Greater London · England
Sanderstead Window Mastic
Window mastic for Sanderstead and the surrounding area: careful preparation, the right product and tidy work. Ask us for a quick quote.
- Draughty joints inside around the window
- Water coming in at the bottom corners of a door
- Whistling draughts around closed windows
Common problems we fix in Sanderstead
Water runs down the glass onto the sill, so the sill ends and the joint below the frame are common leak points. When that sealant fails, water gets into the wall or under the frame.
These are the problems we’re asked about most:
- Whistling draughts around closed windows
- Cracked sealant at the sill ends
- Hard, cracked sealant around windows
- Gaps between the frame and the inside reveal
If you live in an older home near Church of All Saints, the windows may be timber, sash or later replacements, and each needs the right sealant against the wall.
What your quote should include
- How the joint is cleaned and prepared
- Whether they seal over old material or remove it
- What insurance they hold
- What happens if the job turns out different
Window mastic for homes and businesses in Sanderstead
There are two joints on most windows. Outside, the mastic keeps rain out; inside, the joint between frame and plaster stops draughts and tidies the reveal. We seal one or both, depending on what’s needed. We work on aluminium frames, timber windows & doors and window sills, and the jobs we see most are leaking joints at the ends of sills and hard, cracked sealant around windows.
From mansion-block windows to modern glazing in new flats, London has every kind of frame. The mastic around them dries out and cracks with age, letting in draughts and water.
Each job carries a 12-month guarantee.
- Location
- Sanderstead (CR2, CR8)
- Wider area
- Greater London
- Guarantee
- A year, on every job
- Price
- Quoted before any work starts
- Phone
- 0345 464 0079
- Updated
- 26 October 2026
Also near Sanderstead
Also in Sanderstead
Why act early in Sanderstead
Choosing the product is half the job. Interior caulk and bathroom silicone are not made for exterior frame joints. An exterior, low-modulus sealant stays flexible in sun and frost. In a flat in Sanderstead, failed sealant seldom stays inside your own four walls: water from a shower or window joint can reach the flat below, and gaps in fire-stopping matter to everyone in the building.
Leaving a failed joint generally makes the job bigger, not smaller, as water and mould keep getting in. If you’re not sure whether it needs doing, phone 0345 464 0079 or send us an email for an honest opinion and a quote.
What you get with us
- 4.9 on Google from 180+ five-star reviews
- Full insurance on every job
- A 12-month guarantee on all work
- Approved under the ARBOMaster scheme
Read what affects the cost or what customers say.
Frames and glazing around Sanderstead
In a converted house or block, who looks after the windows depends on the lease, so check that before booking. With historic houses such as Addington Palace (about 2.3 miles north-east) nearby, there’s older building stock in the area around Sanderstead 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.
Letting a property close to Riddlesdown station? Then cracked frame mastic tends to show up as a draught or damp complaint, so it’s worth checking between lets. Schools such as Gresham Primary School are buildings too, and larger buildings have plenty of frames, and the mastic around each one ages.
Sanderstead is about 2 miles east of Purley, in Greater London. Homes, rented property, offices and hotels in Sanderstead can book us for window mastic. The work is guaranteed for a year. Across Greater London, we cover 764 places, and Sanderstead is one of them. Our London page covers work nearby (11 miles or so).
Here we cover the CR2 and CR8 postcode area for window mastic. If you need window mastic at a property on Hyde Road, Brian Avenue and Sundown Avenue or a nearby road, our applicators can take on the job. With the A2022 close by, Sanderstead is simple for us to get to for window mastic. Neighbouring places we cover for window mastic include Riddlesdown (1 mile south-west), Kenley (1 mile south-west), South Croydon (1 mile north-west), Selsdon (1 mile north-east) and Hamsey Green (1 mile south-east). We also work in nearby towns such as London (11 miles north), City of Westminster (13 miles north), Marylebone (13 miles north), Kensington (12 miles north-west), St Pancras (13 miles north) and Shoreditch (13 miles north).
