Oxfordshire · England
External Mastic in Cholsey
Sealing brickwork movement joints, render, cladding and façade joints for homes and businesses in Cholsey and across Oxfordshire. Fully insured, ARBOMaster approved and guaranteed for a year.
- Failed sealant between panels on a façade
- Joints where the bead has come unstuck
- Damp patches traced to an open external joint
Should I try it myself first?
If you’ve already had a go yourself, that is fine. We remove it and do the joint properly, so tell us about it when you ask for a quote.
Sealing over old silicone is the commonest DIY error. Silicone does not stick to old silicone, so it lifts and traps water and mould underneath. All the old material has to come out first.
External mastic in Cholsey
Getting the depth right is half the job. Backing rod controls how deep the sealant goes and keeps it off the back of the joint, leaving it bonded to two faces so it can move with the wall. We are often asked to deal with movement joints with cracked, split or missing sealant and sealant that has lost its bond to the brick or render, on façade panels, concrete & block and copings & trims.
Homes around Cholsey range from older cottages to newer houses, with walls and rooflines of every type. Older gutters and trims need their joints resealed; newer brick and render need their movement joints kept sound.
The work is guaranteed for twelve months. If something is not right with it in that time, tell us and we will put it right.
- Place
- Cholsey (OX10)
- Wider area
- Oxfordshire
- Guarantee
- A year, on every job
- Quotes
- Quoted before any work starts
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
How the job changes by surface
Brickwork movement joints
Vertical joints in long brick walls let the brickwork expand without cracking. We reseal them with a low-modulus sealant over backing rod coloured to suit the wall.
Copings and trims
Metal and stone copings both move with temperature, so the joints need a sealant that stays flexible.
Cholsey buildings and the weather
Historic houses like Brightwell Manor (about 2.9 miles north) are a reminder that the area around Cholsey has older buildings as well as new. 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, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
Schools such as Cholsey Primary School are buildings too, and larger buildings have long runs of movement joint that eventually need resealing. Rented homes near Cholsey station change hands often, and failed wall and movement joints let damp in, so they’re worth checking between tenancies.
Cholsey is about 5 miles south-east of Didcot, in Oxfordshire. Wherever you are in the OX10 postcode area, we cover external mastic for homes and businesses. We cover 443 towns and villages across Oxfordshire, large and small. Our Reading page covers work nearby.
Work in OX10 works the same way as everywhere else we cover. If you need external mastic at a property on Station Road, Church Road and Lapwing Lane or a nearby road, our applicators can take on the job. Close by, we work in Winterbrook (1 mile north-east), North Stoke (1 mile east), Moulsford (1 mile south), South Stoke (2 miles south) and Mongewell (2 miles north-east). We also work in nearby towns such as Oxford (13 miles north), Didcot (5 miles north-west), Abingdon-on-Thames (9 miles north-west), Thame (14 miles north-east), Wantage (12 miles west) and Henley-on-Thames (11 miles east).
Around Cholsey
Around Cholsey, our work takes us to homes and buildings near Wallingford School, Cranford House School and Morning Star pub. Cholsey has its own railway station: Cholsey station. Nearby you’ll also find Wallingford Castle (2.4 miles north-east). For a walk, there’s Cholsey Marsh and Wittenham Clumps.
FAQs for Cholsey
Do you cover smaller places like Cholsey?
Yes, smaller places are covered as well as towns. Our work covers London and the South East. Just mention lanes, gates or anything else about the route when you book.
Do you work for landlords with property near Cholsey station?
Yes, we work for letting agents and landlords. You can phone 0345 464 0079 or send us an email with the address and a few details, and we’ll give you a fixed price before work begins.
How long should I leave it?
That depends on the sealant used, so please follow the time we give you.
Can you reach joints on upper floors?
Each building is different. Tell us the height, the number of joints and what’s below them and we will confirm how they can be reached safely.
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.
Are you insured?
Yes. We’re fully insured.
Is there a guarantee?
Yes, for a year. If there’s a problem with our work in that time, tell us and we will put it right.
What sealant do you use?
Products from Arbo and Everbuild, among others, picked for each joint. We explain the product when we quote.
What affects the cost of external mastic
Your quote is based on your job. We take into account:
- Access and height
- Any mould that needs treating
- The size of the job
- Any working-time requirements on site
Commercial jobs are quoted on the same basis as homes: how much there is to do, how we reach it and what it needs, plus any working-time requirements on site. Ask us for a quote and we’ll go through it with you.
Asking for a quote
When you contact us, these details help:
- The type of property
- Photos by email, if that’s easy
- Any previous sealing or DIY work
- Access, such as stairs, a lift or height
Need a quote? Please ring 0345 464 0079 or email us with a few details. You’ll know what we plan to do, and what it will cost, before any work begins.
Looking after it afterwards
So the new joints stay in good condition:
- Keep movement joints as flexible joints, not mortar
- Keep high-pressure jets off the joints
- Act on the first splits you see
- Leave the joints unpainted unless we have said otherwise
Do not paint over the new sealant unless we have said the product is paintable. Many exterior sealants aren’t designed to be painted and spoil the finish.
Once a joint cannot move, the wall finds another way, usually as cracking in the brickwork or render nearby. Resealing it early helps prevent that.
When to call us in Cholsey
Using the wrong sealant is another common reason. A stiff, general-purpose sealant cannot cope with a joint that moves a lot, so it pulls away from the edges.
People normally contact us when they notice one of these:
- Joints where the bead has come unstuck
- Joints with sealant missing in places
- Panel joints letting water in
- Damp patches traced to an open external joint
For an older house near a landmark such as Church of St Mary, old and new materials meet at the roofline and walls, which is where sealant earns its keep.
Before you book anyone
- Is VAT in the price?
- What happens if they find a problem under the old sealant
- What the cure time is
- Whether all the old sealant comes out first
The process
On the day, we start by going over the job with you. We protect the surfaces around the joints before any work begins. The work normally takes anything from a few hours to several days, depending on the building. A visit to Cholsey 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.
- We look at every joint and agree a colour to suit the wall.
- 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.
Preparing for the visit
- Clear the area around the work
- For indoor joints, keep the area dry beforehand if you can
- Let us know about stairs, lifts or work at height
Getting a quote
Asking for a quote is easy: tell us what needs doing and where and its rough size. Photos by email help us understand the job, and we’ll take it from there.
Advice
When something else is needed
A few problems are outside what sealant work can do:
- Structural movement, which needs a surveyor or engineer
- Walls that need new movement joints cut into them
- Cracking across the wall rather than at a joint
If you’re not sure, just phone 0345 464 0079 or email us and we’ll give you a straight answer before booking.
Surfaces we seal
- Joints between brick and frames
- Render & cladding joints
- Concrete & block
- Brickwork movement joints
- Façade panels
- Copings & trims