Greater London · England
Sand mastic for sash & case windows in North End, Greater London
We cover North End for traditional burnt sand mastic around sash and case windows and doors in stone and brick. Old sealant removed completely, joints prepared properly and a 12-month guarantee.
- Old cement repairs round a window that have failed
- Mastic worn away on windows facing the weather
- Gaps round a timber door in stone or brick
Should I try it myself first?
If you’ve already had a go yourself, that is fine. We remove it and do the joint properly, so tell us about it when you ask for a quote.
Some sealant jobs are within reach of a careful DIYer, such as a straightforward joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
Sand mastic for homes and businesses in North End
Silicone on a period window often looks wrong and isn’t always the right material. Sand mastic gives a finish that matches the age of the house and we can swap the silicone for it. If you’re dealing with open joints round the window box and draughty sash windows at the surround, we can help, whatever the surface.
Much of London’s older housing was built with timber sash windows, some still in place and some long since replaced. Either way, the mastic between frame and brickwork is what stops draughts and rain getting in.
Your job is guaranteed for a year, as with all our work.
- Location
- North End (DA8, DA1, DA7)
- Region
- Greater London
- Cover
- 12 months on all our work
- Quote
- A clear quote up front
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
Work for landlords, hotels and businesses
Landlords and letting agents in North End can book us as well as householders. Sealant work between tenants is a simple way to keep a property in good order.
We also work for businesses, from offices to washrooms and kitchens. On commercial sites, working times can be discussed when we quote.
Also near North End
Also in North End
Common problems we fix in North End
Shallow joints are a common cause. Mastic that is too thin cracks and drops out so we make sure the new mastic is the right thickness.
Any of these means the joints need attention:
- Old sand mastic that has cracked, crumbled or fallen out
- Gaps round a timber door in stone or brick
- A silicone bead on a sash window that spoils the look
- Weathered mastic on the most exposed windows
For an older house near a landmark such as St. Augustine's Church, frames set in older brick or stone need a sealant that suits the wall as well as the frame.
What to look for in a quote
- Which colour the sealant will be
- Is the old sealant removed completely?
- How long to leave it before use
- What happens if the job turns out different
Why it’s worth doing now in North End
If you are redecorating, renew the mastic first. Paint over cracked mastic won’t stop the gaps and traditional guidance is to leave the new mastic unpainted. In a flat in North End, 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.
We do not show prices on the website, because each job is priced on what it involves. For a quick quote, please ring 0345 464 0079 or drop us an email and we’ll talk you through it.
Why us?
- Fully insured
- Trusted Arbo and Everbuild sealants
- Neat joints and a tidy finish
- A 12-month guarantee on all work
Read how sealant jobs are priced and our reviews.
What happens on the day
Most of a good job is in the preparation, so that is where we spend the time. Every joint is cleaned and dried before new material goes in. In total, it normally takes anything from a few hours to a full day, depending on how many windows. In North End, flats, stairs and shared entrances are part of the routine. Mention any building rules, key holders or managing agents when you book.
- We check each window surround and the condition of the joint.
- We rake out the old mastic and clean the joint.
- We fill deep gaps so the new mastic is not too thick.
- New sand mastic is applied and shaped by hand.
- We finish the mastic to a tidy line.
Before we arrive
- Move anything stored near the joints
- Let us know about earlier repairs to the joints
- Plan for the work area to be out of bounds to pets and children
Ask for a quote
It all starts with a short chat. Describe the problem, the location and the size of the job, and we’ll talk you through what we’d do. When it suits you, phone 0345 464 0079 or drop us an email.
Read more
Aftercare tips
So the new joints stay in good condition:
- Inspect the joints round the windows every year or so
- Find out about consent before window work on a listed home
- Get any rot dealt with first
- Leave the new mastic unpainted
Don’t run silicone over the new mastic. If anything cracks, get it looked at rather than patching it.
Renewing mastic before redecorating saves doing it twice. Paint over cracked mastic only covers it up.
North End questions
Can you help a landlord with a rental near Slade Green station?
Yes, landlords and agents are among the people we work for, and several properties can be quoted together. You can call 0345 464 0079 or email us with the details for a clear quote.
Can you do sand mastic in North End?
Yes, North End is within the area we cover. We work across London and the South East. You can call 0345 464 0079 or send us an email and let us know what needs doing.
Do you guarantee sand mastic work?
Our 12-month guarantee covers every job.
Do you work for hotels and businesses?
Yes, regularly. We can plan bigger jobs in stages.
How do I get a quote for sand mastic in North End?
Size, access and the old material all affect the cost. Ask us for a quote and we’ll talk you through it.
Do you have insurance?
Yes, we are fully insured.
Will the old sealant be removed?
Yes, always, and completely. New silicone doesn’t stick to old silicone, so any old material comes out before anything new goes in.
Do I need permission for sand mastic on a listed building?
Check with your local planning authority. They’ll tell you if consent is needed for work to your windows.
When something else is needed
Before booking, it’s worth knowing the limits:
- Whether work needs listed building consent
- Broken panes
- Timber that has rotted
Not sure which it is? You can phone 0345 464 0079 or send us an email and we will tell you honestly before you book.
Where we work in North End
- Timber door frames
- Tenement windows
- Stone surrounds
- Brick reveals
- Period & listed homes
- Sash and case windows
North End homes and the weather
In London conversions and blocks, the lease decides who is responsible for the frames, so check that before you book. With historic houses such as Hall Place and Gardens (about 2 miles south-west) nearby, there’s older building stock in the area around North End as well as newer homes. Where a home is older, older frames set in brick or stone need a sealant that suits them, and sometimes that is traditional sand mastic.
As a London address, North End can be tricky for parking: tell us about permits, visitor bays or off-street space when you book. Schools such as St. Paul's (Slade Green) Church of England Primary School are buildings too, and its window and door frames need their mastic kept sound, just like a home’s.
North End is about 2 miles north-west of Dartford, in Greater London. From the centre of North End to the outskirts, we cover sand mastic for every kind of property, from flats and houses to offices and hotels. We cover 764 towns and villages across Greater London, from the larger towns to small villages. London is on our list too, about 13 miles from North End.
Here we cover the DA8, DA1 and DA7 postcode area for sand mastic. Whether your property is on Oak Road, Elm Road and Moat Lane or anywhere close by, we can help. Close by, we work in Slade Green (1 mile east), Barnes Cray (1 mile south), Bexley Riverside (1 mile west), Barnehurst (1 mile west) and Northumberland Heath (1 mile west). Within a short drive, we also cover London (13 miles west), City of Westminster (15 miles west), Marylebone (15 miles west), St Pancras (14 miles west), Shoreditch (12 miles west) and Walthamstow (13 miles north-west).
Landmarks near North End
Locally, jobs take us to homes and businesses close to Railway Tavern, Braeburn Park and Haberdashers' Aske's Crayford Academy, among other places. There’s a railway station in North End itself: Slade Green station. A little further out are Erith Museum (1.2 miles north-west) and Erith and District Hospital (1.4 miles north-west). Not far away are Wansunt Pit.