Greater London · England
Park Royal Window Mastic
Mastic around window and door frames, sills and patio doors for Park Royal, backed by a one-year guarantee. Call for a quick quote.
- Mastic that is falling out in pieces
- Draughty joints inside around the window
- Untidy mastic left by window fitters
Window mastic in Park Royal
Every window and door frame has a gap around it, and mastic is what closes it. Once that seal fails, wind and rain find the gap. Our applicators cut it out and replace it with a flexible, weatherproof sealant. If you’re dealing with rushed sealant from a window installation and hard, cracked sealant around windows, we can put it right, on composite doors, window sills and timber windows & doors alike.
Many London homes are flats, with windows high above the street. In a converted house or block, the lease usually says who is responsible for the windows, so it’s worth checking before booking.
The work is covered for a year after we finish. If there’s a problem with it, please call 0345 464 0079 or email us.
- Where
- Park Royal (NW10, W3, W5)
- Region
- Greater London
- Guarantee
- A year, on every job
- Price
- Quoted before any work starts
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
How it works
Good joint work is mostly preparation, so that is where we spend the time. Every joint is cleaned and dried before new material goes in. In total, it normally takes most of a day for a typical house, less for a few frames. For a job in Park Royal, parking and access are the things to plan: let us know about parking, the floor we’ll be working on and any lift or shared entrance.
- We start by checking each window and door with you.
- We remove the old mastic and clean the frame and the wall.
- Where gaps are deep, backing rod goes in first.
- We apply a weatherproof sealant to match the frame and tool it neatly.
- Finally we tidy up and check each joint.
How to prepare
- Tell us about any previous sealing or DIY attempts
- On commercial sites, let us know about site rules
- Clear items away from the joints we’re working on
How to get a quote
For a quote, phone 0345 464 0079 or drop us an email with the location and a short description of the problem. You’ll have a clear quote before any work starts.
Advice
Questions from Park Royal
I let a flat near Harlesden station. Can you help?
Yes, rental work is part of what we do. Just call 0345 464 0079 or send us an email and tell us about the property, and we will give you a clear quote.
Can parking be tricky for a visit in Park Royal?
Parking in Park Royal, as in most of London, takes a little planning: a visitor permit or a bay close to the door helps a lot.
Are you ARBOMaster approved?
Yes. We hold ARBOMaster approved applicator status, and we are fully insured.
How much does window mastic cost in Park Royal?
It depends on the job, so we quote each one individually. To get one, phone 0345 464 0079 or drop us an email and let us know what needs doing and where.
Is there any odour?
That depends on the sealant. Some smell for a while, some hardly at all, and any smell fades as they cure.
Can you seal over the old sealant?
No, and we never do. It can look neat for a few weeks, but the new bead soon lifts. Removing the old sealant completely is the only lasting way.
Is the work guaranteed?
Yes. Every job comes with our one-year guarantee, and we’re fully insured.
Do I have to be there?
It depends on the job. Inside work needs someone to give us access, while outside work can sometimes be arranged differently.
What affects the quote in Park Royal
Every job gets its own quote. These are the things that affect it:
- How much old sealant there is and how hard it is to remove
- The type of sealant required
- Access and height
- The size of the job
Instead of a standard rate, we look at what your job involves: the amount of work, the old material and the access. The price is agreed before we begin.
Asking for a quote
When you call or email, it’s useful to know:
- The type of property
- Access, such as stairs, a lift or height
- Where the job is, and your postcode
- Photos by email, if that’s easy
Quotes start with a quick conversation. Describe the problem, the location and the size of the job, and we’ll talk you through what we’d do. Whenever you are ready, phone 0345 464 0079 or email us.
What happens if it’s left?
Getting a straight, even bead on an outside frame takes practice, especially upstairs. We cut out properly, back deep gaps and tool every joint neatly, using a product chosen for the frame and wall. In older London homes, water behind a failed joint soaks into brick and timber without much sign, and by the time it shows on a wall or ceiling in Park Royal, the repair is bigger than the sealant job would have been.
