Slough · England
Longford Window Mastic
Our applicators work in Longford on mastic around window and door frames, sills and patio doors. Old material cut out, joints cleaned and sealed neatly and a one-year guarantee.
- White mastic on grey or black frames
- Black, perished sealant on frames
- Hard, cracked sealant around windows
How we handle window mastic in Longford
Behind a thin line of old mastic there’s sometimes a deep void. Filling it with sealant alone leaves a joint that cannot move properly, so deep gaps get backing rod first. The sealant then grips the two sides it should. If you’re dealing with draughty joints inside around the window and cracked sealant at the sill ends, we can help, on window sills, aluminium frames and uPVC windows alike.
Homes in small places like Longford often stand in the open, with little to shelter their windows from wind and rain. Exposed frames and sills lose their mastic sooner than sheltered ones.
Big or small, you get the same 12-month guarantee.
- Place
- Longford (SL3, UB7, TW6)
- Wider area
- Slough
- Cover
- A year, on every job
- Quotes
- Quoted before any work starts
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
How to look after the new joints
After the cure time, these simple habits help:
- Keep solvents and bleach off the sealant
- Keep paint off silicone joints
- Keep drainage slots and sill grooves clear
- Clean frames with a soft cloth and soapy water
Wipe the frames with soapy water when you clean the windows, and avoid solvent cleaners on the sealant.
A small gap around a frame only grows. As the old mastic shrinks further, more air gets through, and heat escapes around the frame. Resealing closes it.
Different surfaces, different methods
Patio & French doors
Door frames take knocks and movement every time the doors are used. A flexible sealant copes with that, where a rigid one would crack.
Window sills
Stone and concrete sills have their own joints, including the one between the sill and the frame above. Those are sealed with a product suited to stone or concrete.
DIY versus a professional finish
Sealing over old silicone is the commonest DIY error. New silicone won’t bond to old, so it peels away and traps moisture behind it. Everything old must be removed first.
A careful DIYer can reseal a simple joint, like a short, easy-to-reach joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
Frames and glazing around Longford
The South East is one of the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast. Historic houses like Frogmore House (about 4.3 miles west) are a reminder that the area around Longford 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.
Letting a property close to Heathrow Terminal 5 Rail station? Then cracked frame mastic tends to show up as a draught or damp complaint, so it’s worth checking between lets. Homes close to Church of St Mary include some older properties, and frames set in older brick or stone need a sealant that suits the wall as well as the frame. Schools such as Pippins School are buildings too, and the mastic around its windows and doors needs looking after like any other building’s.
Longford is about 2 miles south-west of West Drayton, in Slough. If you need window mastic in Longford, please ring 0345 464 0079 or email us for a quick quote. We cover Slough from our Crawley base, Longford included. Our Slough coverage runs to 31 places, Longford among them. There’s also a page for London, roughly 17 miles from Longford.
Jobs for window mastic in SL3, UB7 and TW6 is quoted and booked the same way as anywhere else. If you need window mastic at a property on Wallis Road, Widgeon Road and Stanwell Moor Road or anywhere close by, our applicators can take on the job. Being close to the A3044, Longford is simple for us to get to. If you are just outside Longford, we cover Harmondsworth (1 mile north-east), Stanwell (2 miles south-east), Heathrow (2 miles east), Sipson (2 miles north-east) and West Bedfont (2 miles south-east). We also work in nearby towns such as Slough (6 miles north-west), Cippenham (7 miles north-west), Chalvey (5 miles west), Britwell (7 miles north-west), Langley (3 miles north-west) and Upton (5 miles north-west).
What’s near Longford
Typical jobs here are in homes near The Kings Arms and Arthur Jacob Nature Reserve. For rail, the closest station is Heathrow Terminal 5 Rail station, about 0.5 miles south-east of the centre. Well-known places in the area include Windsor Castle (4.8 miles west) and Harlington (2.1 miles north-east). Not far away are Crane Meadows and Staines Reservoirs.
What we do, step by step
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 morning for a couple of windows and a door, including the tidy-up. Somewhere like Longford needs a little journey planning: tell us about narrow lanes, gates, long drives and where we can park. Everything for the job comes with us, so a second trip is avoided where possible.
- We start by checking each window and door with you.
- The old mastic is cut out and the surfaces cleaned back.
- Where gaps are deep, backing rod goes in first.
- A flexible, weatherproof sealant is applied in a colour to suit the frame.
- We clear up and check every joint is fully closed.
How to prepare
- Mention any sign-in or site rules at work premises
- Tell us about any previous sealing or DIY attempts
- Where the joints are inside, avoid wetting them before we arrive
Getting a quote
To get a quote, call 0345 464 0079 or drop us an email with the location and a short description of the problem. We will give you a clear price before any work starts.
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What we can’t put right
Some problems need a builder, plumber or other trade rather than us:
- A door that needs adjusting, rehanging or new seals
- Rotten timber, which needs a joiner first
- Misting between the panes of a double-glazed unit (that needs a new unit)
If in doubt, phone 0345 464 0079 or email us and we’ll say what we think before booking.
Surfaces we seal
- uPVC windows
- Aluminium frames
- Timber windows & doors
- Composite doors
- Window sills
- Patio & French doors
Longford questions
Do you cover Longford for window mastic?
Yes. Our work covers London and the South East, and Longford is part of that. You can ring 0345 464 0079 or drop us an email and let us know what needs doing, and we will give you a clear quote.
Do you work for landlords with property near Heathrow Terminal 5 Rail station?
Yes. We work for landlords and letting agents as well as homeowners. Just ring 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, we do both. Indoors, we seal between the frame and the plaster or reveal, using a paintable sealant if you want to decorate.
Do you have insurance?
Yes. We are fully insured, and we can confirm the details when we quote.
How do I get a quote for window mastic in Longford?
There’s no set price, as it depends on the job: how much there is, what’s there now, how we reach it and what it needs. We agree the price before any work begins.
Can you quote for more than one area?
Yes. More than one area can be quoted together.
When is the sealant fully cured?
Most sealants are touch-dry well before they’re fully cured. We’ll give you the cure time for the product we used.
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.
Towns and villages near Longford
Other services in Longford
Work for landlords, hotels and businesses
Failed sealant is one of the commonest items on a check-out report, and it’s easy to sort out between tenants. Several properties can go on one quote.
Letting agents often deal with us directly. Tell us the address, the job and how access works.
How we quote for window mastic
The quote reflects the job in front of us. We take into account:
- The type of sealant required
- Any mould that needs treating
- Any working-time requirements on site
- How easy the joints are to reach
The cost reflects the work involved, not a rough estimate. That is why we ask a few questions first and send you a clear quote before work begins.
Asking for a quote
What to tell us when you ask for a quote:
- The type of property
- What’s wrong with the joints now
- Any previous sealing or DIY work
- The address or postcode of the job
For a quick quote, get us on the phone, or email us if that is easier. Tell us about the joints that need doing and we’ll talk you through the work.