Buckinghamshire · England
External Mastic in Lye Green
External mastic in Lye Green from a team with over 20 years’ experience. Rated 4.9 on Google from 180+ five-star reviews.
- Rigid filler in a joint that should flex
- Old sealant gone brittle and cracked
- Sealant that has lost its bond to the brick or render
Surface by surface
Brickwork movement joints
Brick moves with heat and moisture, and grows a little over time. The movement joint takes that up, so the sealant in it must stay soft and stretchy.
Joints between dissimilar materials
Joints where frames, sills or panels meet the wall are common leak points. The old joint is removed and a sealant that bonds to both sides goes in.
External mastic in Lye Green, done properly
A movement joint is a deliberate break that lets a wall expand and contract. 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. We’re often asked to deal with sealant that has lost its bond to the brick or render and weathered mastic that no longer stretches, on render & cladding joints, façade panels and joints between brick and frames.
Somewhere as small as Lye Green, homes and farm buildings often face open ground, so walls and rooflines take the full force of wind and rain. Joints on those walls need a sealant that moves with the building and stays in place.
Whatever the size of the job, it’s backed by our one-year guarantee in Lye Green and across Buckinghamshire.
- Place
- Lye Green (HP5)
- Wider area
- Buckinghamshire
- Guarantee
- 12 months on all our work
- Price
- A clear quote up front
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
Looking after it afterwards
After the cure time, these simple habits help:
- Wash walls gently around the sealant
- Point out the joints to other trades
- Keep water from gutters off the wall
- Keep soil, plants and ivy away from the joints
Look over the joints once a year, ideally after winter. Splits, gaps at the edges or plants in the joint are early warning signs.
Leaks behind façade panels and render often go unseen. By the time there’s a damp patch, the damage can be well established, so it’s worth resealing at the first signs.
What happens if it’s left?
Done well, a resealed joint is a neat, straight line that suits the wall. A rushed bead with no backing looks untidy and doesn’t last so it’s worth doing right. Older cottages and farmhouses around Lye Green can have timber floors and frames, and water through a failed joint can rot timber if it’s left.
Instead of a standard rate, we look at what your job involves: the amount of work, the old material and the access. The price is agreed before we begin.
Why choose Mr Mastic in Lye Green
- More than 20 years in sealant work
- Colour agreed with you before any work starts
- Homes, businesses and hotels
- Anti-fungal sanitary silicone in wet areas
How it works
Once we are on site, we check the joints match what you told us. If we find something unexpected, we talk it through with you first. Most jobs then take a few hours to a few days, depending on the length of joint and the access. Somewhere as small as Lye Green, access is often the only tricky part. If the job is outside, mention outbuildings, exposed walls and how to reach them.
- We start by walking round the building and agreeing the joints and the access.
- 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.
- Backing rod sized to the joint goes in to set the depth.
- We apply the sealant, tool it and check the whole run.
Getting ready for the visit
- Keep pets and children clear of the area while we work
- Clear the area around the work
- Mention any sign-in or site rules at work premises
How to get a quote
Asking for a quote is easy: let us know the job and the location. A few pictures by email make the job easier to understand, and we will come back to you with a quote.
Read more
DIY versus a professional finish
A careful DIYer can reseal a simple joint, like a short, easy-to-reach joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
Some jobs are best left to a professional: high-level joints, fire-rated gaps, external movement joints and big jobs call for the right materials, safe access and experience.
What we cannot put right
Sealant isn’t the answer to every problem, and we’d rather say so up front. It won’t solve:
- Movement that is more than a sealant joint can take
- Cracks in the bricks or render themselves, away from the joints
- Cutting new joints into brickwork, which is building work rather than sealant work
Not sure which it is? You can phone 0345 464 0079 or drop us an email and we will tell you honestly.
What we seal
- Render & cladding joints
- Concrete & block
- Joints between brick and frames
- Façade panels
- Copings & trims
- Brickwork movement joints
Lye Green questions
Can you help a landlord with a rental near Berkhamsted station?
Yes, we work for letting agents and landlords. Just ring 0345 464 0079 or email us and tell us about the property, and we will give you a clear quote.
Is Lye Green in your area for external mastic?
Yes, Lye Green is within the area we cover. Our work covers London and the South East. Just phone 0345 464 0079 or send us an email with a few details of the job, and we will give you a clear quote.
Do you use backing rod?
Backing rod goes into deeper joints as a matter of course. It sets the sealant depth and prevents three-sided bonding, so the joint can move.
Do I need to be at home?
We need access to the joints, so we will agree that with you when we book. Indoors, that generally means someone at home.
Do you hold any approvals?
Yes. ARBOMaster is the approved applicator scheme for Arbo sealants, and we’re part of it.
How long does external mastic last?
It varies with how exposed the wall is and how much the joint moves. Look for splits, hardening or edges coming away, and reseal at that point.
Where is Mr Mastic based?
We work from Crawley. We cover Lye Green and the rest of Buckinghamshire, along with the rest of our area.
What colours does the sealant come in?
There’s a good range of exterior colours, including greys, browns, whites and stone tones. We pick the one that suits your wall best so it doesn’t stand out.
External mastic in Lye Green: local notes
With historic houses such as Chenies Manor House (about 3.8 miles south-east) nearby, there’s older building stock in the area around Lye Green as well as newer homes. Where a home is older, older brick and stone need a sealant that suits them, at the right joint depth. Compared with the north and west, the South East gets less rain, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
Schools such as Brushwood Junior School are buildings too, and larger buildings have long runs of movement joint that eventually need resealing. Homes close to St George's Church include some older properties, and older walls, gutters and the joints where extensions meet them need a flexible sealant.
Lye Green is about 1 mile north-east of Chesham, in Buckinghamshire. For external mastic in and around Lye Green, it’s easy to get a quote: please call 0345 464 0079 or drop us an email. We cover Buckinghamshire from our Crawley base, Lye Green included. Our Buckinghamshire coverage runs to 263 places, Lye Green among them. Reading is on our list too, around 25 miles away.
We work across the HP5 postcode area for external mastic. External mastic is available to properties on Rushmere Lane, Two Dells Lane and Lycrome Road and the roads around them. If you’re just outside Lye Green, we cover Orchard Leigh (1 mile east), Botley (1 mile south), Tyler's Hill (1 mile south), Ley Hill (1 mile south-east) and Ashley Green (1 mile north). Within a short drive, we also cover Aylesbury (12 miles north-west), High Wycombe (10 miles south-west), Marlow (13 miles south-west), Amersham (3 miles south), Beaconsfield (8 miles south) and Chalfont St Peter (8 miles south).
What’s near Lye Green
In Lye Green, that means homes and buildings near Chesham Grammar School and The Hen And Chickens Public House, among other places. Lye Green’s nearest station is Berkhamsted station, roughly 3.1 miles north. A little further out are Hawridge Court (2.5 miles north-west) and Amersham Hospital (4.3 miles south-west). Not far away are Sands Bank.
Nearby places to Lye Green
What else we do in Lye Green
Signs you need external mastic in Lye Green
If plants are growing out of a joint, the sealant has normally failed or was never there. Roots and dirt hold water against the wall and make things worse.
Keep an eye out for these signs:
- Failed seals between different materials
- Old sealant gone brittle and cracked
- Movement joints with cracked, split or missing sealant
- Failed sealant between panels on a façade
Letting a property close to Berkhamsted station? Then outside joints that have cracked can let damp into a rental, so check them between lets.
What your quote should include
- Which colour the sealant will be
- How long the guarantee is
- Whether they seal over old material or remove it
- How hidden problems are handled