Oxfordshire · England
Caldecott External Mastic
Sealing brickwork movement joints, render, cladding and façade joints in Caldecott, with a one-year guarantee on every job. Ask us for a quote.
- Hard, crazed mastic that has stopped moving
- Sealant that has lost its bond to the brick or render
- Movement joints with cracked, split or missing sealant
External mastic in Caldecott, done properly
We cut out failed sealant, set the joint depth with closed-cell backing rod and reseal with a low-modulus exterior sealant. We pick a colour that sits well with the wall so the line blends in. Common call-outs are for joints pointed up with cement by mistake and rain getting behind render or cladding at a joint, on joints between brick and frames, façade panels and copings & trims.
In and around Caldecott, older properties sit alongside newer ones, each with its own outside joints. Older gutters and trims need their joints resealed; newer brick and render need their movement joints kept sound.
Big or small, it’s backed by our 12-month guarantee.
- Place
- Caldecott (OX14, OX13)
- Wider area
- Oxfordshire
- Cover
- 12 months on all our work
- Quotes
- A clear price before we start
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
FAQs for Caldecott
Can you help a landlord with a rental near Culham station?
Yes, we work for landlords and letting agents. You can phone 0345 464 0079 or drop us an email with the address and a few details, and we will give you a fixed price before work begins.
Can you do external mastic in Caldecott?
Yes. Our work covers London and the South East, and Caldecott is part of that. Just phone 0345 464 0079 or email us with a few details of the job.
Are you fully insured?
Yes. Full insurance covers our work.
Do the sealants smell?
Sometimes, a little. It fades as the sealant cures, and ventilation helps.
Can a movement joint be filled with mortar?
No. A mortar-filled joint cannot move, so the wall cracks somewhere else instead. Use a flexible sealant with backing rod.
What colours does the sealant come in?
The sealant colour is picked to suit the wall so the joint blends in. There’s a wide choice of exterior colours.
Why is there a gap in my brick wall?
Walls move with heat, cold and moisture, so long walls have planned gaps to take that movement. It’s closed with backing rod and a flexible sealant.
How often do external joints need resealing?
It varies from wall to wall: joints on exposed walls or with a lot of movement age sooner. Check them each year and reseal when they split or harden. Every job carries our 12-month guarantee.
What affects the quote in Caldecott
Every job gets its own quote. This is what makes a difference:
- The product the joint needs
- Whether the work is at height
- When we can work, for business premises
- Whether old sealant or filler has to be cut out
Commercial jobs are quoted on the same basis as homes: the amount of work, the access and the products needed, along with when we can work on site. Call for a quick quote and we will explain what it covers.
Helping us quote
The more you tell us, the more accurate the quote. When you get in contact, it helps to mention:
- A few photos by email, if you can
- How many joints, rooms or windows are involved
- Whether it has been sealed before
- What the problem is, such as mould, gaps, leaks or cracking
Every job is quoted individually. Simply phone 0345 464 0079 or email us and describe the job and send pictures if you have them.
The process
A visit follows a simple pattern: we look at the joints together, mask and protect the surrounding surfaces, do the work and clear up. Most jobs take anything from a few hours to several days, depending on the building. For a job in Caldecott, we agree the time, the access and parking before the day. If the work is outside, the weather plays a part, as sealant needs a dry surface.
- First, the joints are inspected and the access agreed.
- We cut out the old mastic and rake out anything in the joint.
- Joint faces are cleaned back and primed if the sealant needs 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
- Tell us about any previous sealing or DIY attempts
- Plan for the work area to be out of bounds to pets and children
- Let us know about stairs, lifts or work at height
Get a quote
Getting a quote is simple: let us know the job and the location and its rough size. A few photos by email make the job easier to understand, and we will take it from there.
Advice
How the job changes by surface
Cladding and façade panels
If the façade has a specified sealant, that is what we use. Tell us what the building has when you get in touch.
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.
Also near Caldecott
Other services in Caldecott
Caldecott buildings and the weather
With historic houses such as Clifton Hampden Manor (about 3.5 miles east) nearby, there’s older building stock in the area around Caldecott as well as newer homes. In older buildings, older brick and stone need a sealant that suits them, at the right joint depth. Rainfall in the South East is lower than in much of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
For site and facilities teams at buildings such as Thameside Primary School, its movement joints, gutters and trims need looking after like any other building’s. In the older streets around St Helen's Church, old and new materials meet at the roofline and walls, which is where sealant earns its keep. Rented homes near Culham station change hands often, and split movement joints are easy to miss on a rental until damp shows inside.
Caldecott is about 1 mile south of Abingdon-on-Thames, in Oxfordshire. Every kind of property in Caldecott can book us for external mastic. Every job comes with our one-year guarantee. Caldecott is one of 443 places in Oxfordshire we cover. You can also see our page for Oxford, roughly 7 miles from Caldecott.
Our applicators cover all of the OX14 and OX13 postcode area for external mastic. That includes homes and businesses on Mill Road, Baker Road and Saxton Road. If you are just outside Caldecott, we cover Culham (1 mile east), Abingdon-on-Thames (1 mile north), Sutton Courtenay (1 mile south), Milton (2 miles south) and Appleford-on-Thames (3 miles south-east). Further out, we also cover Oxford (7 miles north), Didcot (4 miles south-east), Witney (12 miles north-west), Carterton (15 miles north-west), Thame (15 miles north-east) and Wantage (7 miles south-west).
Landmarks near Caldecott
Locally, jobs take us to homes and businesses close to Albert Park, The Old Anchor Inn and John Mason School. Caldecott’s nearest station is Culham station, roughly 2.3 miles east of the centre. Well-known places in the area include Pendon Museum (3.4 miles south-east) and FitzHarris Castle (1 mile north). Open spaces near Caldecott include Dry Sandford Pit.
When something else is needed
We will not take on work that will not last, so these are the limits:
- Failed render or damaged cladding panels
- Walls that need new movement joints cut into them
- Cracked brickwork or render that needs a builder or plasterer
Not sure which it is? You can ring 0345 464 0079 or drop us an email and we’ll tell you honestly before you book.
What we seal
- Copings & trims
- Render & cladding joints
- Concrete & block
- Façade panels
- Brickwork movement joints
- Joints between brick and frames
Should I try it myself first?
If you are set on DIY, put the effort into preparation: take out all the old sealant, make sure the joint is clean and dry, and give it the full cure time. If it doesn’t work out, we can still put it right.
The difference is mostly in the preparation and the product. Joints are cleaned back to sound surfaces and dried, and the sealant is chosen for how the joint moves and where it is.
Landlord and commercial work in Caldecott
If you manage several properties in or around Caldecott, several properties can be quoted together. Send us the addresses and the work at each.
Hotels need rooms back in use, so the work can be planned room by room. Hotel work is part of what we do, alongside homes and businesses.
Aftercare tips
Joint life depends on how it’s used and looked after. We suggest:
- Show decorators and builders where the movement joints are
- Check the sealant is paintable before painting near it
- Keep high-pressure jets off the joints
- Look over the joints every year, ideally after winter
Don’t paint over the new sealant unless we’ve said the product is paintable. Many exterior sealants are not designed to be painted, and paint can crack as the joint moves.
Leave a failed movement joint and water keeps getting into the wall. That can lead to damp patches, staining and frost damage.