Oxfordshire · England
Wallingford External Mastic
We cover Wallingford for sealing brickwork movement joints, render, cladding and façade joints. Old sealant removed completely, joints prepared properly and a 12-month guarantee.
- Old sealant gone brittle and cracked
- Joints where the bead has come unstuck
- Movement joints filled with mortar instead of sealant
Can I do it myself?
Some jobs are best left to a professional: work at height, external movement joints, fire-rated sealant and large areas need the right product, the right access and the right method.
What a professional job adds is preparation and the right 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.
About our external mastic in Wallingford
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, so it bonds to the two sides only and can stretch. If you have sealant pulling away from one side of the joint and joints with sealant missing in places, we can put it right.
In and around Wallingford, older properties sit alongside newer ones, each with its own outside joints. Older homes need their gutter and trim joints kept tight, newer ones their movement joints.
Every job is covered by a one-year guarantee, wherever you are in Oxfordshire.
- Location
- Wallingford (OX10)
- Region
- Oxfordshire
- Cover
- One year on every job
- Price
- Quoted before any work starts
- Call
- 0345 464 0079
- Last updated
- 26 October 2026
Signs you need external mastic in Wallingford
Buildings move more than people expect. Brickwork grows a little over the years, blockwork and concrete shrink, and all of it moves with heat and moisture. All of that ends up in the joint sealant.
It’s worth asking for a quote if you see:
- Weeds or debris growing in open joints
- Brick movement joints where the sealant has split
- Sealant that has lost its bond to the brick or render
- Old sealant gone brittle and cracked
For an older house near a landmark such as St Mary-le-More, the joints between older walls, newer extensions and the roofline need a sealant that can move.
Questions to ask before you book
- Whether the sealant suits the joint
- What guarantee comes with the work
- What insurance they hold
- How hidden problems are handled
Surface by surface
Copings and trims
Joints in copings, parapets and trims are exposed to the worst of the weather. Each is resealed with a weatherproof, flexible sealant.
Render joints
Render has movement joints and stop beads that need sealing. They’re resealed in a sealant that suits the render.
Why it’s worth doing now in Wallingford
Mortar or ordinary filler might look like a quick way to close an open joint, but it locks the joint solid. The movement then cracks the brickwork or render nearby. The correct repair is a flexible sealant with the right backing. Homes in smaller places like Wallingford can face more weather, and failed outside joints let damp into walls. Indoors, a failed seal lets water into floors and panels as it would anywhere.
What it costs depends on the amount of work, how much old material has to come out and how easy the joints are to reach. We give a clear quote before work begins.
Why Wallingford clients choose us
- 180+ five-star Google reviews
- Sealant colour chosen to suit
- Old sealant always removed completely
- Anti-fungal silicone where joints get wet
See our cost guide or customer reviews.
What sealant work can’t fix
We will always be straight with you, so here’s what sealant cannot fix:
- Damp that is not coming from the joint
- Cutting new joints into brickwork, which is building work rather than sealant work
- Cracking across the wall rather than at a joint
If in doubt, ring 0345 464 0079 or drop us an email and we will say what we think.
Joints and surfaces we work on
- Concrete & block
- Façade panels
- Joints between brick and frames
- Render & cladding joints
- Copings & trims
- Brickwork movement joints
The process
Before we leave, we go over the finished joints with you. The visit itself usually takes anything from a few hours to several days, depending on the building, depending on the size of the job. In a smaller place like Wallingford, parking is seldom the issue; lanes, gates and long drives are worth mentioning. If the job is outside, tell us about side access and how high the joints are.
- Each joint is checked and the colour of the new sealant agreed.
- Failed sealant is removed back to clean, sound faces.
- Backing rod goes in so the sealant can stretch between the two faces.
- We prime the faces where required.
- We gun in low-modulus sealant and tool it neatly.
Preparing for the visit
- For business premises, tell us about site rules or sign-in
- Move anything stored near the joints
- Let us know about stairs, lifts or work at height
Get a quote
Getting a quote is simple: tell us what needs doing and where and its rough size. A few photos by email make the job easier to understand, and we will come back to you with a quote.
Read more
Wallingford: your questions answered
Can you help a landlord with a rental near Cholsey station?
Yes. We work for landlords and letting agents as well as householders. Just call 0345 464 0079 or drop us an email with the address and what needs doing, and we will send you a clear quote.
Can you do external mastic in Wallingford?
Yes. Our work covers London and the South East, and Wallingford is part of that. You can ring 0345 464 0079 or send us an email and let us know what needs doing, and we will give you a clear quote.
What is a movement joint?
Walls move with heat, cold and moisture, and planned joints take up that movement. The gap is sealed with a flexible sealant over backing rod.
Do you do commercial work?
Yes. We have worked for hotels, offices and other businesses and we’re fully insured.
Is it OK to fill a movement joint with cement?
No. A mortar-filled joint cannot move, so the movement cracks the wall elsewhere. Use a flexible sealant with backing rod.
How much does external mastic cost in Wallingford?
We do not publish prices, because the cost depends on the job: its size, the old material, access and the product needed. You’ll get a clear quote before work begins.
Can you do several jobs on one visit?
Yes. Tell us about everything you’d like done and you’ll get one quote.
Do you use backing rod?
The foam is closed-cell backing rod. It stops the sealant going in too deep and bonding to three sides so it can flex with the joint.
Walls and rooflines in Wallingford
Historic houses like Brightwell Manor (about 1.7 miles north-west) are a reminder that the area around Wallingford has older buildings as well as new. In older buildings, older brick and stone need a sealant that suits them, at the right joint depth. London and the South East are among the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
For site and facilities teams at buildings such as Fir Tree Junior School, movement joints, cladding joints and gutters on larger buildings need the same care as a house’s. Rented homes near Cholsey station change hands often, and split movement joints are easy to miss on a rental until damp shows inside.
Wallingford is about 5 miles east of Didcot, in Oxfordshire. Whether you’re in the middle of Wallingford or further out, we cover external mastic for every kind of property. We cover 443 towns and villages across Oxfordshire, from the larger towns to small villages. We also work in Oxford, about 11 miles from Wallingford.
All of OX10 is within our area for external mastic, from the main roads to the quietest streets. Streets in the area include Station Road, High Street and Hawthorn Close. Main roads around Wallingford include the A4130, so getting to you is simple. We also cover the places around Wallingford: Preston Crowmarsh (1 mile north-east), Mackney (1 mile west), Brightwell-cum-Sotwell (2 miles north-west), Benson (2 miles north-east) and Shillingford (2 miles north). We also work in nearby towns such as Oxford (11 miles north-west), Didcot (5 miles west), Abingdon-on-Thames (8 miles north-west), Thame (12 miles north-east), Wantage (13 miles west) and Henley-on-Thames (11 miles south-east).
Landmarks near Wallingford
In Wallingford, that means homes and buildings near Wallingford School, Wallingford School and The Cross Keys Public House. The closest station to Wallingford is Cholsey station, roughly 2.4 miles south-west of the centre. Other landmarks nearby include Wallingford Castle (within half a mile east). Not far away are Wittenham Clumps and Cholsey Marsh.
How to look after the new joints
After the cure time, these simple habits help:
- Check external joints each spring
- Act on the first splits you see
- Leave the joints unpainted unless we’ve said otherwise
- Make sure movement joints are not pointed over
Only paint over the joint if we’ve confirmed the sealant can take paint. Paint can crack on a flexible joint, and paint can crack as the joint moves.
If you can see gaps, plants or bare sections in a joint, have it checked. Earlier resealing means a smaller job and a better result.