Buckinghamshire · England
Chearsley External Mastic
External mastic for Chearsley, by sealant specialists with 20+ years’ experience. 180+ five-star Google reviews and a 4.9 rating.
- Weathered mastic that no longer stretches
- Movement joints with cracked, split or missing sealant
- Plants rooting in failed movement joints
External mastic in Chearsley, done properly
We cut out failed sealant, set the joint depth with closed-cell backing rod and reseal with a low-modulus exterior sealant. The colour is chosen to suit the brick or render so the line blends in. We work on façade panels, render & cladding joints and copings & trims, and the jobs we see most are failed seals between different materials and failed sealant between panels on a façade.
Around Chearsley, older buildings can be stone, brick or timber-framed, many with extensions added later. The joints where those materials meet are the weak points, and they need the right sealant at the right depth.
Big or small, you get the same 12-month guarantee.
- Place
- Chearsley (HP18)
- Wider area
- Buckinghamshire
- Cover
- A year, on every job
- Quotes
- A clear price before we start
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
Landlord and commercial work in Chearsley
Water getting past a failed joint can damage the building, which matters even more when someone else lives there. Keeping joints in good order is simple maintenance that we can handle for you.
We also work for businesses, from offices to washrooms and kitchens. On commercial sites, working times can be discussed when we quote.
Also near Chearsley
Other services in Chearsley
Surface by surface
Joints between dissimilar materials
Brick against render, concrete against metal, stone against timber: every change of material is a joint. We seal the joint with a flexible exterior sealant so neither cracks the other.
Copings and trims
Metal and stone copings both move with temperature, so a flexible sealant suits them best in all weathers.
Why it’s worth doing now in Chearsley
It often makes sense to reseal all the failing joints on an elevation together. Joints of the same age tend to fail together, and access only has to be arranged once. Around Chearsley, older homes often have timber in their floors and frames, where water from a failed joint can cause rot if it’s left.
What it costs depends on how much there is to do, how hard the old material is to remove and how easy the joints are to reach. You’ll have a clear quote before any work starts.
Why Chearsley customers choose us
- Experience in homes, commercial sites and hotels
- We are fully insured
- We never seal over old sealant
- 180+ five-star Google reviews
Take a look at what affects the cost or customer reviews.
The process
On the day, we look over the joints with you first. Surfaces next to the work are protected before any work begins. Most jobs take a few hours for a handful of joints, longer for a whole elevation. Somewhere like Chearsley needs a little journey planning: let us know about lanes, gates and parking. Everything for the job comes with us, so a second trip is avoided where possible.
- We start by checking each joint, agreeing the ones to redo and how we’ll reach them.
- We cut out the failed sealant and rake out any dirt or growth.
- We clean both faces of the joint and prime them where the product calls for it.
- Closed-cell backing rod is fitted to set the depth and stop three-sided bonding.
- We gun in a flexible exterior sealant in a colour that suits the wall and tool it neatly.
How to prepare
- Plan for the work area to be out of bounds to pets and children
- Mention any leaks or damp you’ve noticed
- Try not to wet indoor joints just before the visit
Get a quote
Want a quote for external mastic? Please call 0345 464 0079 or drop us an email with a few details. You’ll know what we plan to do, and what it will cost, before any work begins.
Related advice
Should I try it myself first?
Not every job suits DIY: work at height, external movement joints, fire-rated sealant and large areas need the right product, the right access and the right method.
If you’ve already had a go yourself, that’s fine. We remove it and do the joint properly, so just mention it when you contact us.
Keeping the joints in good condition
Once the sealant has cured, a few habits help it last:
- Don’t let climbing plants root in the sealant
- Ask before painting over external sealant
- Tell anyone working on the walls about the movement joints
- Make sure movement joints aren’t pointed over
Follow the cure time we give you before the joint is knocked or disturbed. Most exterior sealants skin fast but take longer to cure right through.
Water getting behind cladding or render can go unnoticed for a long time. By the time there’s a damp patch, the damage can be well established so early resealing is worth it.
Questions from Chearsley
I let a flat near Haddenham & Thame Parkway 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 send you a clear quote.
Do you cover smaller places like Chearsley?
Yes, Chearsley is covered. We work across London and the South East, from towns to the smallest places. Longer journeys are simply planned in advance.
What is backing rod for?
Backing rod goes into deeper joints as a matter of course. It controls the depth and stops the sealant bonding to the back, so the joint can move.
What is a movement joint?
Brickwork, render and cladding all move a little, and planned joints take up that movement. It’s closed with backing rod and a flexible sealant.
Do you take out the old sealant first?
Yes, always, and completely. New sealant will not bond properly to old, so the joint is cleaned back first.
Can a movement joint be filled with mortar?
No, not if it’s a movement joint. Pointing it stops it working. A flexible sealant is the right fill.
Do the sealants smell?
Possibly a little. Any smell clears as the sealant cures.
Is it messy?
Not at all. The area is protected while we work and cleaned up afterwards.
What we can’t put right
In fairness, there are a few things sealant will not fix:
- Damp from another source, such as a leaking gutter or a bridged damp-proof course
- Cracks in the bricks or render themselves, away from the joints
- Loose or hollow render, which needs re-rendering
If you are not sure, just ring 0345 464 0079 or drop us an email and we will give you a straight answer.
Joints and surfaces we work on
- Render & cladding joints
- Joints between brick and frames
- Façade panels
- Copings & trims
- Concrete & block
- Brickwork movement joints
Chearsley buildings and the weather
Historic houses like Waddesdon Manor (about 3.7 miles north) are a reminder that the area around Chearsley has older buildings as well as new. In older buildings, 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.
Homes close to Parish Church of St Nicholas include some older properties, and older walls, gutters and the joints where extensions meet them need a flexible sealant. Rented homes near Haddenham & Thame Parkway station change hands often, and split movement joints are easy to miss on a rental until damp shows inside.
Chearsley is about 3 miles north of Thame, in Buckinghamshire. Anywhere in HP18, we cover external mastic for homes and businesses. Across Buckinghamshire, we cover 263 places, and Chearsley is one of them. We also work in Oxford, about 12 miles from Chearsley.
Jobs for external mastic in HP18 is quoted and booked the same way as anywhere else. That includes homes and businesses on School Lane, Bernard's Close and Aylesbury Road. We also cover the places around Chearsley: Cuddington (1 mile east), Long Crendon (2 miles south-west), Haddenham (2 miles south-east), Gibraltar (2 miles east) and Kingsey (3 miles south-east). Further out, we also cover Aylesbury (6 miles east), High Wycombe (14 miles south-east), Buckingham (14 miles north), Elmhurst (7 miles east), Southcourt (6 miles east) and Princes Risborough (7 miles south-east).
Landmarks near Chearsley
For rail, the closest station is Haddenham & Thame Parkway station, roughly 1.5 miles south-east. Other landmarks nearby include Thame Museum (3 miles south) and Dinton Castle (3 miles east). The countryside around Chearsley includes Snakemoor.