Oxfordshire · England
Window & door mastic in Kennington, Oxfordshire
Window mastic for Kennington and the surrounding area: careful preparation, the right product and tidy work. Call for a quick quote.
- Water coming in at the bottom corners of a door
- Rushed sealant from a window installation
- Hard, cracked sealant around windows
How we handle window mastic in Kennington
Mr Mastic’s applicators have more than 20 years’ experience with window and door sealants. We’re fully insured ARBOMaster approved applicators, and we give a 12-month guarantee on the work. We work on window sills, aluminium frames and patio & French doors, and common reasons people get in touch are damp patches on the reveal after heavy rain and black, perished sealant on frames.
Houses in smaller places like Kennington can stand more in the open than those in a built-up town. That is hard on the mastic around frames and sills.
A 12-month guarantee comes as standard.
- Location
- Kennington (OX1, OX14)
- Wider area
- Oxfordshire
- Cover
- One year on every job
- Quotes
- A clear quote up front
- Phone
- 0345 464 0079
- Page 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 job generally takes a morning for a couple of windows and a door from start to finish. Parking around Kennington is generally easier than in a town centre, but mention any lanes, gates or long drives. If the job is outside, tell us about side access and how high the joints are.
- We start by checking each window and door with you.
- We remove the old mastic and clean the frame and the wall.
- Deep gaps are filled with backing rod to set the depth.
- New exterior sealant goes on in a matching colour and is tooled smooth.
- Finally we tidy up and check each joint.
Preparing for the visit
- Mention any sign-in or site rules at work premises
- Mention any tricky access
- Try not to wet indoor joints just before the visit
Get a quote
A good description makes for an accurate quote. Let us know the location, the problem and roughly how many joints, and add pictures by email if you can.
Related advice
Work for landlords, hotels and businesses
In hotels, rooms out of use cost money, so the work can be planned room by room. Hotel work is part of what we do, alongside homes and businesses.
For anyone letting property in or around Kennington, several properties can be quoted together. Send us the addresses and the work at each, and photos by email help.
Can I do it myself?
Overfilling a joint is a classic DIY mistake. A thick, smeared bead looks untidy and doesn’t move well, and the joint depth matters as much as the finish.
If you are set on DIY, put the effort into preparation: remove every trace of old sealant, clean and dry the joint, and follow the product’s cure time. If it doesn’t work out, we can still put it right.
How we quote for window mastic
The quote reflects the job in front of us. We look at:
- Any mould that needs treating
- Any working-time requirements on site
- The old material and how stubborn it is
- How many areas need sealing
Leaving a failed joint usually makes the job bigger, not smaller, because water and mould keep working on it. If you are not sure whether it needs doing, ring 0345 464 0079 or drop us an email for an honest opinion and a quote.
What to tell us for a quote
When you contact us, these details help:
- How many joints, rooms or windows are involved
- If someone has resealed it before
- Pictures of the joints, sent by email
- The problem you’ve noticed
Call for a quick quote, or send an email if you’d rather. Tell us about the joints that need doing and we’ll explain what’s involved before giving you a price.
Towns and villages near Kennington
Also in Kennington
Your questions about window mastic in Kennington
Do you work for landlords with property near Radley station?
Yes, we work for letting agents and landlords. You can ring 0345 464 0079 or email us with the address and a few details, and we’ll give you a fixed price before we start.
Is Kennington within the area you cover?
Yes, we do. Our work covers London and the South East, and smaller places are part of that. The journey is planned ahead, so it helps to know about access.
Will the old sealant be removed?
Yes. We cut out all the old sealant and clean the joint before applying anything new.
How do I get a quote for window mastic in Kennington?
It depends on the job, so we quote each one individually. For a quick quote, phone 0345 464 0079 or email us and tell us what needs doing and where.
Do you have sealant for grey or black windows?
Yes. We can use white, brown, anthracite grey, black or clear, so the joint suits the frame.
Are you ARBOMaster approved?
Yes. We’re ARBOMaster approved, the scheme for applicators of Arbo sealants.
Is it OK to seal over old sealant?
No, because it fails. We remove every bit of old sealant first.
What should I tell you?
A short description and the location, plus photos if you have them. If we need more, we will ask.
What happens if it’s left?
Resealing frames is a short job: it takes anything from an hour or two to a full day, depending on how many frames there are. Wait for damp to appear and there may be plaster and decorating to sort out too. Homes in smaller places like Kennington 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.
A few things move the cost up or down: the old material and how easily it comes out, whether mould needs treating, and whether the work is at height. We take all of that into account in your quote.
Why us?
- White, clear, grey or another colour, product permitting
- More than 20 years in sealant work
- Sanitary silicone with an anti-fungal additive in wet areas
- Homes, businesses and hotels
Read our cost guide and what customers say.
What window mastic looks like in Kennington
With historic houses such as Holywell Manor (about 3.1 miles north) nearby, there’s older building stock in the area around Kennington as well as newer homes. In older buildings, older timber frames in brick or stone need a different approach from a modern uPVC window. Rainfall in the South East is lower than in much of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
If you look after a building such as St Swithun's CofE Primary School, the mastic around its windows and doors needs looking after like any other building’s. Rented homes near Radley station change hands often, and cracked frame mastic tends to show up as a draught or damp complaint, so it’s worth checking between lets.
Kennington is about 3 miles south of Oxford, in Oxfordshire. Every kind of property in Kennington is covered for window mastic. The work is guaranteed for a year. 443 places in Oxfordshire are on our list.
All of OX1 and OX14 is covered for window mastic, from the main roads to the quietest streets. If you need window mastic at a property on Simpsons Way, The Avenue and Liddiard Close or anywhere close by, we can help. We also cover the places around Kennington: Sandford-on-Thames (1 mile east), Littlemore (1 mile north-east), Redbridge (1 mile north), Hinksey Hill (1 mile north-west) and Bayworth (1 mile west). Within a short drive, we also cover Oxford (3 miles north), Didcot (7 miles south), Bicester (14 miles north), Abingdon-on-Thames (3 miles south-west), Witney (12 miles north-west) and Carterton (15 miles west).
Around Kennington
In Kennington, that means homes and buildings near The Oxford Academy, Emmanuel Christian School and The Tandem pub, among other places. The nearest railway station is Radley station, about 1.8 miles south of the centre. Other landmarks nearby include Templars Square (1.9 miles north-east) and Oxford Castle and earlier settlement remains (2.9 miles north). The countryside around Kennington includes Lashford Lane Fen and Harcourt Hill.
Do you need window mastic in Kennington?
Frames are never completely still. Sun on a frame makes it expand, and it contracts again overnight, while the masonry beside it stays put. If the sealant cannot stretch, it splits.
Most people get in touch when they notice something like this:
- Damp patches on the reveal after heavy rain
- Leaking joints at the ends of sills
- Draughts coming in around windows and doors
- Old mastic that has gone black or come away
In the older streets around St Swithun's Church, the windows may be timber, sash or later replacements, and each needs the right sealant against the wall.
Comparing quotes
- What happens if they find a problem under the old sealant
- What the cure time is
- What the quote includes, VAT included or not
- Whether they seal over old material or remove it
What the job involves on each surface
Window sills
Every drop off the glass ends up on the sill, so the joints at each end and underneath matter. Each is cleaned out and resealed.
Composite doors
Front doors take the weather head on, and the top and bottom corners tend to fail first. Those corners get the most care.