Kent · England
Window & door mastic in Cobham, Kent
Our applicators work in Cobham on mastic around window and door frames, sills and patio doors. Old sealant removed completely, joints prepared properly and every job guaranteed for a year.
- Mastic that’s falling out in pieces
- White mastic on grey or black frames
- Cold air getting in at the frame edge
What we are called out for in Cobham
Timber windows bring their own problems. Old mastic gets painted over and cracks under the paint, and timber moves with moisture as well as temperature.
It’s worth asking for a quote if you see:
- Draughty joints inside around the window
- Sealant in the wrong colour for the frame
- Leaking joints at the ends of sills
- Whistling draughts around closed windows
For landlords with property near Sole Street station, renewing tired window mastic between tenants heads off draught and damp complaints.
Questions to ask before you book
- How long to leave it before use
- Is the old sealant removed completely?
- How the surfaces are prepared before sealing
- What happens if the job turns out different
Window mastic in Cobham, done properly
Every window and door frame has a gap around it, and mastic is what closes it. When it cracks, hardens or pulls away, draughts and rain get in. The old mastic is removed and the joint resealed with a flexible exterior sealant. We work on aluminium frames, composite doors and patio & French doors, and common reasons people get in touch are rain getting in at the frame or under the sill and gaps where the sill meets the wall.
Mastic can only go onto a dry, clean joint, so window work in Cobham is booked around the forecast. Let us know about access to all the frames, upstairs ones included.
We stand behind the work with a one-year guarantee.
- Where
- Cobham (DA12)
- Region
- Kent
- Cover
- One year on every job
- Price
- A clear price before we start
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
How to look after the new joints
A little care helps the new joints last. Our advice:
- Clean frames with a soft cloth and soapy water
- Repaint timber before it’s bare
- Keep jet washers away from the mastic
- Make sure the drainage slots are not blocked
Keep the new mastic undisturbed while it cures, following the cure time we give you. Keep jet washers away from the frames.
On timber windows, water behind the joint can lead to rot. Once wood has rotted, it needs repair before it can be sealed, so early resealing is worth it.
For landlords and businesses
A neglected joint can let water reach the structure, which matters even more when someone else lives there. Resealing at the right time is simple maintenance that we can handle for you.
Businesses can book us for washrooms, kitchens, offices and more. For commercial premises, we can talk through working times when we quote.
Window mastic in Cobham: local notes
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. Historic houses like Cobham College (about 0.2 miles south-west) are a reminder that the area around Cobham has older buildings as well as new. Where a home is older, older timber frames in brick or stone need a different approach from a modern uPVC window.
Schools such as Cobham Primary School are buildings too, and larger buildings have plenty of frames, and the mastic around each one ages. For an older house near a landmark such as Parish Church of St Mary Magdalene, the windows may be timber, sash or later replacements, and each needs the right sealant against the wall.
Cobham is about 3 miles south of Gravesend, in Kent. From the centre of Cobham to the outskirts, window mastic is available for homes and businesses alike. Cobham is one of 922 towns and villages in Kent where we work. Our London page covers work nearby, about 23 miles away.
All of DA12 is within our area for window mastic, from the main roads to the quietest streets. You will find streets such as The Street, Lawrence Drive and Cobhambury Road, all of which we cover. We also cover Upper Bush (2 miles south-east), Lower Bush (2 miles south-east), Cuxton (2 miles south-east), North Halling (3 miles south-east) and Upper Halling (3 miles south). Within a short drive, we also cover Maidstone (10 miles south-east), Sittingbourne (15 miles east), Dartford (8 miles north-west), Sevenoaks (12 miles south-west), Gravesend (3 miles north) and Tonbridge (14 miles south).
What’s near Cobham
Around Cobham, our work takes us to homes and buildings near Thamesview School, The Ship Inn and Jeskyns. Cobham’s nearest station is Sole Street station, about 1.2 miles south-west of the centre. A little further out are Rochester Castle (4.3 miles east) and Gravesham Community Hospital (3.9 miles north-west). Not far away are Gad's Hill and Ranscombe Farm.
How it works
There’s no need to move everything out before we come, only the area right around the joints. We protect the rest, and the job takes a few hours for a few frames, or a day or more for a whole house in most cases. For a village or hamlet like Cobham, the journey is planned in advance: let us know about lanes, gates and parking. We bring what the job needs, so it can be finished in one trip where possible.
- We check each frame and agree which ones need doing.
- We remove the old mastic and clean the frame and the wall.
- We fit backing rod in deep gaps so the sealant is the right depth.
- We apply a weatherproof sealant to match the frame and tool it neatly.
- We clear up and check every joint is fully closed.
Getting ready for the visit
- Tell us about access, such as stairs, a lift or high-level joints
- Keep pets and children clear of the area while we work
- Mention if the joints have been sealed before
How to get a quote
For a quote, ring 0345 464 0079 or drop us an email with the location and a short description of the problem. You will have a clear quote before we start.
Related advice
Surface by surface
Window sills
The end joints of a sill tend to fail before the rest. A tight seal at each end keeps rain out of the wall.
Timber windows & doors
Where timber has rotted at the joint, it needs repairing first. We will point out any rot we find, as that’s a job for a joiner.
Places near Cobham
More services for Cobham
Cobham: your questions answered
I let a flat near Sole Street station. Can you help?
Yes, rental work is part of what we do. Just ring 0345 464 0079 or drop us an email and tell us about the property, and we will give you a clear quote.
Is Cobham in your area for window mastic?
Yes, Cobham is within the area we cover. We work across London and the South East. Just ring 0345 464 0079 or email us with a few details of the job, and we’ll give you a clear price.
Can I paint over the new sealant?
Not generally, if it’s silicone. Tell us your decorating plans and we will pick a sealant to suit.
Can I add another job to the visit?
Yes, we can. Several rooms, windows or areas can go on one quote.
What does window mastic cost?
There’s no set price, as it depends on the job: its size, the old material, access and the product needed. We agree the price before any work begins.
Will there be a smell?
Some sealants have a smell while they cure, but it fades. Opening a window helps.
Where do you work from?
We are based in Crawley, and we work across South East England, London and Scotland.
Can you do the inside joint as well?
Yes. Draughts often come through the inside gap too, so it can be worth sealing both.
Should I try it myself first?
If you do try it yourself, take your time over the 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.
Too much sealant is as bad as too little. A thick, smeared bead looks untidy and doesn’t move well, and the joint depth matters as much as the finish.
What affects the cost of window mastic
Jobs vary more than people expect. What affects the quote:
- The number of rooms or windows
- Any mould that needs treating
- When we can work, for business premises
- The type of sealant required
The cost reflects the work involved, not guesswork. That’s why we ask a few questions first and send you a clear quote before we start.
What we need to know
The more you tell us, the more accurate the quote. When you get in contact, it helps to mention:
- What the problem is, such as mould, gaps, leaks or cracking
- How many joints, rooms or windows are involved
- Access, such as stairs, a lift or height
- Any previous sealing or DIY work
Getting a quote is simple: let us know what needs doing and where. Photos by email help us understand the job, and we will come back to you with a quote.