Oxfordshire · England
External & façade joints in Kennington, Oxfordshire
Sealing brickwork movement joints, render, cladding and façade joints for householders, landlords and businesses in Kennington. Fully insured, ARBOMaster approved and guaranteed for a year.
- Joints where the bead has come unstuck
- Movement joints filled with mortar instead of sealant
- Plants rooting in failed movement joints
What we can’t put right
Some problems need a builder, plumber or other trade rather than us:
- Cracks in the bricks or render themselves, away from the joints
- Subsidence or other structural problems
- 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 send us an email and we’ll tell you honestly.
What we seal
- Brickwork movement joints
- Concrete & block
- Render & cladding joints
- Copings & trims
- Joints between brick and frames
- Façade panels
External mastic in Kennington, done properly
Failed sealant is cut out, the depth set with closed-cell backing rod, and the joint resealed with a low-modulus sealant made for outside. The colour is chosen to suit the brick or render so the line blends in. We’re often asked to deal with brick movement joints where the sealant has split and failed seals between different materials, across concrete & block, brickwork movement joints and copings & trims.
Homes around Kennington range from older cottages to newer houses, with walls and rooflines of every type. Older gutters and trims need their joints resealed; newer brick and render need their movement joints kept sound.
All our work comes with a 12-month guarantee.
- Where
- Kennington (OX1, OX14)
- Wider area
- Oxfordshire
- Cover
- 12 months on all our work
- Quotes
- A clear quote up front
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
Looking after it afterwards
So the new joints stay in good condition:
- Keep movement joints as flexible joints, not mortar
- Tell anyone working on the walls about the movement joints
- Act on the first splits you see
- Fix overflowing gutters above sealed joints
Keep pressure washers away from the sealant. A strong jet can damage the edges of the bead over time.
Leaks behind façade panels and render often go unseen. By the time there’s a damp patch, the damage can be well established.
Nearby places to Kennington
More services for Kennington
What affects the cost of external mastic
There’s no set price list, because jobs vary so much. What we look at:
- How easy the joints are to reach
- Whether there’s mould to deal with
- The number and length of the joints
- When we can work, for business premises
A failed joint rarely gets cheaper to fix by waiting, as water and mould keep getting in. If you are unsure, call 0345 464 0079 or drop us an email and we’ll give you an honest view and a quote.
Helping us quote
When you contact us, it’s useful to know:
- Roughly how big the job is
- Any previous sealing or DIY work
- How we’d reach the joints
- The address or postcode of the job
Want a quote for external mastic? Please call 0345 464 0079 or send us an email and tell us about the job. You will know what we plan to do, and what it will cost, before any work begins.
Your questions about external mastic in Kennington
Will you come out to Kennington?
Yes. Kennington is within the area we cover, which takes in towns, villages and rural addresses. We work across London and the South East. Just mention lanes, gates or anything else about the route when you book.
Is Kennington in your area for external mastic?
Yes. Our work covers London and the South East, and Kennington is part of that. Just ring 0345 464 0079 or send us an email with a few details of the job, and we’ll give you a clear price.
Can you seal over the old sealant?
No, it will not last. It can look neat for a few weeks, but the new bead soon lifts. The old sealant has to come out completely.
How long will you be here?
A typical job takes anything from a few hours to several days, depending on the building. We’ll confirm how long when we quote.
Do you guarantee your work?
Yes. All our work carries our one-year guarantee.
I’m a tenant. Can you help?
Of course. Check with your landlord; we can send the quote to them too.
Do you take out the old sealant first?
Yes, always, and completely. New sealant will not bond properly to old, so any old material comes out before anything new goes in.
Can you do several jobs on one visit?
Of course. Doing several areas at once is normally more efficient, so mention them when you ask for a quote.
What we are called out for in Kennington
Every building moves. Clay bricks expand slightly over their life, concrete and block shrink, and everything moves with temperature and wet. All of that ends up in the joint sealant.
