Oxfordshire · England
External & façade joints in Mongewell, Oxfordshire
Sealing brickwork movement joints, render, cladding and façade joints for homeowners, landlords and businesses in Mongewell. Fully insured, ARBOMaster approved and guaranteed for a year.
- Plants rooting in failed movement joints
- Brick movement joints where the sealant has split
- Gaps where render, brick and frames meet
Why act early in Mongewell
Sealing over the top of old mastic doesn’t hold for long. New sealant doesn’t bond well to old, weathered sealant, so we always take the old sealant out. In a small place like Mongewell, homes can be exposed to wind and rain, which finds any gap, and older walls, once damp, take a long time to dry.
What you pay reflects the work, not guesswork. That is why we ask a few questions first and send you a clear quote before any work starts.
Why choose Mr Mastic in Mongewell
- Domestic, commercial and hotel work
- Quality sealants from Arbo and Everbuild
- Old sealant always removed completely
- You choose the colour before work begins
Read how sealant jobs are priced and our reviews.
External mastic in Mongewell, done properly
We cut out failed sealant, set the joint depth with closed-cell backing rod and reseal with a low-modulus exterior sealant. The colour is chosen to suit the brick or render so the joint does not stand out. Common call-outs are for failed sealant between panels on a façade and brick movement joints where the sealant has split, across façade panels, brickwork movement joints and concrete & block.
Somewhere as small as Mongewell, homes and farm buildings often face open ground, so walls and rooflines take the full force of wind and rain. Joints on those walls need a sealant that moves with the building and stays in place.
There’s a 12-month guarantee on every job.
- Location
- Mongewell (OX10)
- Wider area
- Oxfordshire
- Cover
- 12 months on all our work
- Quotes
- A clear quote up front
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
What happens on the day
On the day, there’s very little for you to do. Show us the job and we’ll take it from there. The work itself takes a few hours for a handful of joints, longer for a whole elevation, including the tidy-up. In a small place like Mongewell, access is normally the main thing to plan. If the job is outside, mention outbuildings, exposed walls and how to reach them.
- We start by walking round the building and agreeing the joints and the access.
- 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.
Before we arrive
- Tell us about access, such as stairs, a lift or high-level joints
- For business premises, tell us about site rules or sign-in
- Tell us about any previous sealing or DIY attempts
Get a quote
We do not publish a price list, because every job is different. Instead, we give you a clear price for your job. To arrange one, call 0345 464 0079 or email us.
Advice
Work for landlords, hotels and businesses
We work for landlords and agents as well as householders. Resealing between tenancies is a simple way to keep a property in good order before the next move-in.
We also work for property managers and facilities teams. We can quote a run of properties together.
Mongewell questions
Do you work for landlords with property near Cholsey station?
Yes, landlords and agents are among the people we work for. You can ring 0345 464 0079 or email us with the details for a clear quote.
Can you do external mastic in Mongewell?
Yes, Mongewell is within the area we cover. Our work covers London and the South East. Just ring 0345 464 0079 or drop us an email with a few details of the job.
Will the new joint stand out?
There’s a good range of exterior colours, including greys, browns, whites and stone tones. We choose the closest to your brick or render so it doesn’t stand out.
Is it OK to seal over old sealant?
No. Fresh sealant does not stick to old sealant, and anything trapped underneath, including mould and water, stays there. It all has to come out first.
Is it worth trying it myself?
Sometimes. The key is preparation: remove all the old material and work on a clean, dry joint. If it doesn’t work out, we can redo it.
Will there be a smell?
It depends on the product. Some smell for a while, some hardly at all, and any smell fades as they cure.
How long before the joint can be used?
It depends on the product and the temperature. Before we leave, we will tell you the cure time.
Does someone need to be in?
It depends on the job. Inside work needs someone to give us access.
When to call us in Mongewell
Weeds, moss and debris in a joint are a sign the sealant has gone. Dirt and roots then trap moisture in the joint and speed up the damage.
Common reasons people contact us include:
- Failed sealant between panels on a façade
- Brick movement joints where the sealant has split
- Weeds or debris growing in open joints
- Movement joints filled with mortar instead of sealant
For site and facilities teams at buildings such as Crowmarsh Gifford Church of England School, larger buildings have long runs of movement joint that eventually need resealing.
What your quote should include
- How long the guarantee is
- What the cure time is
- Which sealant they’ll use, and why
- Whether all the old sealant comes out first
Honest limits
To be straight with you, there are a few things sealant won’t fix:
- Adding movement joints to masonry that has none
- Cracks in the bricks or render themselves, away from the joints
- Failed render or damaged cladding panels
Not sure which it is? You can phone 0345 464 0079 or send us an email and we’ll tell you honestly before booking.
Surfaces we seal
- Concrete & block
- Brickwork movement joints
- Copings & trims
- Façade panels
- Render & cladding joints
- Joints between brick and frames
Surface by surface
Joints between dissimilar materials
Where a frame or panel meets masonry, water often finds a way in. We cut out the old sealant and reseal with a product suited to both surfaces.
Copings and trims
A failed coping joint lets water into the top of the wall. Sealing them early saves the wall below.
Mongewell buildings and the weather
Compared with the north and west, the South East gets less rain, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast. Historic houses like Brightwell Manor (about 2.6 miles north-west) are a reminder that the area around Mongewell 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.
Letting a property close to Cholsey station? Then outside joints that have cracked can let damp into a rental, so check them between lets. In the older streets around St Mary's Church, older walls, gutters and the joints where extensions meet them need a flexible sealant.
Mongewell is about 6 miles east of Didcot, in Oxfordshire. For external mastic in and around Mongewell, please phone 0345 464 0079 or drop us an email for a quick quote. We are based in Crawley and cover Oxfordshire. Mongewell is one of 443 places in Oxfordshire where we work. There’s also a page for Reading, roughly 12 miles from Mongewell.
We cover every part of the OX10 postcode area for external mastic. External mastic is available to properties on Hasthorpe Road, Shuttleworth Close and Elizabeth Road and the roads around them. Neighbouring places we cover for external mastic include Newnham Murren (1 mile north), Crowmarsh Gifford (1 mile north-east), Winterbrook (1 mile south-west), North Stoke (1 mile south) and Cholsey (2 miles south-west). We also work in nearby towns such as Oxford (12 miles north-west), Didcot (6 miles west), Abingdon-on-Thames (9 miles north-west), Thame (12 miles north-east), Wantage (13 miles west) and Henley-on-Thames (10 miles south-east).
Landmarks near Mongewell
In Mongewell, that means homes and buildings near Wallingford School, Wallingford School and The Old Nags Head pub, among other places. For rail, the closest station is Cholsey station, roughly 2.2 miles south-west of the centre. Other landmarks nearby include Wallingford Castle (0.9 miles north). Green spaces nearby include Wittenham Clumps and Cholsey Marsh.
Places near Mongewell
What else we do in Mongewell
How we quote for external mastic
Every job gets its own quote. This is what makes a difference:
- Working hours on commercial sites
- The type of sealant required
- How much old sealant there is and how hard it is to remove
- Mould in or behind the old joints
Rather than a set price list, we price the job in front of us: how many joints, what’s in them now and how we reach them. You will know the price before we begin.
Helping us quote
To help us quote quickly, let us know:
- What’s wrong with the joints now
- How many joints, rooms or windows are involved
- Pictures of the joints, sent by email
- Whether it’s a home or a business
For external mastic in Mongewell, ring 0345 464 0079 or send us an email. A short description of the job and where it is helps us quote, and you will get a clear quote before any work starts.