Oxfordshire · England
Window Mastic in Cumnor
Window mastic in Cumnor from a team with over 20 years’ experience. Rated 4.9 on Google from 180+ five-star reviews.
- Mastic that’s falling out in pieces
- Water coming in at the bottom corners of a door
- Draughts coming in around windows and doors
How we handle window mastic in Cumnor
A cold draught around a closed window often comes from the frame edge. Resealing that joint can make a room feel noticeably less draughty. Where the air is getting in through the window itself, we’ll say so. If you have water coming in at the bottom corners of a door and cracked internal joints between frame and plaster, we can put it right, on patio & French doors, uPVC windows and composite doors alike.
Around Cumnor, many homes face open ground, so their windows and doors take the full weather. Exposed frames and sills lose their mastic sooner than sheltered ones.
The work is guaranteed for twelve months. If there’s a problem with our work within the year, let us know and we will sort it.
- Location
- Cumnor (OX2)
- Wider area
- Oxfordshire
- Cover
- One year on every job
- Quote
- Quoted before any work starts
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
Quotes for window mastic in Cumnor
The price is agreed before any work begins. It’s based on:
- The size of the job
- How easy the joints are to reach
- The type of sealant required
- Whether there’s mould to deal with
Leaving a failed joint usually makes the job bigger, not smaller. If you are not sure whether it needs doing, ring 0345 464 0079 or email us and we will give you an honest view and a quote.
Asking for a quote
There’s no need for technical detail. It helps if you can tell us:
- The type of property
- What the problem is, such as mould, gaps, leaks or cracking
- The address or postcode of the job
- A few pictures by email, if you can
We don’t publish a price list, because every job is different. Instead, your job gets its own clear quote. To get started, call 0345 464 0079 or email us.
What happens on the day
Before we leave, we go over the finished joints with you. The visit itself generally takes a few hours for a handful of frames, longer for a whole house, depending on the size of the job. Somewhere as small as Cumnor, access is often the only tricky part. For outside work, also let us know about exposed walls and any outbuildings involved.
- First, we confirm safe access to each frame.
- Old, cracked mastic is removed completely, along with any loose debris.
- Frame and wall are cleaned and must be dry before sealing, and primed where the sealant calls for it.
- Backing rod fills deep voids and the sealant goes in on top.
- We tool the joint so water runs off, then clear up.
Getting ready for the visit
- For indoor joints, keep the area dry beforehand if you can
- Let us know about parking restrictions
- Plan for the work area to be out of bounds to pets and children
Get a quote
It all starts with a short chat. Describe the problem, the location and the size of the job. Whenever you’re ready, call 0345 464 0079 or drop us an email.
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For landlords and businesses
From a single let to a portfolio, you get the same standard of work: the old material taken out, careful preparation and a 12-month guarantee.
A neglected joint can let water reach the structure, which matters even more when someone else lives there. Keeping joints in good order is simple maintenance that we can handle for you.
Looking after it afterwards
Looking after new joints is easy, and it makes a real difference:
- Use gentle cleaners on frames and sealant
- Keep timber frames painted
- Look round the frames every year or so
- Avoid harsh chemicals near the mastic
Silicone can’t usually be painted, so mention any painting plans before any work starts. There are paintable sealants for joints that need it.
Draughts get worse, not better. As old mastic keeps shrinking, the gap widens, and heat escapes around the frame. A new joint closes it up.
Common questions in Cumnor
Do you cover Cumnor for window mastic?
Yes, Cumnor is within the area we cover. Our work covers London and the South East. Just ring 0345 464 0079 or email us with a few details of the job, and we will send you a clear quote.
Will you come out to Cumnor?
Yes, smaller places are covered as well as towns. We work across London and the South East. Just mention lanes, gates or anything else about the route when you book.
What should I tell you?
The location, the problem and the rough size of the job. Photos by email help too.
Do you have insurance?
Yes. Mr Mastic is fully insured.
Do I need to be at home?
For indoor joints, yes, someone needs to let us in. Once we’ve agreed the job, you don’t need to watch us work.
When is the sealant fully cured?
Many sealants skin over quickly but take longer to cure fully. We’ll tell you how long to leave the joint.
Will resealing my frames help with draughts?
If the draught is coming in around the frame, yes. If it’s coming through the window seals, we’ll tell you.
Is it OK to seal over old sealant?
No. Fresh sealant doesn’t stick to old sealant, and anything trapped underneath, including mould and water, stays there. We remove it all first.
Cumnor homes and the weather
With historic houses such as Appleton Manor (about 1.9 miles south-west) nearby, there’s older building stock in the area around Cumnor as well as newer homes. In older buildings, older frames set in brick or stone need a sealant that suits them, and sometimes that is traditional sand mastic. The South East is one of the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
For landlords with property near Oxford station, sound mastic around windows and doors keeps out the draughts and damp that tenants notice first. In the older streets around Church of St Michael, the joint between an old wall and a newer frame is normally the first place rain gets in. Schools such as Cumnor Church of England School (Voluntary Controlled) are buildings too, and larger buildings have plenty of frames, and the mastic around each one ages.
Cumnor is about 4 miles north-west of Abingdon-on-Thames, in Oxfordshire. Cumnor gets the same service as everywhere we cover: the old material taken out, joints prepared properly and a 12-month guarantee. Our Oxfordshire coverage runs to 443 places, Cumnor among them.
Every address in OX2 is within our area for window mastic. Streets in the area include High Street, The Park and The Winnyards, all of which we cover. We also cover the places around Cumnor: Chawley (1 mile north-east), Filchampstead (1 mile north-west), Henwood (1 mile south-east), Dean Court (2 miles north-east) and Botley (2 miles north-east). Larger places within reach include Oxford (5 miles east), Didcot (9 miles south-east), Bicester (14 miles north-east), Abingdon-on-Thames (4 miles south-east), Witney (8 miles north-west) and Carterton (11 miles west).
Around Cumnor
Typical jobs here are in homes near The Vine Inn and Matthew Arnold School, among other places. The closest station to Cumnor is Oxford station, roughly 3.1 miles north-east. Other landmarks nearby include Westgate Shopping Centre (3.3 miles north-east) and Radcliffe Infirmary (3.6 miles north-east). For a walk, there’s Lashford Lane Fen and Cumnor Hill.
DIY versus a professional finish
A careful DIYer can reseal a simple joint, such as a straightforward joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
If you’ve already had a go yourself, that’s fine. We cut it out and start again, so just mention it when you contact us.
What the job involves on each surface
Aluminium frames
Large aluminium doors have long joints down each side and across the head, and the bottom joint sees the most water. We prepare and reseal every joint, backing the deep ones.
Window sills
Every drop off the glass ends up on the sill, so the sill ends and the joint under the frame are vital. Each is cleaned out and resealed.
Nearby places to Cumnor
More services for Cumnor
When something else is needed
In fairness, there are a few things sealant will not fix:
- Broken hinges, locks or handles
- Condensation trapped between the panes
- Rotten timber, which needs a joiner first
If in doubt, ring 0345 464 0079 or drop us an email and we will say what we think.
Where we work in Cumnor
- Patio & French doors
- Composite doors
- Timber windows & doors
- Aluminium frames
- uPVC windows
- Window sills