Buckinghamshire · England
Amersham External Mastic
We cover Amersham for sealing brickwork movement joints, render, cladding and façade joints. Old sealant removed completely, joints prepared properly and a 12-month guarantee.
- Weathered mastic that no longer stretches
- Joints with sealant missing in places
- Movement joints filled with mortar instead of sealant
External mastic in Amersham, done properly
Movement joints let brickwork, render and cladding expand and shrink without cracking. Its sealant has to flex with the building, season after season, so once it splits or hardens, the joint stops working and water gets in. Typical jobs include leaking joints around cladding and façade panels and brick movement joints where the sealant has split, on concrete & block, render & cladding joints and joints between brick and frames.
In a town like Amersham, older houses with traditional gutters sit alongside newer estates with uPVC rooflines and rendered walls. Gutter joints, fascia trims and the movement joints in newer brickwork all need sealant that can flex.
We stand behind the work with a 12-month guarantee.
- Where
- Amersham (HP6, HP7)
- Wider area
- Buckinghamshire
- Guarantee
- One year on every job
- Price
- A clear price before work begins
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
Keeping the joints in good condition
Good habits help new joints last longer. A few tips:
- Keep water from gutters off the wall
- Check the sealant is paintable before painting near it
- Keep high-pressure jets off the joints
- Make sure movement joints are not pointed over
Only paint over the joint if we’ve confirmed the sealant can take paint. Paint can crack on a flexible joint.
Small splits are the time to act. At that stage it’s a simple cut out and reseal.
Walls and rooflines in Amersham
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 Chenies Manor House (about 3 miles east) nearby, there’s older building stock in the area around Amersham as well as newer homes. In older buildings, older brick and stone need a sealant that suits them, at the right joint depth.
Letting a property close to Amersham station? Then split movement joints are easy to miss on a rental until damp shows inside.
Amersham is about 7 miles north-east of High Wycombe, in Buckinghamshire. We carry out external mastic for homes and businesses in Amersham and nearby, as part of our work across Buckinghamshire. 263 places in Buckinghamshire are on our list, from the larger towns to small villages. Reading is on our list too, around 23 miles away.
Here we cover the HP6 and HP7 postcode area for external mastic. External mastic is available to properties on Station Road, London Road West and Market Square and the roads around them. Main roads around Amersham include the A355 and A404, so getting to you is simple. Neighbouring places we cover for external mastic include Amersham on the Hill (1 mile west), Chesham Bois (1 mile north), Waterside (1 mile north), Coleshill (2 miles south-west) and Hyde Heath (2 miles north-west). Larger places within reach include Aylesbury (13 miles north-west), High Wycombe (7 miles south-west), Chesham (3 miles north), Marlow (10 miles south-west), Beaconsfield (5 miles south-west) and Chalfont St Peter (5 miles south). Being one of Buckinghamshire’s larger places, Amersham has homes, rented property and businesses of every kind.
Around Amersham
Around Amersham, our work takes us to homes and buildings near The Pheasant Public House, Woodside Junior School and Dr Challoner's Grammar School. Amersham has its own railway station: Amersham station. Nearby you’ll also find Amersham Hospital (1.2 miles south-west) and Amersham Fair Organ Museum (less than half a mile north-east). Open spaces near Amersham include Sands Bank.
Your questions about external mastic in Amersham
I let a flat near Amersham station. Can you help?
Yes, rental work is part of what we do. Just phone 0345 464 0079 or drop us an email and tell us about the property, and we will give you a clear quote.
Can you do external mastic in Amersham?
Yes. Our work covers London and the South East, and Amersham is part of that. You can phone 0345 464 0079 or drop us an email and tell us what needs doing, and we’ll send you a clear quote.
Do you guarantee your work?
Yes. There’s a 12-month guarantee on every job, large or small.
Are you fully insured?
Yes. We’re fully insured.
When is the sealant fully cured?
Different products cure at different speeds, so please follow the time we give you.
What do you need from me for a quote?
A short description and the location, plus photos if you have them. We will ask anything else we need to know.
Do you remove the old sealant?
Yes. Sealing over the old bead is the commonest cause of early failure, so we never do it.
Will it make a mess?
No. We protect the surfaces around the joints, and we clear up the old sealant and our materials before we leave.
DIY versus a professional finish
What a professional job adds is preparation and the right product. We take joints back to clean, dry surfaces, and the sealant is matched to the joint and its conditions.
Some jobs are best left to a professional: high-level joints, fire-rated gaps, external movement joints and big jobs need the right product, the right access and the right method.
Towns and villages near Amersham
Other services in Amersham
What happens if it’s left?
A failed movement joint lets water into the wall and can run behind render or cladding. Dealing with it early keeps the repair to the joint, rather than the wall around it. In a family home in Amersham, a failed seal around a bath or a frame lets water into places you cannot see, like the floor under a bath, the back of a panel or the inside of a wall. Whatever the joint, failed sealant only gets worse.
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, and we will explain the quote if you ask.
Why Amersham clients choose us
- White, clear, grey or another colour, product permitting
- Over 20 years’ experience
- ARBOMaster approved applicator
- 4.9 on Google from 180+ five-star reviews
Read our cost guide or what customers say.
Common problems we fix in Amersham
If plants are growing out of a joint, the sealant has normally failed or was never there. Dirt and roots then trap moisture in the joint and speed up the damage.
If you can see any of these, it’s time to have the joints looked at:
- Water getting into walls through failed joints
- Weathered mastic that no longer stretches
- Weeds or debris growing in open joints
- Movement joints with cracked, split or missing sealant
If you live in an older home near St. Michael and All Angels, an extension built onto an older house moves differently, and the joint between them takes the strain.
What your quote should include
- What insurance they hold
- How the joint is cleaned and prepared
- What happens if they find a problem under the old sealant
- Is VAT in the price?
What affects the quote in Amersham
For a quick quote, just ask. The main things that affect it are:
- Whether the work is at height
- Whether there’s mould to deal with
- Any working-time requirements on site
- How many areas need sealing
Combining jobs into one visit is normally more efficient than separate visits. We will give you a clear quote for the lot.
Helping us quote
To make quoting easier, let us know:
- What the problem is, such as mould, gaps, leaks or cracking
- Where the job is, and your postcode
- A few photos by email, if you can
- The type of property
For a quote, ring 0345 464 0079 or send us an email with the location and a short description of the problem. You’ll have a clear quote before we start.
Work for landlords, hotels and businesses
Failed sealant is one of the commonest items on a check-out report, and it’s easy to sort out between tenants. Several properties can be quoted together.
Whether it’s one flat or a portfolio, you get the same standard of work: old sealant fully removed, joints prepared properly and a one-year guarantee.
How it works
Before we leave, we go over the finished joints with you and explain the cure time. The work normally takes a few hours to a few days, depending on the length of joint and the access, depending on the size of the job. For a job in Amersham, we need access to where the work is and somewhere nearby to park. If the job is outside, mention gates, side access and anything above ground floor.
- First, the joints are inspected and the access agreed.
- Every bit of old sealant and any mortar or debris is cut out.
- Joint faces are cleaned back and primed if the sealant needs it.
- Backing rod sized to the joint goes in to set the depth.
- We apply the sealant, tool it and check the whole run.
Preparing for the visit
- Plan for the work area to be out of bounds to pets and children
- Mention any tricky access
- For business premises, tell us about site rules or sign-in
Getting a quote
Want a quote for external mastic? Please ring 0345 464 0079 or email us and tell us about the job. We’ll explain what we’d do and give you a clear quote before any work starts.