Greater London · England
Window Mastic in St Mary Cray
Problem with your window and door frames in St Mary Cray? We remove the old material, prepare the joints and seal them properly, with a one-year guarantee.
- Old mastic that has gone black or come away
- A bead that doesn’t match the frame
- Leaking joints at the ends of sills
About our window mastic in St Mary Cray
From a single sill to a whole house of windows, you will get a clear quote before work begins. To get one, phone 0345 464 0079 or send us an email with the number of frames and any access details for window mastic in St Mary Cray. We work on patio & French doors, aluminium frames and composite doors, and common reasons people get in touch are gaps where the sill meets the wall and hard, cracked sealant around windows.
London has a lot of flats and conversions, where windows are often on upper floors. Who looks after the outside of the frames can depend on the lease, so check that first, and access in St Mary Cray is something to talk through when you book.
There’s a 12-month guarantee on every job, whatever its size.
- Location
- St Mary Cray (BR5, BR6, BR7)
- Region
- Greater London
- Cover
- A year, on every job
- Quotes
- A clear price before work begins
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
How it works
Good joint work is mostly preparation, and we do not rush it. Joints are cleaned back and dried before anything new goes in. In total, it generally takes a few hours for a few frames, or a day or more for a whole house. In St Mary Cray, flats, stairs and shared entrances are part of the routine. If the building has a concierge, managing agent or access rules, tell us when you book.
- First we look at every frame and agree the list.
- Next the failed sealant is cut away and the joint cleaned.
- Deep gaps are filled with backing rod to set the depth.
- New exterior sealant goes on in a matching colour and is tooled smooth.
- Finally we tidy up and check each joint.
Before we arrive
- Clear the area around the work
- Mention if the joints have been sealed before
- Let us know about parking restrictions
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. Whenever you’re ready, ring 0345 464 0079 or email us.
Advice
Quotes for window mastic in St Mary Cray
Call for a quick quote. The main things that affect it are:
- How many rooms, windows or areas are involved
- The size of the job
- How easy the joints are to reach
- When we can work, for business premises
Commercial jobs are quoted on the same basis as homes: the amount of work, how we reach it and what it needs, along with when we can work on site. Ask us for a quote and we’ll go through it with you.
Asking for a quote
When you contact us, it’s useful to know:
- Photos by email, if that’s easy
- Where the property is
- The type of property
- Any previous sealing or DIY work
A good description makes for an accurate quote. Tell us where the job is, what’s wrong and how much there is, and add photos by email if you can.
Do you need window mastic in St Mary Cray?
Mastic ages in the weather. Sunlight dries the surface out, until it loses its stretch and starts to crack.
It’s worth asking for a quote if you see:
- Gaps between the frame and the inside reveal
- Untidy mastic left by window fitters
- Water coming in at the bottom corners of a door
- Cold air getting in at the frame edge
Managing a site like Poverest Primary School? Then larger buildings have plenty of frames, and the mastic around each one ages.
What to look for in a quote
- Which colour the sealant will be
- Are they insured?
- What guarantee comes with the work
- Who does the work, and how experienced they are
Places near St Mary Cray
More services for St Mary Cray
St Mary Cray questions
Do you cover St Mary Cray for window mastic?
Yes, St Mary Cray is within the area we cover. We work across London and the South East. Just call 0345 464 0079 or send us an email with a few details of the job, and we’ll give you a clear price.
Do you work for landlords with property near St Mary Cray station?
Yes, we work for letting agents and landlords. You can ring 0345 464 0079 or email us with the address and a few details, and we will give you a fixed price before work begins.
Will the old sealant be removed?
Yes, every time. New silicone does not stick to old silicone, so the joint is cleaned back first.
Is it OK to seal over old sealant?
No, it will not last. It can look neat for a few weeks, but the new bead soon lifts. Removing the old sealant completely is the only lasting way.
Do you have sealant for grey or black windows?
Yes. We can use white, brown, anthracite grey, black or clear.
Do the sealants smell?