Most people get in touch when they notice something like this:
- Panel joints letting water in
- Sealant pulling away from one side of the joint
- Moss and dirt in joints with no sealant left
- Brick movement joints where the sealant has split
For landlords with property near Radley station, outside joints that have cracked can let damp into a rental, so check them between lets.
Questions to ask before booking
- How long the guarantee is
- What product goes in the joint
- What insurance they hold
- Is the old sealant removed completely?
Work for landlords, hotels and businesses
Housing providers, facilities teams and property managers book us too in Kennington and across Oxfordshire. We can quote a run of properties together, and we are fully insured for the work.
A neglected joint can let water reach the structure, which matters even more when someone else lives there. Keeping joints in good order is simple maintenance.
What happens on the day
Our applicators work methodically: protection first, then preparation, sealing and a tidy-up. Typically it takes a few hours to a few days, depending on the length of joint and the access, and the area is left clean. For a job in Kennington, we agree the time, the access and parking before the day. If the work is outside, the weather plays a part, as sealant needs a dry surface.
- We start by checking each joint, agreeing the ones to redo and how we’ll reach them.
- The old mastic and anything lodged in the joint is removed.
- The joint faces are cleaned and primed where the sealant needs it.
- We push in closed-cell backing rod so the sealant is the right depth and bonds to the sides only.
- The new sealant, chosen to suit the brick or render, is applied and tooled to a neat finish.
How to prepare
- Tell us about any previous sealing or DIY attempts
- On commercial sites, let us know about site rules
- Plan for the work area to be out of bounds to pets and children
How to get a quote
We quote each job on its own, so start by telling us what you need. Just call 0345 464 0079 or send us an email with the details.
Read more
Why it’s worth doing now in Kennington
Sealing over the top of old mastic does not hold for long. New sealant doesn’t bond well to old, weathered sealant, so the old joint is cut out fully first. Around Kennington, water from a failed joint in an older home can soak into timber and plaster, which is far harder to put right than the sealant itself.
The cost depends on the size of the job, 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 choose Mr Mastic in Kennington
- Colour picked to suit the job
- Arbo and Everbuild products
- Approved under the ARBOMaster scheme
- 12-month guarantee on every job
Read our cost guide and what customers say.
What external mastic looks like in Kennington
London and the South East are among the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day. Historic houses like Holywell Manor (about 3.1 miles north) are a reminder that the area around Kennington 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.
Homes close to St Swithun's Church include some older properties, and older walls, gutters and the joints where extensions meet them need a flexible sealant. Managing a site like St Swithun's CofE Primary School? Then its movement joints, gutters and trims need looking after like any other building’s.
Kennington is about 3 miles south of Oxford, in Oxfordshire. Every kind of property in Kennington can book us for external mastic, old or new, large or small. Every job comes with our 12-month guarantee. Our Oxfordshire coverage runs to 443 places, Kennington among them.
We work across OX1 and OX14 for external mastic and the streets around it. External mastic is available to properties on Simpsons Way, The Avenue and Liddiard Close and the roads around them. If you’re just outside Kennington, we cover Sandford-on-Thames (1 mile east), Littlemore (1 mile north-east), Redbridge (1 mile north), Hinksey Hill (1 mile north-west) and Bayworth (1 mile west). Larger places within reach include Oxford (3 miles north), Didcot (7 miles south), Bicester (14 miles north), Abingdon-on-Thames (3 miles south-west), Witney (12 miles north-west) and Carterton (15 miles west).
Near you in Kennington
Locally, jobs take us to homes and businesses close to The Oxford Academy, Emmanuel Christian School and The Tandem pub. Kennington’s nearest station is Radley station, about 1.8 miles south. Well-known places in the area include Templars Square (1.9 miles north-east) and Oxford Castle and earlier settlement remains (2.9 miles north). Not far away are Lashford Lane Fen and Harcourt Hill.