Greater London · England
Window & door mastic in Welling, Greater London
Mastic around window and door frames, sills and patio doors for householders, landlords and businesses in Welling. ARBOMaster approved applicators, fully insured, with a 12-month guarantee.
- Rushed sealant from a window installation
- Old mastic that has gone black or come away
- Hard, cracked sealant around windows
Window mastic for homes and businesses in Welling
Whether it’s one leaking patio door or every frame on the house, the work is priced before anything is done. Just ring 0345 464 0079 or drop us an email and tell us how many frames there are and how they’re reached for window mastic in Welling. We work on aluminium frames, uPVC windows and window sills, and common reasons people get in touch are draughts coming in around windows and doors and gaps between the frame and the inside reveal.
London homes have every kind of window, from timber sashes in period terraces to aluminium and uPVC in newer blocks. The mastic around them dries out and cracks with age, which is when draughts and damp patches appear in homes in Welling.
Big or small, you get the same 12-month guarantee in Welling and across Greater London.
- Where
- Welling (DA16, DA15, DA6)
- Region
- Greater London
- Guarantee
- 12 months on all our work
- Quotes
- A clear price before we start
- Call
- 0345 464 0079
- Updated
- 26 October 2026
Frames and glazing around Welling
Rainfall in the South East is lower than in much of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind. With historic houses such as Danson House (about 0.4 miles south-east) nearby, there’s older building stock in the area around Welling as well as newer homes. In older buildings, older timber frames in brick or stone need a different approach from a modern uPVC window.
For site and facilities teams at buildings such as Danson Primary School, its window and door frames need their mastic kept sound, just like a home’s. In the older streets around St John's Church, the joint between an old wall and a newer frame is normally the first place rain gets in.
Welling is about 9 miles east of London, in Greater London. Our applicators cover window mastic for homeowners, landlords and businesses in Welling, as part of our work across Greater London. Our area takes in 764 places across Greater London, large and small. You can also see our page for London, about 9 miles away.
All of DA16, DA15 and DA6 is covered for window mastic. If you need window mastic at a property on Days Lane, Hook Lane and Lyme Road or anywhere close by, our applicators can take on the job. Welling sits on or near the A207, which makes travel easy. Neighbouring places we cover for window mastic include Crook Log (1 mile east), Blendon (1 mile south-east), Upton (1 mile east), Bexleyheath (1 mile east) and West Heath (1 mile north-east). Further out, we also cover London (9 miles west), City of Westminster (12 miles west), Marylebone (12 miles west), Kensington (14 miles west), St Pancras (11 miles north-west) and Shoreditch (9 miles north-west).
Local landmarks in Welling
Locally, jobs take us to homes and businesses close to Nags Head pub, Danson Park and Bexley Grammar School, among other places. The nearest railway station is Welling station, about 0.5 miles north-west. Nearby you’ll also find Greenwich Castle (5 miles west) and Broadway Shopping Centre (1.6 miles east). Not far away are The Tarn and Summer Hill.
For landlords and businesses
In hotels, rooms out of use cost money, so the work can be planned room by room. Hotel work is part of what we do, alongside homes and businesses.
If you manage several properties in or around Welling, several properties can be quoted together. Just tell us the addresses and what each one needs, and photos by email help.
When to call us in Welling
Plenty of failed mastic was poorly applied in the first place. Sealant run over dust, wet brick or loose mortar didn’t grip properly, and it lets go sooner than it should.
It’s worth asking for a quote if you see:
- Gaps between the frame and the inside reveal
- Whistling draughts around closed windows
- Damp patches on the reveal after heavy rain
- Old mastic that has gone black or come away
Rented homes near Welling station change hands often, and renewing tired window mastic between tenants heads off draught and damp complaints.
What your quote should include
- What the quote includes, VAT included or not
- Whether they seal over old material or remove it
- What insurance they hold
- What happens if they find a problem under the old sealant
Nearby places to Welling
What else we do in Welling
What sealant work cannot fix
Before you book, it’s worth knowing the limits too:
- Misting between the panes of a double-glazed unit (that needs a new unit)
- A sash or casement that will not close properly
- Worn gaskets, brush seals or a door that has dropped
Not sure which it is? You can ring 0345 464 0079 or email us and we will tell you honestly.
Joints and surfaces we work on
- Window sills
- uPVC windows
- Aluminium frames
- Patio & French doors
- Timber windows & doors
- Composite doors
What happens if it’s left?
Getting a straight, even bead on an outside frame takes practice, especially on upper floors. A professional job is cut out properly, backed where needed and finished neatly, in a sealant suited to the wall. Converted houses in London often have a bathroom above someone else’s living room, 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.
We do not show prices on the website, because the cost depends so much on the job itself. For a quick quote, please ring 0345 464 0079 or email us.
Why choose Mr Mastic in Welling
- More than 20 years in sealant work
- Fully insured
- Experience in homes, commercial sites and hotels
- Rated 4.9 stars on Google
See our cost guide or customer reviews.
Common questions in Welling
Can you do window mastic in Welling?
Yes, Welling is within the area we cover. We work across London and the South East. You can phone 0345 464 0079 or drop us an email and tell us what needs doing.
Do you work for landlords with property near Welling station?
Yes, landlords and agents are among the people we work for, and several properties can be quoted together. Just phone 0345 464 0079 or send us an email with the address and what needs doing, and we will send you a clear quote.
Can you do the inside joint as well?
Yes. Outside is the weather seal; inside closes the gap to the plaster. We can do either or both.
Does the work come with a guarantee?
Yes, for 12 months. A yearly look at the joints helps them last.
Do you work for hotels and businesses?
Yes. Hotels, offices and other businesses use us and we’re fully insured.
Will there be a smell?
Some sealants have a smell while they cure, but it fades. Opening a window helps.
Can I add another job to the visit?
Yes. Just list everything you need and we will quote it together.
How many windows can you do in a day?
That depends on the number of frames, how they’re reached and the state of the old mastic. We will tell you how long your job needs when we quote.
How the job changes by surface
Composite doors
Composite doors are normally hung in an uPVC-type frame, so its perimeter joint is sealed much like a window. The bead is colour-matched to the frame.
Patio & French doors
Door frames take knocks and movement every time the doors are used. A flexible sealant copes with that without cracking.
How to look after the new joints
Once the sealant has cured, a few habits help it last:
- Look round the frames every year or so
- Don’t paint over the silicone
- Keep paint and stain on wooden frames in good order
- Clean frames with a soft cloth and soapy water
Try not to touch the new joint while it cures, for as long as we advise. Do not point a pressure washer at the joints.
Leaks normally 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.
What we do, step by step
We keep the work tidy and contained to the area we are working on, so you can get on with your day. Expect the work to take a few hours for a few frames, or a day or more for a whole house, and we tell you how long to leave it before we go. In Welling, flats, stairs and shared entrances are part of the routine. Mention any building rules, key holders or managing agents when you book.
- First, we confirm safe access to each frame.
- Old, cracked mastic is removed completely, along with any loose debris.
- The surfaces are cleaned and left dry, 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.
How to prepare
- Tell us about access, such as stairs, a lift or high-level joints
- Mention any sign-in or site rules at work premises
- Let us know about parking restrictions
Get a quote
For a quote, call 0345 464 0079 or email us and tell us where the job is and what the problem looks like. We’ll give you a clear price before any work starts.