Greater London · England
Avery Hill Window Mastic
Window mastic in Avery Hill from a team with over 20 years’ experience. Rated 4.9 on Google from 180+ five-star reviews.
- Whistling draughts around closed windows
- Sealant in the wrong colour for the frame
- Cracked internal joints between frame and plaster
About our window mastic in Avery Hill
A window frame and the wall around it expand and shrink at different rates. Heat and cold make frames grow and shrink against brick or render that hardly moves. That is why the joint needs a flexible, low-modulus sealant rather than something rigid. Typical jobs include untidy mastic left by window fitters and rain getting in at the frame or under the sill, on patio & French doors, timber windows & doors and composite doors.
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.
Our work is backed for twelve months.
- Location
- Avery Hill (SE9, DA15, DA16)
- Wider area
- Greater London
- Cover
- One year on every job
- Quotes
- Quoted before any work starts
- Call
- 0345 464 0079
- Updated
- 26 October 2026
Window mastic in Avery Hill: local notes
The South East is one of the drier parts of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind. With historic houses such as Eltham Palace (about 1.2 miles west) nearby, there’s older building stock in the area around Avery Hill 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.
As a London address, Avery Hill can be tricky for parking: let us know about parking bays, permits or a driveway. For landlords with property near Falconwood station, renewing tired window mastic between tenants heads off draught and damp complaints. For site and facilities teams at buildings such as Stationers' Crown Woods Academy, larger buildings have plenty of frames, and the mastic around each one ages.
Avery Hill is about 1 mile north-east of Eltham, in Greater London. Whether you’re in the middle of Avery Hill or further out, we cover window mastic for every kind of property. Avery Hill is one of 764 towns and villages in Greater London we cover. We also work in London, around 8 miles away.
Our applicators cover all of SE9, DA15 and DA16 for window mastic. Whether your property is on Bexley Road, Glenure Road and Perpins Road or anywhere close by, we can help. You will find Avery Hill on the A210, so it’s easy for us to get to. Close by, we work in Blackfen (1 mile east), Eltham (1 mile south-west), New Eltham (1 mile south), Falconwood (1 mile north-east) and Well Hall (1 mile west). Within a short drive, we also cover London (8 miles north-west), City of Westminster (11 miles north-west), Marylebone (11 miles north-west), Kensington (12 miles west), St Pancras (10 miles north-west) and Shoreditch (8 miles north-west).
Local landmarks in Avery Hill
We work in homes and buildings around Shoulder of Mutton Green and Alderwood Primary School. The nearest railway station is Falconwood station, roughly 0.6 miles north. Well-known places in the area include Greenwich Castle (3.8 miles north-west) and Metropolitan Police Museum (1.7 miles south-east). Not far away are Summer Hill and The Tarn.
Landlord and commercial work in Avery Hill
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.
Whether it’s one flat or a portfolio, the work is the same standard: the old material taken out, careful preparation and a 12-month guarantee.
Places near Avery Hill
Other services in Avery Hill
Looking after it afterwards
Once the sealant has cured, a few habits help it last:
- Avoid harsh chemicals near the mastic
- Keep paint and stain on wooden frames in good order
- Look round the frames every year or so
- Don’t paint over the silicone
Silicone can’t normally be painted, so mention any painting plans before we start. There are paintable sealants for joints that need it.
On timber windows, water behind the joint can lead to rot. Once wood has rotted, it needs repair before it can be sealed, so it pays to reseal before that happens.
What sealant work cannot fix
We’ll always be straight with you, so here’s what new sealant won’t do:
- Damp coming through the wall itself rather than the frame joint
- A sash or casement that will not close properly
- A failed sealed unit that has misted up
Not sure which it is? You can ring 0345 464 0079 or drop us an email and we’ll tell you honestly.
Joints and surfaces we work on
- uPVC windows
- Window sills
- Patio & French doors
- Aluminium frames
- Timber windows & doors
- Composite doors
Should I try it myself first?
If you’re set on DIY, put the effort into preparation: take out all the old sealant, make sure the joint is clean and dry, and give it the full cure time. If it does not work out, we can still put it right.
The biggest DIY mistake is sealing over old sealant. Silicone does not stick to old silicone, so it lifts and traps water and mould underneath. All the old material has to come out first.
Questions from Avery Hill
Do you cover Avery Hill for window mastic?
Yes, Avery Hill is within the area we cover. We work across London and the South East. You can phone 0345 464 0079 or drop us an email and let us know what needs doing, and we’ll give you a clear quote.
I let a flat near Falconwood station. Can you help?
Yes. We work for landlords and letting agents as well as householders. Just call 0345 464 0079 or drop us an email with the address and what needs doing, and we’ll send you a clear quote.
Do you have insurance?
Yes. Full insurance covers our work.
Do I need to be at home?
For indoor joints, yes, someone needs to let us in. After that, you can carry on with your day.
Where do you work from?
We’re a Crawley-based firm, with over 20 years’ experience. We work across South East England, London and Scotland.
Can new sealant go over the old?
No. Fresh sealant doesn’t stick to old sealant, and anything trapped underneath, including mould and water, stays there. It all has to come out first.
How do I get a quote for window mastic in Avery Hill?
There’s no set price, as it depends on the job: its size, the old material, access and the product needed. We agree the price before any work begins.
Do you do commercial work?
Yes. Larger jobs can be planned room by room or area by area to suit the site.
What we do, step by step
When we arrive, we look over the joints with you first, so there are no surprises. Surfaces next to the work are protected before any work starts. Most jobs take most of a day for a typical house, less for a few frames. In Avery Hill, 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.
- We check how each frame can be reached safely.
- All the failed sealant is cut away, along with any loose debris.
- The surfaces are cleaned and left dry, and primed where the sealant calls for it.
- Deep voids are backed, then the sealant is gunned in.
- The joint is shaped to shed water and the area tidied.
Before we arrive
- Where the joints are inside, avoid wetting them before we arrive
- Plan for the work area to be out of bounds to pets and children
- Mention any parking rules near the property
Ask for a quote
If you’re in Avery Hill and need window mastic, phone 0345 464 0079 or drop us an email. Tell us what the problem is and where, and you will get a clear quote before work begins.
Read more
What affects the quote in Avery Hill
Call for a quick quote. The main things that affect it are:
- The number of rooms or windows
- How much there is to do
- Whether old sealant or filler has to be cut out
- When we can work, for business premises
Some things make a job bigger or smaller: how much old sealant there is and how stubborn it is, any mould to treat, and whether we need extra access for height. Your quote takes all of that into account.
Helping us quote
Photos help, but a description is a good start. Try to tell us:
- The type of property
- A few photos by email, if you can
- Any previous sealing or DIY work
- Roughly how big the job is
The more we know about the job, the more useful the quote. Let us know the location, the problem and roughly how many joints, and email photos if that’s easy.
What the job involves on each surface
uPVC windows
We clean the frame edge carefully so the plastic isn’t marked, then the sealant goes in between frame and wall.
Patio & French doors
The joints around patio doors run a long way, top, sides and threshold. The threshold and the bottom corners take the most water, so they get particular care.