There can be a smell while the sealant cures, but it fades. Ventilation helps.
Is the new sealant paintable?
Most silicone can’t be painted. Let us know beforehand, and we’ll use a paintable product where it suits.
Is it worth trying it myself?
It depends on the job. Work at height, movement joints, fire-rated gaps and large areas are best left to a professional.
DIY sealant or a professional job?
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 jobs are best left to a professional: work at height, external movement joints, fire-rated sealant and large areas need the right product, the right access and the right method.
How to look after the new joints
To keep the joints looking good and working properly:
- Use gentle cleaners on frames and sealant
- Don’t paint over the silicone
- Keep jet washers away from the mastic
- Keep timber frames painted
Wipe the frames with soapy water when you clean the windows, and keep solvents and harsh chemicals off the joint.
Draughts get worse, not better. As old mastic keeps shrinking, the gap widens, and heat escapes around the frame. Resealing closes it.
What happens if it’s left?
A quick bead over the top of old mastic looks like an easy fix, but new sealant can’t bond to old, crumbling mastic. It soon lifts and the leak carries on behind it. The old mastic has to come out. In a London flat, a failed joint rarely stays your problem alone: water from a shower or window joint can reach the flat below, and gaps in fire-stopping matter to everyone in the building.
There are no prices on our website, because each job is priced on what it involves. For a quick quote, please phone 0345 464 0079 or send us an email.
Why St Mary Cray clients choose us
- A 12-month guarantee on all work
- A sealant colour to suit the surroundings
- Experience in homes, commercial sites and hotels
- A choice of colours where the product allows
St Mary Cray homes and the weather
In London conversions and blocks, the lease decides who is responsible for the frames, so it’s worth checking before booking. With historic houses such as Bromley Palace (about 3.8 miles west) nearby, there’s older building stock in the area around St Mary Cray as well as newer homes. In older buildings, older frames set in brick or stone need a sealant that suits them, and sometimes that’s traditional sand mastic.
Rented homes near St Mary Cray station change hands often, and sound mastic around windows and doors keeps out the draughts and damp that tenants notice first. St Mary Cray is in London, so parking needs planning: let us know about parking bays, permits or a driveway.
St Mary Cray is about 11 miles south-east of London, in Greater London. Anywhere in BR5, we can carry out window mastic at your property. Across Greater London, we cover 764 places, and St Mary Cray is one of them. London is on our list too, about 11 miles from St Mary Cray.
Our applicators cover all of the BR5, BR6 and BR7 postcode area for window mastic. Whether your property is on New Road, Kent Road and Park Road or a nearby road, we can help. With the A224 close by, St Mary Cray is easy for our applicators to reach for window mastic. We also cover the places around St Mary Cray: Poverest (1 mile south-west), St Paul's Cray (1 mile north), Orpington (1 mile south), Derry Downs (1 mile south-east) and Kevington (1 mile east). We also work in nearby towns such as London (11 miles north-west), City of Westminster (14 miles north-west), Marylebone (14 miles north-west), Kensington (15 miles north-west), St Pancras (13 miles north-west) and Shoreditch (12 miles north-west).
Near you in St Mary Cray
Around St Mary Cray, our work takes us to homes and buildings near Harris Academy Orpington, The Blue Anchor Public House and Walsingham School and the streets around them. There’s a railway station in St Mary Cray itself: St Mary Cray station. Well-known places in the area include London Borough of Bromley Museum (0.9 miles south) and Lullingstone Castle (4.5 miles south-east). Open spaces near St Mary Cray include Summer Hill and The Warren.
When it isn’t the sealant
In fairness, there are a few things sealant won’t fix:
- Soft or decayed wood in the frame
- Broken hinges, locks or handles
- Damp coming through the wall itself rather than the frame joint
If in doubt, phone 0345 464 0079 or drop us an email and we’ll say what we think before booking.
Joints and surfaces we work on
- Timber windows & doors
- Window sills
- Composite doors
- uPVC windows
- Patio & French doors
- Aluminium frames