Greater London · England
Hither Green Window Mastic
Our applicators work in Hither Green on mastic around window and door frames, sills and patio doors. Old sealant removed completely, joints prepared properly and a 12-month guarantee.
- A bead that doesn’t match the frame
- Old mastic that has gone black or come away
- Draughts coming in around windows and doors
Window mastic in Hither Green, done properly
The new joint doesn’t have to be white. White, brown, anthracite grey, black and clear sealants are all available, so the bead blends with the window rather than framing it. We work on window sills, composite doors and uPVC windows, and people most often call us about mastic that has split away from the wall and untidy mastic left by window fitters.
London has a lot of flats and conversions, where windows are often on upper floors. Who looks after the outside of the frames can depend on the lease, so check that first, and access in Hither Green is something to talk through when you book.
The work is guaranteed for twelve months. If there’s a problem with our work within the year, let us know and we’ll sort it.
- Location
- Hither Green (SE13, SE12, SE6)
- Region
- Greater London
- Cover
- One year on every job
- Price
- A clear quote up front
- Call
- 0345 464 0079
- Updated
- 26 October 2026
When something else is needed
We’d rather tell you now than do work that will not last, so here’s what sealant can’t put right:
- Rotten timber, which needs a joiner first
- A door that needs adjusting, rehanging or new seals
- Condensation trapped between the panes
If you’re not sure, just phone 0345 464 0079 or drop us an email and we’ll give you a straight answer before you book.
What we seal
- uPVC windows
- Composite doors
- Window sills
- Patio & French doors
- Aluminium frames
- Timber windows & doors
Hither Green questions
Is Hither Green in your area for window mastic?
Yes, Hither Green is within the area we cover. Our work covers London and the South East. You can phone 0345 464 0079 or email us and let us know what needs doing, and we will give you a clear price.
Is parking a problem for a job in Hither Green?
London parking needs a little planning, so let us know about permits, bays or a driveway when you book. The visit is then planned around what’s available.
How do I get a quote for window mastic in Hither Green?
It depends on the job, so we quote each one individually. For a quick quote, phone 0345 464 0079 or drop us an email and let us know what needs doing and where.
What do you put in the joint?
It depends on the joint: sanitary silicone where it gets wet, and sealants suited to movement or weather elsewhere. We use products from Arbo and Everbuild.
Do you seal inside as well as outside?
Yes. Outside is the weather seal; inside closes the gap to the plaster. We can do either or both.
Is there any odour?
That depends on the sealant. Some products have a noticeable smell, others very little.
Do you guarantee window mastic?
Yes. Every job comes with our one-year guarantee, and we are fully insured.
Do you remove the old sealant?
Yes. All of the old material is cut out and the joint cleaned before applying anything new.
How it works
On the day, there’s very little for you to do. Point us to the joints and we will get on with it. The job generally takes a few hours for a handful of frames, longer for a whole house. Many London jobs are in flats, so we come ready for stairs, narrow hallways and shared entrances. Mention any building rules, key holders or managing agents when you book.
- First, we go round the frames with you and agree the list.
- The old mastic is cut out and scraped back to clean surfaces.
- Deep gaps get closed-cell backing rod to set the depth.
- The new sealant goes on in white, brown, anthracite grey, black or clear to suit.
- Every joint is tooled smooth and checked before we leave.
Preparing for the visit
- Mention any parking rules near the property
- On commercial sites, let us know about site rules
- Mention any leaks or damp you’ve noticed
Getting a quote
Call for a quick quote, or send an email if you’d rather. Describe what needs sealing and we will explain what’s involved before giving you a price.
Read more
What happens if it’s left?
Draughts and leaks do not always mean new windows. If the frames and glass are in good order, resealing the joints is often all that’s needed. Problems with the glass or gaskets are for a window company, and we’ll say so. In London conversions, one flat’s bathroom is often above another flat’s ceiling, and a slow leak from a failed seal can end up in the flat below. Putting it right early is much less trouble.
What it costs depends on the size of the job, how hard the old material is to remove and access to the work. You will have a clear quote before any work starts.