Near you in Sanderstead
Typical jobs here are in homes near Selsdon Park Hotel, Littleheath Woods and Riddlesdown Collegiate. Sanderstead’s nearest station is Riddlesdown station, about 0.8 miles west of the centre. A little further out are Purley War Memorial Hospital (1.4 miles west) and Croydon Airport Visitor Centre (2.1 miles north-west). Green spaces nearby include Duppas Hill and Foxley Wood.
What affects the cost of window mastic
Every job gets its own quote. These are the things that affect it:
- Mould in or behind the old joints
- Working hours on commercial sites
- How much old sealant there is and how hard it is to remove
- The product the joint needs
Rather than a set price list, we price the job in front of us: how many joints, what’s in them now and how we reach them. You will know the price before we begin.
Helping us quote
A few details help us give you an accurate quote. When you get in contact, it helps to mention:
- Any previous sealing or DIY work
- A few pictures by email, if you can
- Where the property is
- How many joints, rooms or windows are involved
The more we know about the job, the more useful the quote. Let us know the location, the problem and roughly how many joints.
Different surfaces, different methods
Window sills
The end joints of a sill tend to fail before the rest. A tight seal at each end keeps rain out of the wall.
Patio & French doors
Heavy door frames can move more than windows. A flexible sealant copes with that without cracking.
What sealant work can’t fix
Sealant isn’t the answer to every problem, and we’ll tell you before any work starts. Sealant won’t put right:
- Broken hinges, locks or handles
- Damp coming through the wall itself rather than the frame joint
- Soft or decayed wood in the frame
Not sure which it is? You can ring 0345 464 0079 or send us an email and we’ll tell you honestly.
Surfaces we seal
- Composite doors
- Timber windows & doors
- uPVC windows
- Aluminium frames
- Window sills
- Patio & French doors
What we do, step by step
There’s no need to move everything out before we come, just the space around the work. We protect the rest, and the job takes anything from an hour or two to a full day, depending on how many frames there are in most cases. For a job in Sanderstead, parking and access are the things to plan: tell us about permits, visitor bays or off-street space, which floor we’re working on and whether there’s a lift.
- First, we go round the frames with you and agree the list.
- We remove the old mastic and clean the frame edge and wall.
- Where the gap is deep, backing rod goes in first.
- A flexible exterior sealant is applied in a colour to suit the frame.
- Every joint is tooled smooth and checked before we leave.
Getting ready for the visit
- Tell us about any water getting in
- Mention if the joints have been sealed before
- On commercial sites, let us know about site rules
Ask for a quote
We don’t publish a price list, because every job is different. Instead, your job gets its own clear quote. To get started, ring 0345 464 0079 or send us an email.
Related advice
Landlord and commercial work in Sanderstead
In hotels, rooms out of use cost money, so we plan the work room by room. We have worked in hotels as well as homes and businesses.
Failed sealant is one of the commonest items on a check-out report, and it’s quick to put right between tenancies. Several properties can be quoted together.
Sanderstead: your questions answered
Can you help a landlord with a rental near Riddlesdown station?
Yes. We work for landlords and agents as well as homeowners, and several properties can go on one quote. Just phone 0345 464 0079 or drop us an email with the address and what needs doing, and we’ll give you a clear price.
Do you cover Sanderstead for window mastic?
Yes, Sanderstead is within the area we cover. Our work covers London and the South East. You can call 0345 464 0079 or drop us an email and tell us what needs doing.
Will you leave a mess?
We keep the work tidy. Nearby surfaces are protected, and the area is left clean when we finish.
Should I try DIY first?
That depends on the joint. Work at height, movement joints, fire-rated gaps and large areas are best left to a professional, while a short indoor joint may be within reach.
How long should I leave it?
Different products cure at different speeds, so follow the cure time we give you.
Do you do commercial work?
Yes. Commercial and hotel work is a large part of what we do. We can talk about working times when we quote.
Do you remove the old sealant?
Yes, always, and completely. New silicone does not stick to old silicone, so any old material comes out before anything new goes in.
Can you get sealant to suit coloured frames?
Yes. Anthracite grey, black, brown and white cover most frames, with clear as an option.