Greater London · England
Window & door mastic in Deptford, Greater London
Window and door frames in Deptford need attention? We cut out the old, prepare the joints and apply the right sealant, and the work is guaranteed for a year.
- Sealant in the wrong colour for the frame
- Cracked internal joints between frame and plaster
- Mastic that’s falling out in pieces
About our window mastic in Deptford
Some gaps around frames are far deeper than they look. Packing it solid with sealant gives a joint that can’t flex, so we fit backing rod to set the right depth. The sealant then grips the two sides it should. If you’re dealing with draughty joints inside around the window and sealant in the wrong colour for the frame, we can help, on timber windows & doors, uPVC windows and composite doors alike.
From mansion-block windows to modern glazing in new flats, London has every kind of frame. The mastic around them dries out and cracks with age, which is when draughts and damp patches appear in homes in Deptford.
Our work is backed for twelve months, and the guarantee is the same wherever you are.
- Place
- Deptford (SE8, SE10, SE14)
- Wider area
- Greater London
- Cover
- One year on every job
- Quote
- Quoted before any work starts
- Call
- 0345 464 0079
- Last updated
- 26 October 2026
What affects the cost of window mastic
Jobs vary more than people expect. The main factors:
- How easy the joints are to reach
- Any working-time requirements on site
- Whether there’s mould to deal with
- The old material and how stubborn it is
Leaving a failed joint generally makes the job bigger, not smaller, as water and mould keep getting in. If you are not sure whether it needs doing, ring 0345 464 0079 or send us an email and we will give you an honest view and a quote.
Asking for a quote
You do not need to know the technical terms. Just tell us:
- Pictures of the joints, sent by email
- Whether it has been sealed before
- Where the job is, and your postcode
- What’s wrong with the joints now
A good description makes for an accurate quote. Tell us where the job is, what’s wrong and how much there is.
Nearby places to Deptford
Also in Deptford
What we do, step by step
When we get to you, we compare the joints with what we discussed. If anything is different, we explain it before carrying on. After that, the work takes a few hours for a few frames, or a day or more for a whole house. Parking in much of London is by permit or pay-and-display, so it helps to know what’s near you in Deptford. A visitor permit or a nearby bay makes the visit run more smoothly.
- 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.
- The joint is shaped to shed water and the area tidied.
Before we arrive
- Keep children and pets away from the work area
- Try not to wet indoor joints just before the visit
- Let us know about earlier repairs to the joints
Getting a quote
Want a quote for window mastic? Please phone 0345 464 0079 or send us an email with a few details. You will know what we plan to do, and what it will cost, before any work begins.
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Deptford: your questions answered
Is Deptford in your area for window mastic?
Yes. We work across London and the South East, and Deptford is part of that. Just call 0345 464 0079 or email us with a few details of the job, and we will send you a clear quote.
Is parking an issue for window mastic in Deptford?
Parking in Deptford, as in most of London, takes a little planning: a visitor permit or a bay close to the door helps a lot.
Does the work come with a guarantee?
Yes. Each job is covered for 12 months.
Can you do upstairs windows?
Yes, where they can be reached safely. Tell us about access when you get in touch and we will plan for it.
Do you work for landlords and businesses?
Yes, we do. Domestic, commercial and hotel work are all part of what we do.
Can you seal the gap between the frame and the plaster indoors?
Yes. Indoors, we seal between the frame and the plaster or reveal, using a paintable sealant if you want to decorate.
Will there be a smell?
It depends on the product. Some smell for a while, some hardly at all, and any smell fades as they cure.
Will it make a mess?
We keep the work tidy. Nearby surfaces are protected, and we clear up when we are done.
How to look after the new joints
Once the sealant has cured, a few habits help it last:
- Keep paint off silicone joints
- Make sure the drainage slots aren’t blocked
- Air rooms to keep condensation down around windows
- Keep jet washers away from the mastic
Have a look at the joints once a year, ideally after winter. Cracks and lifting edges are easy to spot early, and if anything looks wrong, just phone 0345 464 0079 or drop us an email.
