Greater London · England
Shortlands Window Mastic
Window mastic for Shortlands, by sealant specialists with 20+ years’ experience. Rated 4.9 on Google from 180+ five-star reviews.
- Whistling draughts around closed windows
- White mastic on grey or black frames
- Old mastic that has gone black or come away
Window mastic in Shortlands, done properly
From a single sill to a whole house of windows, the work is priced before anything is done. To get one, phone 0345 464 0079 or drop us an email with the number of frames and any access details. We’re often asked to deal with cold air getting in at the frame edge and leaking joints at the ends of sills, on composite doors, aluminium frames and timber windows & doors.
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.
A 12-month guarantee comes as standard.
- Place
- Shortlands (BR2, BR1, BR3)
- Region
- Greater London
- Guarantee
- One year on every job
- Price
- A clear price before any work starts
- Call
- 0345 464 0079
- Last updated
- 26 October 2026
What affects the cost of window mastic
We do not publish a price list. The quote depends on:
- Any working-time requirements on site
- The product the joint needs
- The number of rooms or windows
- Whether the work is at height
The cost reflects the work involved, not guesswork. That is why we ask a few questions first and give you a clear quote before any work starts.
What we need to know
There’s no need for technical detail. It helps if you can tell us:
- Whether it has been sealed before
- Photos by email, if that is easy
- The type of property
- Roughly how big the job is
For a quick quote, get us on the phone, or send an email if you’d rather. Tell us about the joints that need doing and we’ll talk you through the work.
FAQs for Shortlands
Can parking be tricky for a visit in Shortlands?
London parking needs a little planning, so let us know about permits, bays or a driveway when you book. The visit is then planned around what’s available.
Can you do window mastic in Shortlands?
Yes, Shortlands is within the area we cover. Our work covers London and the South East. You can phone 0345 464 0079 or email us and tell us what needs doing, and we’ll give you a clear price.
How long does it take to reseal the windows on a house?
The work takes a morning for a couple of windows and a door. Access and how stubborn the old mastic is affect the time most.
Do I have to be there?
We need access to the joints, so we’ll agree that with you when we book. Indoors, that usually means someone at home.
Do you have insurance?
Yes, we’re fully insured for every job we do.
Can resealing stop a draught around my window?
Yes, where the draught is at the frame edge. We find where the air is coming from before we reseal.
Is there any odour?
Some sealants have a smell while they cure, but it fades. Ventilation helps.
Do you work for landlords and businesses?
Yes. Domestic, commercial and hotel work are all part of what we do.
Looking after it afterwards
Joint life depends on how it’s used and looked after. We suggest:
- Repaint timber before it’s bare
- Don’t aim a pressure washer at the joints
- Wash the frames with mild soapy water
- Make sure the drainage slots are not blocked
Try not to touch the new joint while it cures, following the cure time we give you. Keep jet washers away from the frames.
Leaks generally show up in wet, windy weather, but resealing works best in dry conditions. Dealing with it when you first notice a crack avoids chasing leaks through the wet months.
Signs you need window mastic in Shortlands
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.
Most people get in touch after spotting something like this:
- Old mastic that has gone black or come away
- Draughts coming in around windows and doors
- Gaps left after new windows were fitted
- Gaps where the sill meets the wall
Shortlands is in London, so parking needs planning: tell us about permits, visitor bays or off-street space when you book.
Questions to ask before you book
- What insurance they hold
- How the surfaces are prepared before sealing
- Which colour the sealant will be
- What the cure time is
How it works
At the end, we look at the finished work together and tell you how long to leave it. The visit itself normally takes anything from an hour or two to a full day, depending on how many frames there are, depending on the size of the job. For a job in Shortlands, parking and access are the things to plan: tell us about permits, visitor bays or off-street space, which floor we are working on and whether there’s a lift.
- First, we confirm safe access to each frame.
- All the failed sealant is cut away, along with any loose debris.
- Frame and wall are cleaned and must be dry before sealing.
- Backing rod fills deep voids and the sealant goes in on top.
- The joint is shaped to shed water and the area tidied.
How to prepare
- Tell us about access, such as stairs, a lift or high-level joints
- Plan for the work area to be out of bounds to pets and children
- For indoor joints, keep the area dry beforehand if you can
Ask for a quote
If you are in Shortlands and need window mastic, phone 0345 464 0079 or send us an email. A short description of the job and where it is helps us quote, and we’ll agree the price before any work begins.
Related advice
Work for landlords, hotels and businesses
Failed sealant is one of the commonest items on a check-out report. Several properties can go on one quote.
We also work for businesses, from offices to washrooms and kitchens. For commercial premises, we can talk through working times when we quote.
When something else is needed
A few problems are outside what sealant work can do:
- A failed sealed unit that has misted up
- Damp problems in the wall away from the window
- Broken hinges, locks or handles
If you are not sure, just ring 0345 464 0079 or send us an email and we’ll give you a straight answer before you book.
What we seal
- Timber windows & doors
- Composite doors
- Window sills
- Patio & French doors
- uPVC windows
- Aluminium frames
Windows and doors in Shortlands
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 check that before booking.
For an older house near a landmark such as St Mark's Church, the windows may be timber, sash or later replacements, and each needs the right sealant against the wall. For site and facilities teams at buildings such as Highfield Infants' School, its window and door frames need their mastic kept sound, just like a home’s.
Shortlands is about 1 mile south-west of Bromley, in Greater London. For window mastic in and around Shortlands, please ring 0345 464 0079 or send us an email for a quick quote. We cover Greater London from our Crawley base, Shortlands included. Shortlands is one of 764 places in Greater London where we work for window mastic. You can also see our page for London, about 8 miles away.
Every address in BR2, BR1 and BR3 is covered for window mastic. Whether your property is on Hayes Lane, Stone Road and Hayes Road or a nearby road, our applicators can take on the job. We also cover the places around Shortlands: Eden Park (1 mile south-west), Hayes (2 miles south), Bromley Common (2 miles south-east), West Wickham (2 miles south-west) and Southborough (2 miles east). Larger places within reach include London (8 miles north-west), City of Westminster (10 miles north-west), Marylebone (11 miles north-west), Kensington (11 miles north-west), St Pancras (10 miles north-west) and Shoreditch (10 miles north).
Landmarks near Shortlands
We work in homes and buildings around The Richmal Crompton pub, Church House Gardens and Langley Park School for Girls and the streets around them. For rail, the closest station is Shortlands station, about 0.5 miles north. A little further out are Bromley Hospital (0.7 miles east) and Bethlem Museum of the Mind (1.6 miles south-east). Green spaces nearby include Summer Hill and Downham Woodland Walk.
How the job changes by surface
Window sills
Every drop off the glass ends up on the sill, so the joints at each end and underneath matter. Each is cleaned out and resealed.
Patio & French doors
Not every patio door leak is a mastic problem: blocked drain slots, worn brush seals and threshold details can let water in too. We look for the cause first.