Kent · England
Window & door mastic in Seal, Kent
Window mastic for Seal, by sealant specialists with 20+ years’ experience. Rated 4.9 on Google from 180+ five-star reviews.
- Gaps between the frame and the inside reveal
- Rushed sealant from a window installation
- Cracked or shrunken mastic around the frame
Leave it or put it right?
Getting a straight, even bead on an outside frame takes practice, especially upstairs. We cut out properly, back deep gaps and tool every joint neatly, using a product chosen for the frame and wall. Older cottages and farmhouses around Seal can have timber floors and frames, where water from a failed joint can cause rot if it’s left.
The cost reflects the work involved, not guesswork. That is why we ask a few questions first and agree the price before starting.
What you get with us
- 4.9 on Google from 180+ five-star reviews
- Full insurance on every job
- White, clear, grey or another colour, product permitting
- We leave the area clean and tidy
Read what affects the cost and our reviews.
Window mastic for homes and businesses in Seal
Some gaps around frames are far deeper than they look. Filling it with sealant alone leaves a joint that cannot move properly, so we fit backing rod to set the right depth. That way the new bead bonds to the frame and the wall only. Common call-outs are for draughts coming in around windows and doors and rain getting in at the frame or under the sill, on patio & French doors, timber windows & doors and uPVC windows.
Around Seal, 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.
You get a 12-month guarantee, the same in Seal as everywhere else we work.
- Where
- Seal (TN15)
- Wider area
- Kent
- Cover
- A year, on every job
- Price
- A clear quote up front
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
How to look after the new joints
So the new joints stay in good condition:
- Wipe condensation off the frames
- Repaint timber before it’s bare
- Wash the frames with mild soapy water
- Avoid harsh chemicals near the mastic
Clean the frames with mild soapy water, and avoid solvent cleaners on the sealant.
Draughts get worse, not better. As old mastic keeps shrinking, the gap widens, and a cold room gets colder. A new joint closes it up.
Signs you need window mastic in Seal
Sills take more water than any other part of a window, so the sill ends and the joint below the frame are common leak points. When that sealant fails, water gets into the wall or under the frame.
Common reasons people contact us include:
- Leaking joints at the ends of sills
- Old mastic that has gone black or come away
- Gaps left after new windows were fitted
- Draughty joints inside around the window
In the older streets around Church of St Peter and St Paul, the windows may be timber, sash or later replacements, and each needs the right sealant against the wall.
What your quote should include
- Whether the sealant suits the joint
- What guarantee comes with the work
- Whether VAT is included
- When the joint can take water or movement
What window mastic looks like in Seal
The South East is one of the drier parts of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind. Historic houses like Knole House (about 1.8 miles south) are a reminder that the area around Seal has older buildings as well as new. In older buildings, older timber frames in brick or stone need a different approach from a modern uPVC window.
Schools such as Seal Church of England Voluntary Controlled Primary School are buildings too, and the mastic around its windows and doors needs looking after like any other building’s. Letting a property close to Bat & Ball station? Then renewing tired window mastic between tenants heads off draught and damp complaints.
Seal is about 2 miles north-east of Sevenoaks, in Kent. Homes, rented property, offices and hotels in Seal can book us for window mastic, old or new, large or small. The work is guaranteed for a year. Seal is one of 922 towns and villages in Kent we cover for window mastic. For nearby work, see our London page (20 miles or so).
Postcode districts we cover here for window mastic: TN15. Streets in the area include High Street, Church Road and Jubilee Rise, and we cover them all. If you’re just outside Seal, we cover Greatness (1 mile west), Godden Green (1 mile south), Styants Bottom (2 miles east), Stone Street (2 miles south-east) and Bitchet Green (2 miles south-east). Further out, we also cover Maidstone (13 miles east), Dartford (11 miles north), Royal Tunbridge Wells (11 miles south), Gravesend (12 miles north-east), Tonbridge (7 miles south) and Northfleet (11 miles north-east).
What’s near Seal
We work in homes and buildings around Wildernesse School, Kemsing Down and The Five Bells Public House and the streets around them. The closest station to Seal is Bat & Ball station, roughly 1.1 miles west of the centre. Well-known places in the area include Sevenoaks Hospital (1.1 miles west) and Sevenoaks Museum (1.7 miles south-west). For a walk, there’s Dryhill Nature Reserve.
Towns and villages near Seal
Also in Seal
Should I try it myself first?
Some sealant jobs are within reach of a careful DIYer, 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.
The difference is mostly in the preparation and the product. Joints are cleaned back to sound surfaces and dried, and the sealant is matched to the joint and its conditions, then guaranteed for a year.
What affects the quote in Seal
We don’t publish a price list, because no two jobs are the same. What we look at:
- Mould in or behind the old joints
- The old material and how stubborn it is
- Any working-time requirements on site
- The number of rooms or windows
Every job is a little different, so we quote each one individually. Size, access and the product the joint needs all make a difference.
What we need to know
What to tell us when you ask for a quote:
- The problem you’ve noticed
- The type of property
- How we’d reach the joints
- Any previous sealing or DIY work
Quotes start with a quick conversation. Tell us what’s wrong, where it is and how much there is, and we’ll talk you through what we’d do. When it suits you, phone 0345 464 0079 or send us an email.
What we do, step by step
We keep the work tidy and contained to the area we’re working on, so you can carry on as normal. The job normally takes most of a day for a typical house, less for a few frames, and we tell you how long to leave it before we go. In a small place like Seal, access is usually the main thing to plan. If the job is outside, mention outbuildings, exposed walls and how to reach them.
- First, we confirm safe access to each frame.
- Old, cracked mastic is removed completely.
- The surfaces are cleaned and left dry.
- Backing rod fills deep voids and the sealant goes in on top.
- The joint is shaped to shed water and the area tidied.
Preparing for the visit
- Mention any leaks or damp you’ve noticed
- Tell us if parking is tricky
- Move anything stored near the joints
Ask for a quote
There’s no standard price list, as no two jobs are quite the same. Instead, we give you a clear quote for your job. To arrange one, ring 0345 464 0079 or send us an email.
Advice
Seal: your questions answered
Can you help a landlord with a rental near Bat & Ball station?
Yes. We work for landlords and agents as well as householders, and several properties can go on one quote. Just ring 0345 464 0079 or send us an email with the address and what needs doing, and we’ll send you a clear quote.
Will you come out to Seal?
Yes. Seal is within the area we cover, which takes in towns, villages and rural addresses. Our work covers London and the South East. Let us know about access, parking and anything unusual about getting there when you book.
Can you quote for more than one area?
Yes. Tell us about everything you’d like done.
Do you do commercial work?
Yes, regularly. Larger jobs can be planned room by room or area by area to suit the site.
Where are you based?
We’re based in Crawley, and we cover South East England, London and all of Scotland.
Do I have to be there?
For indoor joints, yes, someone needs to let us in. After that, you can carry on with your day.
Can new window sealant be painted?
That depends on the product. Some hybrid sealants can be painted; silicone can’t. Mention any painting plans before we start.
Is it OK to seal over old sealant?
No. New silicone will not bond to old silicone, and anything trapped underneath, including mould and water, stays there. It all has to come out first.
When something else is needed
Sealant is not the answer to every problem, and we’d rather say so up front. It will not solve:
- A failed sealed unit that has misted up
- Broken hinges, locks or handles
- Draughts through the window seals rather than the frame
If in doubt, ring 0345 464 0079 or email us and we’ll say what we think before booking.
Where we work in Seal
- Window sills
- Composite doors
- Aluminium frames
- Timber windows & doors
- uPVC windows
- Patio & French doors