Oxfordshire · England
External Mastic in Kencot
Sealing brickwork movement joints, render, cladding and façade joints for Kencot, backed by a one-year guarantee. Call for a quick quote.
- Movement joints with cracked, split or missing sealant
- Panel joints letting water in
- Cracked joints where brick meets render or frames
About our external mastic in Kencot
We cut out failed sealant, set the joint depth with closed-cell backing rod and reseal with a low-modulus exterior sealant. We pick a colour that sits well with the wall so the line blends in. We work on façade panels, joints between brick and frames and concrete & block, and common reasons people get in touch are joints pointed up with cement by mistake and moss and dirt in joints with no sealant left.
Outside joints can only be sealed when they’re dry, so work in Kencot is booked around the forecast. Tell us about access to all sides of the building, including outbuildings and garages.
We guarantee the work for a year. If there’s a problem with our work within the year, let us know and we’ll sort it.
- Location
- Kencot (OX18)
- Region
- Oxfordshire
- Cover
- One year on every job
- Price
- A clear quote up front
- Call
- 0345 464 0079
- Updated
- 26 October 2026
Walls and rooflines in Kencot
With historic houses such as Kelmscott Manor (about 4 miles south) nearby, there’s older building stock in the area around Kencot 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, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
For an older house near a landmark such as Church of St Peter, older walls, gutters and the joints where extensions meet them need a flexible sealant.
Kencot is about 2 miles south-west of Carterton, in Oxfordshire. Anywhere in OX18, our applicators can take on external mastic. Kencot is one of 443 towns and villages in Oxfordshire where we work. For nearby work, see our Oxford page, about 16 miles away.
Work in OX18 works the same way as everywhere else we cover. Close by, we work in Alvescot (1 mile south-east), Shilton (2 miles north) and Bradwell (3 miles north-west). Within a short drive, we also cover Abingdon-on-Thames (15 miles east), Witney (6 miles north-east), Wantage (13 miles south-east), Grove (12 miles south-east), Faringdon (6 miles south) and Kidlington (15 miles east).
Around Kencot
Locally, jobs take us to homes and businesses close to The Plough pub and Carterton Community College and the streets around them. A little further out are Swinford Museum (1.9 miles west) and Longworth Hospital (5.9 miles south).
Other services in Kencot
For landlords and businesses
Businesses can book us for washrooms, kitchens, offices and more. On commercial sites, working times can be discussed when we quote.
For anyone letting property in or around Kencot, jobs at different addresses can go on one quote. Just tell us the addresses and what each one needs, and photos by email help.
What we can’t put right
Sealant isn’t the answer to every problem, and we’d rather say so up front. Sealant will not put right:
- Adding movement joints to masonry that has none
- Movement that is more than a sealant joint can take
- Rising or penetrating damp from elsewhere in the wall
If you’re not sure, just call 0345 464 0079 or drop us an email and we will give you a straight answer before booking.
Surfaces we seal
- Brickwork movement joints
- Copings & trims
- Façade panels
- Render & cladding joints
- Joints between brick and frames
- Concrete & block
What affects the cost of external mastic
Jobs vary more than people expect. What affects the quote:
- Which sealant suits the joint
- Any working-time requirements on site
- Mould in or behind the old joints
- The number of rooms or windows
The cost depends on the size of the job, how much old material has to come out and access to the work. We give a clear quote before any work starts, so you know where you stand.
Asking for a quote
Before you ask for a quote, have a think about:
- Whether it has been sealed before
- What’s wrong with the joints now
- Where the job is, and your postcode
- Access, such as stairs, a lift or height
A good description makes for an accurate quote. Tell us where the job is, what’s wrong and how much there is, and email photos if that’s easy.
Looking after it afterwards
To keep the joints looking good and working properly:
- Leave the joints unpainted unless we have said otherwise
- Deal with leaking gutters that soak the joints below
- Get split or bare joints resealed while the damage is small
- Keep soil, plants and ivy away from the joints
Have a quick look at the joints each spring. Splits, gaps at the edges or plants in the joint are early warning signs.
Act while the splits are small. At that stage it’s a simple cut out and reseal.
FAQs for Kencot
Do you cover smaller places like Kencot?
Yes, smaller places are covered as well as towns. Our work covers London and the South East. Let us know about access, parking and anything unusual about getting there when you book.
Is external mastic in Kencot guaranteed?
Every job comes with our one-year guarantee, wherever it is. We are fully insured, and an ARBOMaster approved applicator.
Can new sealant go over the old?
No. Fresh sealant doesn’t stick to old sealant, and anything trapped underneath, including mould and water, stays there. It all has to come out first.
Can you seal joints between two different materials?
Yes. Materials like render, brick, metal and uPVC all move differently, so a flexible sealant is needed where they meet. We choose one that suits both surfaces.
Is it worth trying it myself?
Some simple jobs can be done by a careful DIYer. The usual mistakes are sealing over old sealant, sealing a damp joint and using too much.
Is it OK to fill a movement joint with cement?
No. Rigid materials cannot move with the wall, so the joint stops doing its job. Where a joint has been mortared, it can often be raked out and sealed properly.
Do you use backing rod?
That is backing rod, a closed-cell foam. It stops the sealant going in too deep and bonding to three sides so it can flex with the joint.
Will the old sealant be removed?
Yes. Sealing over the old bead is the commonest cause of early failure, and it’s something we never do.
Signs you need external mastic in Kencot
Sometimes a movement joint was filled with mortar or a rigid filler, often by someone who didn’t know what it was for. With the joint locked solid, the movement turns into cracks elsewhere in the wall.
Look out for these signs:
- Weeds or debris growing in open joints
- Failed seals between different materials
- Old sealant gone brittle and cracked
- Failed sealant between panels on a façade
Managing a site like St Peter's Church of England School? Then its movement joints, gutters and trims need looking after like any other building’s.
Before you book anyone
- Whether you can choose the colour
- Whether they seal over old material or remove it
- What preparation is included
- Whether they’re fully insured
What happens on the day
Once we are on site, we check the joints match what you told us. If anything is different, we explain it before carrying on. Most jobs then take a few hours for a handful of joints, longer for a whole elevation. Somewhere like Kencot 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 inspect the joints and agree which need resealing and how they’ll be reached.
- Old sealant and any debris are cut and raked out.
- Both sides are cleaned back to sound material and primed if needed.
- Closed-cell backing rod is fitted to set the depth and stop three-sided bonding.
- The new sealant, chosen to suit the brick or render, is applied and tooled to a neat finish.
Preparing for the visit
- Plan for the work area to be out of bounds to pets and children
- Tell us about access, such as stairs, a lift or high-level joints
- Where the joints are inside, avoid wetting them before we arrive
How to get a quote
There’s no standard price list, as no two jobs are quite the same. Instead, we send you a clear quote for your job. To get started, phone 0345 464 0079 or email us.
Advice
Different surfaces, different methods
Concrete and blockwork
Wide joints in concrete need the depth controlling carefully. We size the backing rod to the gap so the sealant is not too deep.
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.