Oxfordshire · England
Somerton External Mastic
External mastic in Somerton from a team with over 20 years’ experience. Rated 4.9 on Google from 180+ five-star reviews.
- Panel joints letting water in
- Moss and dirt in joints with no sealant left
- Weathered mastic that no longer stretches
Do you need external mastic in Somerton?
UV, rain and frost all age exterior sealant. In time it goes hard, crazes on the surface and stops stretching, so the joint eventually tears or comes away from one side.
If you can see any of these, it’s time to have the joints looked at:
- Movement joints filled with mortar instead of sealant
- Movement joints with cracked, split or missing sealant
- Moss and dirt in joints with no sealant left
- Weathered mastic that no longer stretches
Letting a property close to Heyford station? Then outside joints that have cracked can let damp into a rental, so check them between lets.
Questions to ask before booking
- How long to leave it before use
- What preparation is included
- Whether they’re fully insured
- Who turns up on the day
External mastic in Somerton
A movement joint is a deliberate break that lets a wall expand and contract. The sealant in it has to stretch and squeeze for years, and when it fails, the wall takes the strain and water finds a way in. Typical jobs include brick movement joints where the sealant has split and water getting into walls through failed joints, across façade panels, brickwork movement joints and copings & trims.
Outside joints can only be sealed when they’re dry, so work in Somerton 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.
- Place
- Somerton (OX25)
- Wider area
- Oxfordshire
- Guarantee
- 12 months on all our work
- Quotes
- A clear quote up front
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
Common questions in Somerton
Will you come out to Somerton?
Yes. Somerton is within the area we cover, which takes in towns, villages and rural addresses. Our work covers London and the South East. Just mention lanes, gates or anything else about the route when you book.
Do you cover Somerton for external mastic?
Yes, Somerton is within the area we cover. We work across London and the South East. You can phone 0345 464 0079 or email us and tell us what needs doing.
What is backing rod for?
We fit closed-cell backing rod wherever the joint depth needs controlling. It controls the depth and stops the sealant bonding to the back, so the joint can move.
Can I do it myself?
Some simple jobs can be done by a careful DIYer. Most DIY failures come from sealing over old material, wet joints or too much sealant.
How long does external mastic take?
As a guide, most jobs take anything from a few hours to several days, depending on the building. Bigger jobs take longer, and we’ll say how long yours will take.
Can you match the colour of my brickwork?
Exterior sealants are made in a range of colours, from greys and browns to whites and stone shades. We choose the closest to your brick or render so the joint does not draw the eye.
Do the sealants smell?
Possibly a little. Any smell clears as the sealant cures.
Do you remove the old sealant?
Yes, every time. New sealant won’t bond properly to old, so the joint is cleaned back first.
Should I try it myself first?
Not every job suits DIY: high-level joints, fire-rated gaps, external movement joints and big jobs need the right product, the right access and the right method.
Too much sealant is as bad as too little. A thick, smeared bead looks untidy and doesn’t move well, and the joint depth matters as much as the finish.
Honest limits
In fairness, there are a few things sealant will not fix:
- Failed render or damaged cladding panels
- Damp that isn’t coming from the joint
- Cracked brickwork or render that needs a builder or plasterer
If in doubt, call 0345 464 0079 or send us an email and we will say what we think.
What we seal
- Copings & trims
- Concrete & block
- Façade panels
- Brickwork movement joints
- Joints between brick and frames
- Render & cladding joints
How the visit works
We bring everything the job needs with us. After a quick look at the joints together, the area is protected and the work begins. It normally takes anything from a few hours to several days, depending on the building. Somewhere like Somerton needs a little journey planning: tell us about narrow lanes, gates, long drives and where we can park. Everything for the job comes with us, so a second trip is avoided where possible.
- We look at every joint and agree a colour to suit the wall.
- Failed sealant is removed back to clean, sound faces.
- Backing rod goes in so the sealant can stretch between the two faces.
- Primer is applied wherever the sealant needs it.
- A low-modulus exterior sealant is gunned in and tooled to a neat finish.
Before we arrive
- Where the joints are inside, avoid wetting them before we arrive
- Mention any sign-in or site rules at work premises
- Let us know about parking restrictions
Getting a quote
Asking for a quote is easy: let us know the job and the location. Photos by email help us understand the job.
Read more
Looking after it afterwards
To keep the joints looking good and working properly:
- Never let anyone fill a movement joint with mortar
- Fix overflowing gutters above sealed joints
- Have failed joints looked at early
- Do not let climbing plants root in the sealant
Give the sealant the cure time we tell you before anything rubs against it. Most exterior sealants skin fast but take longer to cure right through.
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.
How we quote for external mastic
We quote each job individually. This is what makes a difference:
- How much old sealant there is and how hard it is to remove
- The type of sealant required
- The amount of work
- When we can work, for business premises
Rather than a set price list, we price the job in front of us: the amount of work, the old material and the access. You will know the price before we begin.
What we need to know
Before you ask for a quote, have a think about:
- Whether it has been sealed before
- Access, such as stairs, a lift or height
- What the problem is, such as mould, gaps, leaks or cracking
- Pictures of the joints, sent by email
It all starts with a short chat. Tell us what’s wrong, where it is and how much there is, and we’ll explain how we’d tackle it. Whenever you are ready, ring 0345 464 0079 or drop us an email.
What the job involves on each surface
Joints between dissimilar materials
Each side of the joint may need its own preparation. Both surfaces are cleaned and primed as the product requires.
Render joints
Render has movement joints and stop beads that need sealing. They’re resealed in a sealant that suits the render.
Places near Somerton
More services for Somerton
External mastic in Somerton: local notes
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 an older house near a landmark such as Church of St James, an extension built onto an older house moves differently, and the joint between them takes the strain.
Somerton is about 6 miles north-west of Bicester, in Oxfordshire. Across the OX25 area, we can carry out external mastic at your property. 443 places in Oxfordshire are on our list, from the larger towns to small villages. We also work in Oxford, about 14 miles from Somerton.
All of OX25 is covered for external mastic. Whether your property is on Water Street, Wharf Lane and Ardley Road or anywhere close by, our applicators can take on the job. Neighbouring places we cover for external mastic include Fritwell (2 miles east), Clifton (2 miles north), Upper Heyford (2 miles south), Souldern (2 miles north-east) and Lower Heyford (3 miles south). Further out, we also cover Oxford (14 miles south), Banbury (8 miles north), Bicester (6 miles south-east), Witney (15 miles south-west), Kidlington (9 miles south) and Headington Quarry (14 miles south).
What’s near Somerton
The nearest railway station is Heyford station, about 2.7 miles south of the centre. Nearby you’ll also find Deddington Castle (2.4 miles north-west).