What it costs depends on how much there is to do, how hard the old material is to remove and how easy the joints are to reach. We give a clear quote before we start.
Why book with us
- 20+ years of sealant experience
- Experience in homes, commercial sites and hotels
- Old sealant always removed completely
- 180+ five-star Google reviews
Take a look at what affects the cost and our reviews.
Common problems we fix in Park Royal
Sills take more water than any other part of a window, and the ends of the sill, where it meets the wall, are where it gets in. When that sealant fails, water gets into the wall or under the frame.
Look out for any of the following:
- Rain getting in at the frame or under the sill
- Old mastic that has gone black or come away
- Gaps where the sill meets the wall
- Untidy mastic left by window fitters
Homes close to St Gabriel's Church include some older properties, and the windows may be timber, sash or later replacements, and each needs the right sealant against the wall.
What to look for in a quote
- Which sealant they’ll use, and why
- Whether VAT is included
- Whether they seal over old material or remove it
- Whether they’re fully insured
Frames and glazing around Park Royal
The South East is one of the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day. In London conversions and blocks, the lease decides who is responsible for the frames, so it’s worth checking before booking.
Park Royal is in London, so parking needs planning: let us know about parking bays, permits or a driveway. For site and facilities teams at buildings such as West Twyford Primary School, larger buildings have plenty of frames, and the mastic around each one ages.
Park Royal is about 1 mile south-west of Harlesden, in Greater London. Jobs in Park Royal get the same care as everywhere else we work: old sealant removed completely, careful preparation and a one-year guarantee. Park Royal is one of 764 towns and villages in Greater London we cover for window mastic. You can also see our page for London, roughly 8 miles from Park Royal.
Jobs for window mastic in NW10, W3 and W5 is quoted and booked the same way as anywhere else. If you need window mastic at a property on Dukes Road, Abbey Road and Grieg Road or a nearby road, we can help. We also cover the places around Park Royal: West Twyford (1 mile north-west), Hanger Hill (1 mile south-west), Stonebridge (1 mile north), Stonebridge Park (1 mile north) and Old Oak Common (1 mile east). We also work in nearby towns such as London (8 miles east), City of Westminster (5 miles east), Marylebone (5 miles east), Kensington (4 miles south-east), St Pancras (7 miles east) and Shoreditch (8 miles east).
Near you in Park Royal
In Park Royal, that means homes and buildings near St. Raphael's Edible Garden, Grand Junction Arms and The Ellen Wilkinson School for Girls. Nearby too are Library for Iranian Studies (1.5 miles south) and The Ellen Wilkinson School for Girls (1.1 miles south-west). For rail, the closest station is Harlesden station, about 0.8 miles north-east of the centre. Other landmarks nearby include London Designer Outlet (2 miles north) and London Transport Museum Depot (1.7 miles south). The countryside around Park Royal includes Castlebar Hill and Kew Gardens Lake.
Nearby places to Park Royal
What else we do in Park Royal
Keeping the joints in good condition
Simple care keeps the joints in good condition. We recommend:
- Ventilate rooms so frames don’t stay wet inside
- Don’t aim a pressure washer at the joints
- Wash the frames with mild soapy water
- Walk round the house once a year and look at the joints
Most silicone sealants will not take paint, so mention any painting plans before we start. We can use a paintable sealant where that matters.
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.
Can I do it myself?
The biggest DIY mistake is sealing over old sealant. New silicone won’t bond to old, so it peels away and traps moisture behind it. All the old material has to come out first.
Some sealant jobs are within reach of a careful DIYer, 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.
When it isn’t the sealant
New sealant cannot fix everything, and we’ll tell you before work begins. Sealant will not put right:
- Broken hinges, locks or handles
- A door that needs adjusting, rehanging or new seals
- Soft or decayed wood in the frame
Not sure which it is? You can phone 0345 464 0079 or send us an email and we will tell you honestly.
What we seal
- Patio & French doors
- Window sills
- uPVC windows
- Composite doors
- Aluminium frames
- Timber windows & doors