Kent · England
Window Mastic in Grubb Street
We cover Grubb Street for mastic around window and door frames, sills and patio doors. Old sealant removed completely, joints prepared properly and a one-year guarantee.
- Water coming in at the bottom corners of a door
- Cracked internal joints between frame and plaster
- Cold air getting in at the frame edge
About our window mastic in Grubb Street
Around Grubb Street we seal all kinds of frames: uPVC, aluminium, timber and composite, plus patio doors, French doors and sills. The sealant is chosen to suit the frame material and the wall. We work on composite doors, window sills and timber windows & doors, and common reasons people get in touch are gaps left after new windows were fitted and cold air getting in at the frame edge.
Outdoor sealant needs dry, clean surfaces, so work on frames around Grubb Street is planned for dry weather. Tell us about access to every side of the house, including upper-floor windows.
All our work is covered by a one-year guarantee.
- Location
- Grubb Street (DA2)
- Wider area
- Kent
- Guarantee
- 12 months on all our work
- Quotes
- A clear price before work begins
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
What sealant work can’t fix
Sealant isn’t the answer to every problem, and we’d rather say so up front. Sealant will not put right:
- Broken hinges, locks or handles
- Penetrating damp from a failed cavity tray or render
- A door that needs adjusting, rehanging or new seals
If in doubt, phone 0345 464 0079 or email us and we’ll say what we think.
What we seal
- uPVC windows
- Composite doors
- Window sills
- Patio & French doors
- Aluminium frames
- Timber windows & doors
Your questions about window mastic in Grubb Street
Will you come out to Grubb Street?
Yes, smaller places are covered as well as towns. We work across London and the South East. Let us know about access, parking and anything unusual about getting there when you book.
Is Grubb Street in your area for window mastic?
Yes. Our work covers London and the South East, and Grubb Street is part of that. Just call 0345 464 0079 or send us an email with a few details of the job.
What should I tell you?
A short description and the location, with photos by email if possible. If we need more, we’ll ask.
How many windows can you do in a day?
The work takes most of a day for a typical house, less for a few frames. Access and how stubborn the old mastic is affect the time most.
Do you have sealant for grey or black windows?
Yes. Grey and black frames get grey or black sealant, and wood-effect frames usually suit brown.
Does someone need to be in?
That depends on where the joints are. For work indoors, someone needs to let us in, and for outside work we will agree access with you when we book.
Where is Mr Mastic based?
Our base is in Crawley, West Sussex, and we work across South East England, London and Scotland.
Do you have insurance?
Yes. We’re fully insured.
Keeping the joints in good condition
Aftercare is simple, and it makes a real difference:
- Keep timber frames painted
- Do not aim a pressure washer at the joints
- Check the mastic once a year
- Clear any debris from frame drain holes
Silicone cannot usually be painted, so mention any painting plans before we start. There are paintable sealants for joints that need it.
A failed joint lets water into the wall a little at a time. You might not see it until plaster blows or a damp patch appears inside. Early resealing stops it reaching that point.
What we’re called out for in Grubb Street
Mastic ages in the weather. Sunlight dries the surface out, and over the years it loses its give, cracks and comes away.
The problems people generally mention when they call include:
- Cracked sealant at the sill ends
- Old mastic that has gone black or come away
- Water coming in at the bottom corners of a door
- A bead that does not match the frame
Schools such as Greenlands Primary School are buildings too, and larger buildings have plenty of frames, and the mastic around each one ages.
What to look for in a quote
- How much experience the applicator has
- How the surfaces are prepared before sealing
- How hidden problems are handled
- Which sealant they’ll use, and why
Surface by surface
Timber windows & doors
Timber moves with moisture as well as heat, so the joint must stay flexible. We seal onto sound, dry paintwork or timber.
Composite doors
Front doors take the weather head on. We pay most attention there.
Quotes for window mastic in Grubb Street
For a quick quote, just ask. The main things that affect it are:
- Any mould that needs treating
- The amount of work
- Whether the work is at height
- Whether old sealant or filler has to be cut out
A failed joint rarely gets cheaper to fix by waiting, because water and mould keep working on it. If you are not sure whether it needs doing, call 0345 464 0079 or drop us an email for an honest opinion and a quote.
What to tell us for a quote
What to tell us when you ask for a quote:
- The problem you’ve noticed
- Whether it’s a home or a business
- Where the job is, and your postcode
- The rough size of the job
A good description makes for an accurate quote. Let us know the location, the problem and roughly how many joints, and email photos if that is easy.
Grubb Street homes and the weather
Historic houses like Lullingstone Castle (about 5 miles south-west) are a reminder that the area around Grubb Street has older buildings as well as new. In older buildings, older frames set in brick or stone need a sealant that suits them, and sometimes that’s traditional sand mastic. 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.
If you let a flat or house near Longfield station, sound mastic around windows and doors keeps out the draughts and damp that tenants notice first. For an older house near a landmark such as Church of Saint Mary Magdalene, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint.
Grubb Street is about 3 miles south-west of Northfleet, in Kent. Every kind of property in Grubb Street can book us for window mastic. The work is guaranteed for a year. Our Kent coverage runs to 922 places, Grubb Street among them. London is on our list too, around 17 miles away.
Work in DA2 is quoted and booked the same way as anywhere else. We also cover Green Street Green (1 mile north), Westwood (1 mile north-east), St Margarets (1 mile west), South Darenth (1 mile west) and Bean (1 mile north). Further out, we also cover Maidstone (14 miles south-east), Dartford (4 miles north-west), Sevenoaks (10 miles south-west), Gravesend (5 miles north-east), Tonbridge (14 miles south) and Northfleet (3 miles north-east).
Near you in Grubb Street
In Grubb Street, that means homes and buildings near Longfield Chalk Bank, Railway Tavern and Longfield Academy and the streets around them. The closest station to Grubb Street is Longfield station, about 1 mile south-east of the centre. A little further out are Stone Castle (2.6 miles north) and Darent Valley Hospital (2.3 miles north-west). For a walk, there’s Sawyers Lake.
Towns and villages near Grubb Street
Other services in Grubb Street
DIY versus a professional finish
A DIY attempt does not rule out a professional job. We cut it out and start again, so just mention it when you contact us.
Too much sealant is as bad as too little. A thick, smeared bead looks untidy and doesn’t move well, and the joint depth matters as much as the finish.
How the visit works
Before we leave, we go over the finished joints with you and tell you how long to leave it. The work normally takes a few hours for a handful of frames, longer for a whole house, depending on how much there is to do. In a small place like Grubb Street, access is usually the main thing to plan. If the job is outside, mention outbuildings, exposed walls and how to reach them.
- First, we go round the frames with you and agree the list.
- The old mastic is cut out and scraped back to clean surfaces.
- 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
- Mention if the joints have been sealed before
- For indoor joints, keep the area dry beforehand if you can
- Mention any sign-in or site rules at work premises
How to get a quote
There’s no standard price list, as no two jobs are quite the same. Instead, your job gets its own clear quote. To arrange one, ring 0345 464 0079 or drop us an email.