Leaks usually show up in wet, windy weather, but resealing works best in dry conditions. Sorting cracked mastic early means the joint is sound before the bad weather.
Signs you need window mastic in Deptford
Joints that are too thin or too deep fail early. A skim of sealant over a wide gap soon tears, and a gap filled solid cannot flex. That is what backing rod is for.
Look out for any of the following:
- Cracked internal joints between frame and plaster
- Whistling draughts around closed windows
- Sealant in the wrong colour for the frame
- Leaking joints at the ends of sills
For site and facilities teams at buildings such as Tidemill Academy, its window and door frames need their mastic kept sound, just like a home’s.
What your quote should include
- How much experience the applicator has
- What insurance they hold
- Whether VAT is included
- How the colour is chosen
DIY versus a professional finish
A DIY attempt doesn’t rule out a professional job. We cut it out and start again, so just mention it when you contact us.
The difference is mostly in the preparation and the product. We take joints back to clean, dry surfaces, and the sealant is matched to the joint and its conditions.
Windows and doors in Deptford
With historic houses such as Queen's House (about 1 mile east) nearby, there’s older building stock in the area around Deptford as well as newer homes. Where a home is older, older timber frames in brick or stone need a different approach from a modern uPVC window. In London conversions and blocks, the lease decides who is responsible for the frames, so check that before booking.
If you live in an older home near St. Paul's, the joint between an old wall and a newer frame is generally the first place rain gets in. Rented homes near Deptford station change hands often, and sound mastic around windows and doors keeps out the draughts and damp that tenants notice first.
Deptford is about 3 miles south-east of Whitechapel, in Greater London. For window mastic in and around Deptford, it’s easy to get a quote: please phone 0345 464 0079 or email us. We are based in Crawley and cover Greater London. 764 places in Greater London are on our list, large and small.
Every address in SE8, SE10 and SE14 is covered for window mastic. You will find streets such as Mill Lane, Dixon Road and Clare Road, and we cover them all. Deptford is on the A2209, which makes it straightforward to reach with everything needed for window mastic. If you’re just outside Deptford, we cover New Cross (1 mile south-west), St Johns (1 mile south), Millwall (1 mile north), Isle of Dogs (1 mile north-east) and North Greenwich (1 mile north-east). Larger places within reach include London (3 miles north-west), City of Westminster (6 miles north-west), Marylebone (6 miles north-west), Kensington (8 miles west), St Pancras (5 miles north-west) and Shoreditch (4 miles north-west).
Around Deptford
We work in homes and buildings around Addey and Stanhope School, Sue Godfrey Nature Park and Deptford Arms, among other places. There’s a railway station in Deptford itself: Deptford station. A little further out are Greenwich Castle (1.1 miles east) and Lewisham Shopping Centre (1.3 miles south-east). For a walk, there’s Sue Godfrey Nature Park and Tower Hill.
Different surfaces, different methods
Timber windows & doors
On period timber windows, traditional sand mastic is sometimes the better choice. We’ll tell you which suits your home.
Composite doors
A composite door generally sits in a plastic outer frame, so its perimeter joint is sealed much like a window. We match the colour to the frame.
Why it’s worth doing now in Deptford
Draughts and leaks don’t always mean new windows. Where the frames are sound, new mastic generally deals with draughts and leaks at the edges. If we find failed glass units or worn seals, we’ll tell you. In London conversions, one flat’s bathroom is often above another flat’s ceiling, so a small leak from tired sealant can mean a neighbour’s ceiling and a lot of disruption. Dealing with it early is far simpler.
Combining jobs into one visit normally makes better use of the time than several visits, so it’s worth mentioning everything you’d like done. You’ll get one clear quote for the whole job.
What you get with us
- ARBOMaster approved applicator
- Any old sealant cut out fully, not covered over
- 12-month guarantee on every job
- A sealant colour to suit the surroundings
Take a look at what affects the cost or customer reviews.