HP6 and HP5 for external mastic and the streets around it. That includes homes and businesses on Bois Lane, Green Lane and North Road and the roads around them. Nearby, we also carry out external mastic in Amersham (1 mile south), Amersham on the Hill (1 mile south), Waterside (1 mile north), Hyde Heath (2 miles west) and Woodrow (3 miles south-west). Larger places within reach include Aylesbury (13 miles north-west), High Wycombe (7 miles south-west), Marlow (11 miles south-west), Beaconsfield (6 miles south), Chalfont St Peter (6 miles south) and Elmhurst (13 miles north-west).
Around Chesham Bois
Around Chesham Bois, our work takes us to homes and buildings near Dr Challoner's Grammar School, The Boot and Slipper pub and Home Tuition Service, among other places. The nearest railway station is Amersham station, about 0.8 miles south of the centre. Other landmarks nearby include Amersham Fair Organ Museum (0.6 miles south-east) and Amersham Hospital (1.7 miles south-west). For a walk, there’s Sands Bank.
When it isn’t the sealant
We’ll always be straight with you, so here’s what new sealant will not do:
- Render that’s blown, hollow or coming away
- Subsidence or other structural problems
- Cracks in the bricks or render themselves, away from the joints
If in doubt, call 0345 464 0079 or drop us an email and we’ll say what we think before you book.
Joints and surfaces we work on
- Copings & trims
- Joints between brick and frames
- Concrete & block
- Façade panels
- Render & cladding joints
- Brickwork movement joints
The process
When we arrive, we look over the joints with you first, so you know exactly what we’re doing. Surfaces next to the work are protected before work begins. The work generally takes a few hours to a few days, depending on the length of joint and the access. Parking around Chesham Bois is usually easier than in a town centre, but mention any lanes, gates or long drives. For outside work, side access and the height of the joints help us plan.
- We start by checking each joint, agreeing the ones to redo and how we will reach them.
- Old sealant and any debris are cut and raked out.
- We clean both faces of the joint and prime them where the product calls for it.
- Backing rod goes in next, setting the depth and keeping the sealant off the back of the joint.
- The new sealant, chosen to suit the brick or render, is applied and tooled to a neat finish.
Getting ready for the visit
- For business premises, tell us about site rules or sign-in
- Plan for the work area to be out of bounds to pets and children
- Mention any tricky access
Ask for a quote
For external mastic in Chesham Bois, phone 0345 464 0079 or drop us an email. A short description of the job and where it is helps us quote, and we will agree the price before any work begins.
Advice
Signs you need external mastic in Chesham Bois
Sunlight, wet weather and frost wear exterior sealant down. In time it goes hard, crazes on the surface and stops stretching, so the next time the wall moves, it splits or pulls away.
Keep an eye out for these signs:
- Hard, crazed mastic that has stopped moving
- Movement joints filled with mortar instead of sealant
- Sealant that has lost its bond to the brick or render
- Moss and dirt in joints with no sealant left
If you live in an older home near Church of St Leonard, older walls, gutters and the joints where extensions meet them need a flexible sealant.
Before you book anyone
- How the joint is cleaned and prepared
- Whether they’re fully insured
- Which colour the sealant will be
- What the quote includes, VAT included or not