Oxfordshire · England
External Mastic in Eynsham
Specialist external mastic for Eynsham: the right sealant, proper preparation and a neat finish. Ask us for a quick quote.
- Joints with sealant missing in places
- Rain getting behind render or cladding at a joint
- Rigid filler in a joint that should flex
Can I do it myself?
A DIY attempt doesn’t rule out a professional job. We remove it and do the joint properly.
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.
About our external mastic in Eynsham
Getting the depth right is half the job. Closed-cell backing rod sets the depth and stops the sealant sticking to the back, so it bonds to the two sides only and can stretch. Common call-outs are for joints pointed up with cement by mistake and moss and dirt in joints with no sealant left, on render & cladding joints, brickwork movement joints and concrete & block.
Houses in smaller places like Eynsham can stand more in the open than those in a built-up town, so exposed walls and rooflines take more wind-driven rain. That’s where gutter joints and wall joints tend to fail first.
Whatever the size of the job, you get the same one-year guarantee in Eynsham and across Oxfordshire.
- Place
- Eynsham (OX29)
- Region
- Oxfordshire
- Guarantee
- One year on every job
- Quotes
- A clear price before we start
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
What we’re called out for in Eynsham
A lot of failed joints come down to preparation: dusty or wet faces, no primer where one was needed, or old sealant left in. The new sealant then lets go long before it should.
Common reasons people contact us are:
- Joints where the bead has come unstuck
- Hard, crazed mastic that has stopped moving
- Cracked joints where brick meets render or frames
- Brick movement joints where the sealant has split
For site and facilities teams at buildings such as Bartholomew School, movement joints, cladding joints and gutters on larger buildings need the same care as a house’s.
Comparing quotes
- Which sealant they’ll use, and why
- Whether they’re fully insured
- What happens if the job turns out different
- How long to leave it before use
Your questions about external mastic in Eynsham
Is Eynsham in your area for external mastic?
Yes. Our work covers London and the South East, and Eynsham is part of that. You can call 0345 464 0079 or email us and tell us what needs doing.
Will you come out to Eynsham?
Yes. Eynsham is within the area we cover, which takes in towns, villages and rural addresses. We work across London and the South East. Let us know about access, parking and anything unusual about getting there when you book.
Will the old sealant be removed?
Yes, every time. New silicone does not stick to old silicone, so any old material comes out before anything new goes in.
Are you an approved applicator?
Yes. ARBOMaster is the approved applicator scheme for Arbo sealants, and we are part of it.
How long does external mastic take?
Typically it takes anything from a few hours to several days, depending on the building. Bigger jobs take longer.
Should I try DIY first?
You can, for simple jobs. Preparation is everything: all the old sealant out, and a clean, dry joint. We can always put it right if it fails.
Do you work at height?
It depends on the height and the site. Low-level joints are straightforward; for higher ones, send details and we will confirm the access.
Where is Mr Mastic based?
We work from Crawley. We cover Eynsham and the rest of Oxfordshire, along with the rest of our area.
Work for landlords, hotels and businesses
In hotels, rooms out of use cost money, so the work can be planned room by room around your bookings where we can. We’ve worked in hotels as well as homes and businesses.
If you manage several properties in or around Eynsham, several properties can go on one quote. Send us the addresses and the work at each.
Looking after it afterwards
After the cure time, these simple habits help:
- Tell anyone working on the walls about the movement joints
- Keep water from gutters off the wall
- Act on the first splits you see
- Check the sealant is paintable before painting near it
Have a quick look at the joints each spring. Watch for splits, edges coming away or growth in the joint.
Small splits are the time to act. At that stage it’s a simple cut out and reseal with no damage behind it to deal with.
Also near Eynsham
Also in Eynsham
How the job changes by surface
Copings and trims
Coping joints that leak let water straight down into the wall. Sealing them early saves the wall below.
Joints between dissimilar materials
Different materials may need different primers. Both surfaces are cleaned and primed as the product requires.
How the visit works
We work through the job in order: protection first, then preparation, sealing and a tidy-up. For most jobs that takes a few hours for a handful of joints, longer for a whole elevation. A visit to Eynsham is planned like any other: the time, the access and where to park are agreed in advance. Outdoor jobs depend on a dry day, since sealant needs a dry surface.
- First, the joints are inspected and the access agreed.
- Every bit of old sealant and any mortar or debris is cut out.
- The faces are brushed clean and primed where the product requires it.
- We fit closed-cell backing rod to control the depth.
- We apply the sealant, tool it and check the whole run.
Getting ready for the visit
- Try not to wet indoor joints just before the visit
- Mention any parking rules near the property
- Keep pets and children clear of the area while we work
How to get a quote
There’s no standard price list, because every job is different. Instead, your job gets its own clear quote. To get started, ring 0345 464 0079 or send us an email.
Related advice
Eynsham buildings and the weather
Rainfall in the South East is lower than in much of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day. With historic houses such as Blenheim Palace (about 4.1 miles north) nearby, there’s older building stock in the area around Eynsham as well as newer homes. In older buildings, older walls and rooflines need a sealant that moves with them and suits the material.
For an older house near a landmark such as Church of St Leonard, old and new materials meet at the roofline and walls, which is where sealant earns its keep. If you let a flat or house near Hanborough station, failed wall and movement joints let damp in, so they’re worth checking between tenancies.
Eynsham is about 5 miles east of Witney, in Oxfordshire. Whether you’re in the middle of Eynsham or further out, we cover external mastic for every kind of property. Eynsham is one of 443 towns and villages in Oxfordshire we cover. Oxford is on our list too, around 7 miles away.
Our applicators cover all of OX29 for external mastic and the streets around it. If you need external mastic at a property on High Street, Station Road and Back Lane or a nearby road, our applicators can take on the job. We also cover the places around Eynsham: Swinford (1 mile south-east), Cassington (2 miles north-east), Farmoor (2 miles south-east), Sutton (2 miles south-west) and Filchampstead (3 miles south-east). Larger places within reach include Oxford (7 miles east), Didcot (13 miles south-east), Bicester (13 miles north-east), Abingdon-on-Thames (8 miles south-east), Witney (5 miles west) and Carterton (9 miles west).
Near you in Eynsham
Locally, jobs take us to homes and businesses close to The Jolly Sportsman Public House And Attached Outbuildings and Eynsham Community Primary School. The nearest railway station is Hanborough station, about 2.9 miles north of the centre. Other landmarks nearby include Radcliffe Infirmary (5.1 miles east) and Oxford Bus Museum (3 miles north). Not far away are Cumnor Hill and Hook Meadow and The Trap Grounds.
What sealant work cannot fix
A few problems are outside what sealant work can do:
- Cutting new joints into brickwork, which is building work rather than sealant work
- Cracking across the wall rather than at a joint
- Render that is blown, hollow or coming away
If in doubt, phone 0345 464 0079 or email us and we’ll say what we think.
Surfaces we seal
- Façade panels
- Joints between brick and frames
- Concrete & block
- Copings & trims
- Render & cladding joints
- Brickwork movement joints