Oxfordshire · England
External & façade joints in Merton, Oxfordshire
Sealing brickwork movement joints, render, cladding and façade joints for householders, landlords and businesses in Merton. ARBOMaster approved applicators, fully insured, with a one-year guarantee.
- Moss and dirt in joints with no sealant left
- Water getting into walls through failed joints
- Sealant that has lost its bond to the brick or render
About our external mastic in Merton
For buildings in Merton, we reseal external joints of all kinds, from brick movement joints to cladding panels. Every joint gets the same careful preparation: clean joint faces and the right depth. We work on render & cladding joints, joints between brick and frames and brickwork movement joints, and common reasons people get in touch are joints pointed up with cement by mistake and sealant pulling away from one side of the joint.
Outside joints can only be sealed when they’re dry, so work in Merton is booked around the forecast. Tell us about access to all sides of the building, including outbuildings and garages.
A 12-month guarantee comes with the work, just as it does everywhere we cover.
- Location
- Merton (OX25)
- Wider area
- Oxfordshire
- Cover
- One year on every job
- Price
- A clear quote up front
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
Keeping the joints in good condition
Once the sealant has cured, a few habits help it last:
- Point out the joints to other trades
- Have failed joints looked at early
- Ask before painting over external sealant
- Make sure movement joints are not pointed over
Keep the joints clear of soil, plants and climbing growth. Damp material against the sealant shortens its life.
Act while the splits are small. Then it’s a straightforward cut-out and reseal with no damage behind it to deal with.
Places near Merton
What else we do in Merton
Common questions in Merton
Is Merton within the area you cover?
Yes, smaller places are covered as well as towns. We work across London and the South East. Let us know about access, parking and anything unusual about getting there when you book.
Is Merton in your area for external mastic?
Yes, Merton is within the area we cover. We work across London and the South East. Just call 0345 464 0079 or email us with a few details of the job, and we will give you a clear price.
Are you fully insured?
Yes. We’re fully insured.
How long does the job take?
Most jobs take anything from a few hours to several days, depending on the building. Your quote will say how long we expect yours to take.
Can tenants book the work?
Yes, though it’s best to check with your landlord first. Many landlords are glad to have it sorted.
Can you work on commercial sites?
Yes. Larger jobs can be planned room by room or area by area.
Is it worth trying it myself?
You can, for simple jobs. The key is preparation: remove all the old material and work on a clean, dry joint. We can always put it right if it fails.
Do I need to be at home?
Access is agreed with you when the job is booked. For inside work, that normally means someone being in.
External mastic in Merton: local notes
With historic houses such as Boarstall Tower (about 3.7 miles south-east) nearby, there’s older building stock in the area around Merton as well as newer homes. In older buildings, older walls and rooflines need a sealant that moves with them and suits the material. 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.
In the older streets around Church of St Swithin, an extension built onto an older house moves differently, and the joint between them takes the strain.
Merton is about 3 miles south of Bicester, in Oxfordshire. Every kind of property in Merton can book us for external mastic. Every job comes with our 12-month guarantee. Across Oxfordshire, we cover 443 places, Merton among them. Our Oxford page covers work nearby, about 8 miles away.
Postcode districts we cover here for external mastic: OX25. Other places close to Merton include Fencott (1 mile south), Murcott (1 mile south-east), Charlton-on-Otmoor (1 mile south-west), Wendlebury (2 miles north-west) and Lower Arncott (2 miles east). Further out, we also cover Oxford (8 miles south), Bicester (3 miles north), Abingdon-on-Thames (13 miles south), Witney (15 miles west), Thame (11 miles south-east) and Kidlington (6 miles south-west).
Near you in Merton
Around Merton, our work takes us to homes and buildings near The Old Plough pub and the streets around them. The closest station to Merton is Bicester Village station, about 2.7 miles north of the centre. Well-known places in the area include Bicester Community Hospital (2.9 miles north) and Bicester Avenue (2.3 miles north). For a walk, there’s Graven Hill and Woodsides Meadow.
Should I try it myself first?
The difference is mostly in the preparation and the product. Joints are cleaned back to sound surfaces and dried, and the sealant is chosen for how the joint moves and where it is.
Overfilling a joint is a classic DIY mistake. A thick, smeared bead looks untidy and does not move well, and getting the depth right matters as much as the look.
What happens on the day
There is not much for you to do on the day. Point us to the joints and we will get on with it. The work itself takes a few hours to a few days, depending on the length of joint and the access, including the tidy-up. For a village or hamlet like Merton, the journey is planned in advance: let us know about lanes, gates and parking. We bring what the job needs, so it can be finished in one trip 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.
- The joint faces are cleaned and primed where the sealant needs 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.
Getting ready for the visit
- For business premises, tell us about site rules or sign-in
- Plan for the work area to be out of bounds to pets and children
- Tell us about any previous sealing or DIY attempts
Getting a quote
To get a quote, phone 0345 464 0079 or drop us an email with the location and a short description of the problem. You’ll have a clear quote before we start.
Advice
Do you need external mastic in Merton?
Every building moves. Clay bricks expand slightly over their life, concrete and block shrink, and everything moves with temperature and wet. The sealant in the movement joints takes that strain.
These are the problems we are asked about most:
- Moss and dirt in joints with no sealant left
- Brick movement joints where the sealant has split
- Weathered mastic that no longer stretches
- Failed sealant between panels on a façade
For landlords with property near Bicester Village station, failed wall and movement joints let damp in, so they’re worth checking between tenancies.
Before you book anyone
- How the surfaces are prepared before sealing
- Who does the work, and how experienced they are
- What the cure time is
- Are they insured?
Why deal with it now?
Water gets in through a failed movement joint and can run behind render or cladding. Dealing with it early keeps the repair to the joint, rather than the wall around it. Older cottages and farmhouses around Merton can have timber floors and frames, where water from a failed joint can cause rot if it’s left.
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 email us and we’ll give you an honest view and a quote.
Why book with us
- Every job guaranteed for a year
- Quality sealants from Arbo and Everbuild
- We never seal over old sealant
- 20+ years of sealant experience
Take a look at our cost guide and customer reviews.
How we quote for external mastic
We quote each job individually. These are the things that affect it:
- The type of sealant required
- The number of rooms or windows
- Working hours on commercial sites
- Access and height
The cost reflects the work involved, not guesswork. That’s why we ask a few questions first and agree the price before starting.
What to tell us for a quote
What to tell us when you ask for a quote:
- Roughly how big the job is
- The type of property
- The problem you’ve noticed
- Access, such as stairs, a lift or height
The more we know about the job, the more useful the quote. Tell us where the job is, what’s wrong and how much there is, and add pictures by email if you can.
Different surfaces, different methods
Concrete and blockwork
Wide joints in concrete need the depth controlling carefully. We size the backing rod to the gap and keep the sealant to the right depth.
Render joints
Rendered walls have joints at beads, openings and changes of material. They’re resealed in a sealant that suits the render.