Oxfordshire · England
External Mastic in Cassington
Sealing brickwork movement joints, render, cladding and façade joints for Cassington, backed by a one-year guarantee. Ask us for a quote.
- Sealant that has lost its bond to the brick or render
- Gaps where render, brick and frames meet
- Rigid filler in a joint that should flex
Can I do it myself?
Sealing over old silicone is the commonest DIY error. Silicone doesn’t stick to old silicone, so it lifts and traps water and mould underneath. All the old material has to come out first.
A careful DIYer can reseal a simple joint, like a short, easy-to-reach joint indoors. The common mistakes are sealing over old sealant, sealing a damp joint and using far too much.
External mastic for homes and businesses in Cassington
Getting the depth right is half the job. Closed-cell backing rod sets the depth and stops the sealant sticking to the back, leaving it bonded to two faces so it can move with the wall. We work on concrete & block, brickwork movement joints and copings & trims, and people most often call us about weathered mastic that no longer stretches and moss and dirt in joints with no sealant left.
Somewhere as small as Cassington, homes and farm buildings often face open ground, where walls and rooflines take the weather head on. Gutter joints and wall joints there need a sealant that can flex and stay put.
You’re covered for a year from the day we finish. If anything isn’t right with it, ring 0345 464 0079 or email us.
- Location
- Cassington (OX29)
- Region
- Oxfordshire
- Guarantee
- 12 months on all our work
- Quotes
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
Work for landlords, hotels and businesses
A neglected joint can let water reach the structure, which is a bigger problem in a rented property. Resealing at the right time is simple maintenance.
If you manage several properties in or around Cassington, several properties can be quoted together. Just tell us the addresses and what each one needs.
External mastic in Cassington: local notes
Historic houses like Blenheim Palace (about 3.4 miles north) are a reminder that the area around Cassington has older buildings as well as new. 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, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
For landlords with property near Hanborough station, failed wall and movement joints let damp in, so they’re worth checking between tenancies. Homes close to Church of St Peter include some older properties, and an extension built onto an older house moves differently, and the joint between them takes the strain. Schools such as St Peter's Church of England Primary School are buildings too, and movement joints, cladding joints and gutters on larger buildings need the same care as a house’s.
Cassington is about 6 miles north-west of Oxford, in Oxfordshire. Across the OX29 area, our applicators can take on external mastic. Cassington is one of 443 towns and villages in Oxfordshire where we work. We also work in Oxford, around 6 miles away.
Work in OX29 works the same way as everywhere else we cover. You’ll find streets such as Church Lane, The Green and Pound Lane, all of which we cover. We also cover Swinford (1 mile south-west), Eynsham (2 miles south-west), Wytham (2 miles south-east), Farmoor (2 miles south) and Filchampstead (3 miles south). We also work in nearby towns such as Oxford (6 miles south-east), Didcot (13 miles south), Bicester (11 miles north-east), Abingdon-on-Thames (8 miles south), Witney (6 miles west) and Carterton (11 miles west).
Near you in Cassington
Locally, jobs take us to homes and businesses close to Bartholomew School and Chequers Inn, among other places. The closest station to Cassington is Hanborough station, about 2.5 miles north-west. Nearby you’ll also find Oxford Castle and earlier settlement remains (4.5 miles south-east) and Radcliffe Infirmary (4.1 miles south-east). Green spaces nearby include Hook Meadow and The Trap Grounds and Cumnor Hill.
Nearby places to Cassington
More services for Cassington
How the job changes by surface
Render joints
Water behind render can lead to blown patches. Resealing the joints early keeps water out and protects the render itself.
Copings and trims
Copings expand and contract through the day, so a flexible sealant suits them best in all weathers.
What affects the quote in Cassington
There’s no set price list, because jobs vary so much. The quote depends on:
- The product the joint needs
- How easy the joints are to reach
- Whether old sealant or filler has to be cut out
- Any mould that needs treating
Some things make a job bigger or smaller: the old material and how easily it comes out, whether mould needs treating, and whether the work is at height. We take all of that into account in your quote.
Helping us quote
A few details help us give you an accurate quote. When you get in contact, it helps to mention:
- If it’s domestic, commercial or a hotel
- How many joints, rooms or windows are involved
- What’s wrong with the joints now
- Whether it has been sealed before
To get a quote, call 0345 464 0079 or send us an email with the location and a short description of the problem. You’ll have a clear quote before we start.
What we can’t put right
Sealant isn’t the answer to every problem, and we’d rather say so up front. It will not solve:
- Failed render or damaged cladding panels
- Damp that is not coming from the joint
- Cracks in the bricks or render themselves, away from the joints
Not sure which it is? You can ring 0345 464 0079 or email us and we will tell you honestly before booking.
Joints and surfaces we work on
- Render & cladding joints
- Brickwork movement joints
- Concrete & block
- Façade panels
- Joints between brick and frames
- Copings & trims
Looking after it afterwards
A little care helps the new joints last. Our advice:
- Leave the joints unpainted unless we’ve said otherwise
- Keep water from gutters off the wall
- Check external joints each spring
- Have failed joints looked at early
Look over the joints once a year, ideally after winter. Watch for splits, edges coming away or growth in the joint.
An open movement joint lets rain into the wall every time it pours. That can lead to damp patches, staining and frost damage, all bigger jobs than a reseal.
How it works
When we get to you, we compare the joints with what we discussed. If anything is different, we explain it before carrying on. Most jobs then take a few hours to a few days, depending on the length of joint and the access. Somewhere as small as Cassington, access is often the only tricky part. For outside work, also let us know about exposed walls and any outbuildings involved.
- Each joint is checked and the colour of the new sealant agreed.
- We take out the old sealant until the faces are sound.
- Closed-cell backing rod is pushed in so the sealant bonds to two sides only.
- We prime the faces where required.
- A low-modulus exterior sealant is gunned in and tooled to a neat finish.
Getting ready for the visit
- Tell us about any previous sealing or DIY attempts
- Move anything stored near the joints
- Keep pets and children clear of the area while we work
Ask for a quote
We don’t publish a price list, because every job is different. Instead, we give you a clear price for your job. To arrange one, call 0345 464 0079 or drop us an email.
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Common questions in Cassington
Will you come out to Cassington?
Yes. Cassington is within the area we cover, which takes in towns, villages and rural addresses. Our work covers London and the South East. Let us know about access, parking and anything unusual about getting there when you book.
Do you cover Cassington for external mastic?
Yes. Our work covers London and the South East, and Cassington is part of that. Just ring 0345 464 0079 or email us with a few details of the job, and we’ll send you a clear quote.
What’s an expansion joint in brickwork?
Brickwork, render and cladding all move a little, so long walls have planned gaps to take that movement. The gap is sealed with a flexible sealant over backing rod.
What do you need from me for a quote?
The location, the problem and the rough size of the job. If you can, email a few photos.
Will it make a mess?
Very little: the area around the joints is protected first, and we tidy up before we go.
I’m a tenant. Can you help?
Yes, but check with your landlord or agent first. Many landlords are glad to have it sorted.
Can a movement joint be filled with mortar?
No. Cement or mortar can’t stretch. Where a joint has been mortared, it can often be raked out and sealed properly.
How long does external mastic take?
It depends on the size of the job, but as a guide it takes a few hours for a handful of joints, longer for a whole elevation. We’ll tell you when we quote.