Oxfordshire · England
Sunnymead External Mastic
External mastic across Sunnymead and nearby, with every bit of old sealant taken out first and a one-year guarantee.
- Water getting into walls through failed joints
- Joints pointed up with cement by mistake
- Joints with sealant missing in places
What external mastic looks like in Sunnymead
London and the South East are among the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast. Historic houses like Holywell Manor (about 2.1 miles south) are a reminder that the area around Sunnymead 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.
Letting a property close to Oxford Parkway station? Then outside joints that have cracked can let damp into a rental, so check them between lets. In the older streets around Roman Catholic Church of St Gregory and St Augustine, older walls, gutters and the joints where extensions meet them need a flexible sealant. Schools such as Cutteslowe Primary School are buildings too, and movement joints, cladding joints and gutters on larger buildings need the same care as a house’s.
Sunnymead is about 3 miles north-west of Oxford, in Oxfordshire. If you need external mastic in Sunnymead, please ring 0345 464 0079 or send us an email for a quick quote. We are based in Crawley and cover Oxfordshire. Sunnymead is one of 443 places in Oxfordshire we cover for external mastic.
We cover every part of the OX2 postcode area for external mastic and the streets around it. Streets in the area include Wren Road, Scott Road and Wyatt Road, all of which we cover. Sunnymead is on the A4165, so it’s easy for us to get to. Other places close to Sunnymead include Cutteslowe (1 mile north), Summertown (1 mile south), North Oxford (1 mile south), Wolvercote (1 mile west) and Park Town (1 mile south). We also work in nearby towns such as Oxford (3 miles south-east), Didcot (12 miles south), Bicester (9 miles north-east), Abingdon-on-Thames (7 miles south), Witney (10 miles west) and Carterton (14 miles west).
Landmarks near Sunnymead
We work in homes and buildings around St Hugh's College Main Building Including Library, Oxford University Parks and Dew Drop Inn and the streets around them. Other local landmarks include Summer Fields School (0.5 miles south) and Oxford Academy (0.7 miles south). The closest station to Sunnymead is Oxford Parkway station, roughly 1.4 miles north of the centre. Well-known places in the area include Oxford Castle (2.3 miles south) and Oxford University Museum of Natural History (1.8 miles south). For a walk, there’s Hook Meadow and The Trap Grounds and Headington Hill.
About our external mastic in Sunnymead
Movement joints let brickwork, render and cladding expand and shrink without cracking. Its sealant has to flex with the building, season after season, and when it fails, the wall takes the strain and water finds a way in. We work on joints between brick and frames, concrete & block and copings & trims, and people most often call us about rain getting behind render or cladding at a joint and hard, crazed mastic that has stopped moving.
In a smaller place like Sunnymead, some homes face open ground, and walls and rooflines facing the weather take the worst of it. That’s where gutter joints and wall joints tend to fail first.
The work is covered for a year after we finish. If there’s a problem with it, please call 0345 464 0079 or email us.
- Location
- Sunnymead (OX2)
- Region
- Oxfordshire
- Guarantee
- One year on every job
- Quotes
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
Should I try it myself first?
Sealing over old silicone is the commonest DIY error. New silicone will not bond to old, so it peels away and traps moisture behind it. Everything old must be removed first.
The difference is mostly in the preparation and the product. We take joints back to clean, dry surfaces, and the sealant is matched to the joint and its conditions, then guaranteed for a year.
Aftercare tips
Aftercare is simple, and it makes a real difference:
- Deal with leaking gutters that soak the joints below
- Wash walls gently around the sealant
- Never let anyone fill a movement joint with mortar
- Point out the joints to other trades
Have a quick look at the joints each spring. Splits, gaps at the edges or plants in the joint are early warning signs.
A joint that has stopped moving pushes the movement elsewhere, generally as cracking in the brickwork or render nearby. Catch it early and you reduce the risk.
Surface by surface
Joints between dissimilar materials
Different materials may need different primers. We prepare both faces so the sealant bonds properly.
Concrete and blockwork
The face of concrete or block is often dusty, so preparation is key. A primer goes on where the product requires one before the bead.
What happens on the day
On the day, we start by going over the job with you, so you know exactly what we are doing. We protect the surfaces around the joints before any work begins. The work generally takes a few hours for a handful of joints, longer for a whole elevation. Parking around Sunnymead is normally easier than in a town centre, but mention any lanes, gates or long drives. For outside work, side access and the height of the joints help us plan.
- 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.
- We gun in low-modulus sealant and tool it neatly.
Before we arrive
- Clear the area around the work
- Keep pets and children clear of the area while we work
- Tell us about any water getting in
Get a quote
There’s no standard price list, because every job is different. Instead, your job gets its own clear quote. To arrange one, ring 0345 464 0079 or email us.
Related advice
What affects the cost of external mastic
There’s no set price list. What we look at:
- The number and length of the joints
- The number of rooms or windows
- When we can work, for business premises
- Whether the work is at height
The cost depends on the size of the job, how much old material has to come out and how easy the joints are to reach. You will have a clear quote before any work starts.
Helping us quote
You do not need to know the technical terms. It helps if you can tell us:
- Access, such as stairs, a lift or height
- If someone has resealed it before
- Pictures of the joints, sent by email
- The type of property
For external mastic in Sunnymead, ring 0345 464 0079 or email us. Tell us what the problem is and where, and you will get a clear quote before work begins.
When it isn’t the sealant
We’d rather tell you now than do work that will not last, so here’s what sealant can’t put right:
- Movement that’s more than a sealant joint can take
- Cracked brickwork or render that needs a builder or plasterer
- Rising or penetrating damp from elsewhere in the wall
Not sure which it is? You can call 0345 464 0079 or drop us an email and we will tell you honestly before you book.
Surfaces we seal
- Concrete & block
- Façade panels
- Joints between brick and frames
- Render & cladding joints
- Brickwork movement joints
- Copings & trims
Also near Sunnymead
What else we do in Sunnymead
Sunnymead: your questions answered
I let a flat near Oxford Parkway station. Can you help?
Yes. We work for landlords and agents as well as householders. You can call 0345 464 0079 or send us an email with the details for a clear quote.
Do you cover Sunnymead for external mastic?
Yes. Our work covers London and the South East, and Sunnymead is part of that. You can ring 0345 464 0079 or send us an email and tell us what needs doing, and we’ll give you a clear quote.
How long does external mastic last?
It varies with how exposed the wall is and how much the joint moves. Look for splits, hardening or edges coming away and have them redone then.
Do you guarantee your work?
Yes, always. There’s a 12-month guarantee on every job, large or small.
Is it worth trying it myself?
For a simple, easy-to-reach joint, a careful DIYer can do a reasonable job. The usual mistakes are sealing over old sealant, sealing a damp joint and using too much.
Do you use backing rod?
We fit closed-cell backing rod wherever the joint depth needs controlling. It controls the depth and stops the sealant bonding to the back.
Do you hold any approvals?
Yes. We are an ARBOMaster approved applicator.
How long will you be here?
A typical job takes anything from a few hours to several days, depending on the building. Your quote will say how long we expect yours to take.
For landlords and businesses
We also work for property managers and facilities teams. Several sites can be quoted together, and we’re fully insured.
Failed sealant is one of the commonest items on a check-out report, and it’s easy to sort out between tenants. We can quote for more than one property at once.