Greater London · England
Window Mastic in Dormers Wells
Mastic around window and door frames, sills and patio doors for homes and businesses in Dormers Wells and across Greater London. ARBOMaster approved applicators, fully insured, with a one-year guarantee.
- Untidy mastic left by window fitters
- Cracked internal joints between frame and plaster
- Old mastic that has gone black or come away
Window mastic in Dormers Wells
Over two decades of sealing frames has taught us which products suit which walls. We are fully insured ARBOMaster approved applicators, and every job is covered by a 12-month guarantee. Typical jobs include gaps between the frame and the inside reveal and whistling draughts around closed windows, across aluminium frames, timber windows & doors and window sills.
London has a lot of flats and conversions, where windows are often on upper floors. In a converted house or block, the lease normally says who is responsible for the windows, so it’s worth checking before booking, and access in Dormers Wells is something to talk through when you book.
Whatever the size of the job, you get the same 12-month guarantee.
- Place
- Dormers Wells (UB1, UB6, UB2)
- Region
- Greater London
- Cover
- A year, on every job
- Quote
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
What the job involves on each surface
Window sills
Every drop off the glass ends up on the sill, so the sill ends and the joint under the frame are vital. They’re cut out and resealed with exterior sealant.
Composite doors
If the door itself is draughty, the issue may be the door seals or hinges rather than the frame mastic. We will tell you if that is what we find.
Landlords, agents and businesses in Dormers Wells
We regularly work with letting and managing agents. Tell us the address, the job and how access works and we will give you a quote.
If you manage several properties in or around Dormers Wells, several properties can go on one quote. Send us the addresses and the work at each, and pictures by email help.
DIY sealant or a professional job?
If you’re set on DIY, put the effort into preparation: remove every trace of old sealant, clean and dry the joint, and follow the product’s cure time. If it fails, we can still redo it.
A careful DIYer can reseal a simple joint, 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.
Keeping the joints in good condition
So the new joints stay in good condition:
- Clear any debris from frame drain holes
- Do not paint over the silicone
- Ventilate rooms so frames don’t stay wet inside
- Repaint timber before it’s bare
Try not to touch the new joint while it cures, following the cure time we give you. Keep jet washers away from the frames.
Water trapped behind a failed joint can start rot in timber frames and sills. Rotten timber needs a joiner, not a sealant, so early resealing is worth it.
Also in Dormers Wells
Common problems we fix in Dormers Wells
Frames are never completely still. Sun on a frame makes it expand, and it contracts again overnight, while the brick or render around it hardly moves. If the sealant can’t stretch, it splits.
If you can see any of these, it’s time to have the joints looked at:
- Cracked sealant at the sill ends
- Damp patches on the reveal after heavy rain
- Sealant in the wrong colour for the frame
- Gaps between the frame and the inside reveal
Dormers Wells is in London, so parking needs planning: let us know about parking bays, permits or a driveway.
Comparing quotes
- Whether all the old sealant comes out first
- What preparation is included
- What happens if the job turns out different
- Whether they’re fully insured
What happens on the day
Most of a good job is in the preparation, so that’s where we spend the time. Joints are cleaned back and dried before anything new goes in. In total, it usually takes anything from an hour or two to a full day, depending on how many frames there are. Parking in much of London is by permit or pay-and-display, so it helps to know what’s near you in Dormers Wells. A visitor permit or a nearby bay makes the visit run more smoothly.
- First, we go round the frames with you and agree the list.
- We remove the old mastic and clean the frame edge and wall.
- 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.
How to prepare
- Tell us if parking is tricky
- Tell us about any previous sealing or DIY attempts
- Mention any tricky access
How to get a quote
It all starts with a short chat. 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, call 0345 464 0079 or drop us an email.
Related advice
Common questions in Dormers Wells
Can you do window mastic in Dormers Wells?
Yes. Our work covers London and the South East, and Dormers Wells is part of that. You can call 0345 464 0079 or drop us an email and tell us what needs doing.
Is parking a problem for a job in Dormers Wells?
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.
I’m a tenant. Can you help?
Yes, though it’s best to check with your landlord first. Landlords are often happy for the work to be arranged.
Where is Mr Mastic based?
We’re based in Crawley, West Sussex, and we cover South East England, London and all of Scotland.
Can I add another job to the visit?
Yes, and it often makes sense. Doing several areas at once is normally more efficient, so mention them when you ask for a quote.
Do the sealants smell?
It depends on the product. Some products have a noticeable smell, others very little.
Do you remove the old sealant?
Yes. All of the old material is cut out and the joint cleaned before applying anything new.
Can you do the inside joint as well?
Yes. Outside is the weather seal; inside closes the gap to the plaster. We do one or both.
What window mastic looks like in Dormers Wells
In a converted house or block, who looks after the windows depends on the lease, so it’s worth checking before booking. London and the South East are among the drier parts of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
For an older house near a landmark such as Emmanuel Church, the windows may be timber, sash or later replacements, and each needs the right sealant against the wall. If you look after a building such as Dormers Wells Junior School, larger buildings have plenty of frames, and the mastic around each one ages.
Dormers Wells is about 1 mile north-east of Southall, in Greater London. From the centre of Dormers Wells to the outskirts, we cover window mastic for every kind of property. 764 places in Greater London are on our list, from the larger towns to small villages. Our London page covers work nearby, about 12 miles away.
Jobs for window mastic in UB1, UB6 and UB2 works the same way as everywhere else we cover. Whether your property is on Swan Road, North Road and Meadow Road or anywhere close by, our applicators can take on the job. Dormers Wells sits on or near the A4020. If you are just outside Dormers Wells, we cover Southall (1 mile south-west), West Ealing (1 mile south-east), Hanwell (1 mile south-east), Yeading (2 miles north-west) and Yiewsley (2 miles north-west). We also work in nearby towns such as London (12 miles east), City of Westminster (9 miles east), Marylebone (9 miles east), Kensington (7 miles east), St Pancras (11 miles east) and Shoreditch (12 miles east).
Around Dormers Wells
In Dormers Wells, that means homes and buildings near Dormers Wells High School, The Plough pub and Castle Bar Park. The nearest railway station is Southall station, roughly 0.9 miles south-west. Nearby you will also find St Bernard's Hospital (0.9 miles south-east) and Gunnersbury Park House - Large Mansion (3.5 miles east). Open spaces near Dormers Wells include Northala Fields and Litten Nature Reserve.
What sealant work cannot fix
A few problems are outside what sealant work can do:
- Misting between the panes of a double-glazed unit (that needs a new unit)
- A frame that has rotted at the joint
- Worn gaskets, brush seals or a door that has dropped
Not sure which it is? You can call 0345 464 0079 or send us an email and we will tell you honestly.
Surfaces we seal
- Timber windows & doors
- Window sills
- uPVC windows
- Aluminium frames
- Composite doors
- Patio & French doors