Why book with us
- 180+ five-star Google reviews
- Sealant colour chosen to suit
- A 12-month guarantee on all work
- 20+ years of sealant experience
See our cost guide or customer reviews.
Other services in Hither Green
What window mastic looks like in Hither Green
Historic houses like Queen's House (about 2 miles north) are a reminder that the area around Hither Green has older buildings as well as new. Where a home is older, older frames set in brick or stone need a sealant that suits them, and sometimes that is traditional sand mastic. In London conversions and blocks, the lease decides who is responsible for the frames, so it’s worth checking before booking.
In the older streets around Church of St Swithun, frames set in older brick or stone need a sealant that suits the wall as well as the frame. As a London address, Hither Green can be tricky for parking: tell us about permits, visitor bays or off-street space when you book.
Hither Green is about 2 miles south-east of New Cross, in Greater London. Wherever you are in the SE13 postcode area, we cover window mastic for homes and businesses. We cover 764 towns and villages across Greater London, large and small.
Our applicators cover all of the SE13, SE12 and SE6 postcode area for window mastic and the streets around it. We cover properties on Old Road, Manor Lane and Pascoe Road. We also cover the places around Hither Green: Lee (1 mile east), Ladywell (1 mile west), Lewisham (1 mile north-west), Catford (1 mile south-west) and Horn Park (1 mile east). Further out, we also cover London (5 miles north-west), City of Westminster (8 miles north-west), Marylebone (8 miles north-west), Kensington (9 miles west), St Pancras (7 miles north-west) and Shoreditch (6 miles north-west).
Local landmarks in Hither Green
In Hither Green, that means homes and buildings near International Academy of Greenwich, The Edmund Halley pub and Manor House Gardens, among other places. Hither Green has its own railway station: Hither Green station. A little further out are Lewisham Shopping Centre (0.9 miles north-west) and University Hospital Lewisham (0.7 miles west). Open spaces near Hither Green include Brookmill Road Local Nature Reserve and Summer Hill.
How we quote for window mastic
For a quick quote, just ask. What matters most is:
- The product the joint needs
- The number and length of the joints
- Whether the work is at height
- Whether there’s mould to deal with
Instead of a standard rate, we price the job in front of us: the amount of work, the old material and the access. You’ll know the price before we begin.
Helping us quote
To help us quote quickly, let us know:
- If it’s domestic, commercial or a hotel
- How many joints, rooms or windows are involved
- Access, such as stairs, a lift or height
- The problem you’ve noticed
Want a quote for window mastic? Please phone 0345 464 0079 or send us an email and tell us about the job. You’ll know what we plan to do, and what it will cost, before any work begins.
Aftercare tips
Good habits help new joints last longer. A few tips:
- Don’t paint over the silicone
- Keep jet washers away from the mastic
- Look round the frames every year or so
- Use gentle cleaners on frames and sealant
Try not to touch the new joint while it cures, following the cure time we give you. Do not point a pressure washer at the joints.
Draughts get worse, not better. As old mastic keeps shrinking, the gap widens, and heat escapes around the frame. Resealing closes it.
Different surfaces, different methods
uPVC windows
Some uPVC windows were sealed at fitting with a quick bead that never bonded. We cut it out, back any deep gaps and reseal properly.
Patio & French doors
Heavy door frames can move more than windows. A flexible sealant copes with that, where a rigid one would crack.
Common problems we fix in Hither Green
Older frames were often sealed with products that set hard. Once it’s rigid, every bit of frame movement pulls at it, leaving a hairline gap down one side.
It’s worth asking for a quote if you see:
- Hard, cracked sealant around windows
- Sealant in the wrong colour for the frame
- Water coming in at the bottom corners of a door
- Old mastic that has gone black or come away
Managing a site like Brindishe Manor School? Then its window and door frames need their mastic kept sound, just like a home’s.
Before booking anyone
- Who does the work, and how experienced they are
- Whether they seal over old material or remove it
- The length of the guarantee
- How the joint is cleaned and prepared