Kent · England
Sand Mastic in Northfleet
Sand mastic in Northfleet from a team with over 20 years’ experience. 180+ five-star Google reviews and a 4.9 rating.
- Mastic that needs renewing before redecorating
- Mastic worn away on windows facing the weather
- Old cement repairs round a window that have failed
When to call us in Northfleet
Sand mastic slowly weathers. It dries out, cracks and loses its grip from the frame or the masonry.
Look out for any of the following:
- Draughty sash windows at the surround
- Patchy fillers round a sash window
- Window mastic to renew ahead of painting
- Open joints round the window box
If you live in an older home near Church of All Saints, frames set in older brick or stone need a sealant that suits the wall as well as the frame.
Before you book anyone
- How long to leave it before use
- Whether they seal over old material or remove it
- Who turns up on the day
- How the colour is chosen
About our sand mastic in Northfleet
Burnt sand mastic is a traditional material blends with stone and brick surrounds. It’s a good fit for period properties, where modern sealant can look out of place. We are often asked to deal with mastic that needs renewing before redecorating and cement or filler used on old window joints that has cracked, on sash and case windows, tenement windows and brick reveals.
Around Northfleet, many houses have gained conservatories, French doors or replacement windows over time. Each one adds more joints to look after, and those joints age at different rates. Leaks normally start at a sill, a frame head or a glazing joint.
There’s a 12-month guarantee on every job, large or small.
- Where
- Northfleet (DA11)
- Region
- Kent
- Cover
- A year, on every job
- Quote
- A clear price before work begins
- Phone
- 0345 464 0079
- Updated
- 26 October 2026
How the visit works
Our applicators work methodically: protection first, then preparation, sealing and a tidy-up. Typically it takes a few hours for a single window, longer for several and we leave things clean and tidy. Parking in a town like Northfleet is usually straightforward, but tell us if there’s a driveway or any restrictions, and let us know if the work is upstairs, in a flat or up high outside.
- We check each window surround and the condition of the joint.
- The joint is raked out and cleaned.
- Large voids are packed out.
- We point the joint with sand mastic by hand.
- We finish the mastic to a tidy line.
Before we arrive
- For business premises, tell us about site rules or sign-in
- Keep children and pets away from the work area
- Let us know about parking restrictions
How to get a quote
The more we know about the job, the more useful the quote. Tell us where the job is, what’s wrong and how much there is.
Advice
Places near Northfleet
What else we do in Northfleet
Common questions in Northfleet
Is sand mastic in a coastal place like Northfleet any different?
Near the sea, outside joints face more wind, rain and salt than they would inland, so the choice of sealant and the preparation matter even more. It’s worth checking the walls that face the sea first.
Do you work for landlords with property near Gravesend station?
Yes. We work for letting agents and landlords as well as homeowners, and several properties can go on one quote. You can call 0345 464 0079 or send us an email with the details for a clear quote.
Can old silicone round a sash window be swapped for sand mastic?
In most cases. We remove the silicone and clean the joint, then point it with sand mastic.
Do you hold any approvals?
Yes. We hold ARBOMaster approved applicator status and we’re fully insured too.
Do you have insurance?
Yes. Full insurance covers our work.
Which is right for my windows, sand mastic or modern sealant?
It depends on the window. Period windows in stone or brick usually suit sand mastic and newer frames generally get a flexible sealant.
What is sand mastic?
It’s the traditional filler for the joint round timber windows and doors. It combines sand with a linseed-oil-based binder.
Do I need to be at home?
It depends on the job. For work indoors, someone needs to let us in, and for outside work we will agree access with you when we book.
Why it’s worth doing now in Northfleet
New mastic over crumbling mastic won’t hold. We remove the loose material first so the new mastic stays put. Black mould and gaps in sealant do not fix themselves, and in a busy household in Northfleet they spread with every shower and every downpour. Replacing the sealant now is the simplest fix.
The cost depends on the size of the job, how hard the old material is to remove and how easy the joints are to reach. You’ll have a clear quote before any work starts.
Why Northfleet customers choose us
- Old sealant always removed completely
- 12-month guarantee on every job
- Over 20 years’ experience
- Sanitary silicone with an anti-fungal additive in wet areas
Read how sealant jobs are priced and customer reviews.
Aftercare tips
Aftercare is simple:
- Take care around the mastic when scraping paint
- Do not paint over the new mastic
- Do not run silicone over sand mastic
- Keep sills and gutters clear so water drains away
Avoid painting over the new mastic, as traditional guidance advises. If you’re redecorating, ask us first.
Fine cracks show the mastic is starting to fail. Renewing it then is simpler than waiting until it falls out.
When something else is needed
Sealant is not the answer to every problem, and we’d rather say so up front. Sealant won’t put right:
- Sash cords, weights and draught-proofing of the sashes
- Crumbling stone or brickwork round the window
- Decisions on consent for listed homes
If in doubt, call 0345 464 0079 or send us an email and we’ll say what we think before you book.
Joints and surfaces we work on
- Brick reveals
- Sash and case windows
- Tenement windows
- Timber door frames
- Period & listed homes
- Stone surrounds
What sand mastic looks like in Northfleet
Northfleet is within about 3 miles of the coast, and homes near the sea take more wind-driven rain, with salt in the air closer to the shore. Both are hard on the mastic around older windows and doors, which can dry out and crack sooner where a building faces the weather. Historic houses like Cobham College (about 3.7 miles south-east) are a reminder that the area around Northfleet has older buildings as well as new. In older buildings, older frames set in brick or stone need a sealant that suits them, and sometimes that is traditional sand mastic.
For site and facilities teams at buildings such as Northfleet Technology College, the mastic around its windows and doors needs looking after like any other building’s. Letting a property close to Gravesend station? Then any sash windows need sound mastic to keep draughts and rain out.
Northfleet is about 5 miles east of Dartford, in Kent. Wherever you are in the DA11 postcode area, our applicators can take on sand mastic. Northfleet is one of 922 places in Kent we cover for sand mastic. Our London page covers work nearby (20 miles or so).
Our applicators cover all of DA11 for sand mastic. We cover properties on Lawrance Square, London Road and Marks Square. Northfleet sits on or near the A2 and A226, which makes travel easy. We also cover the places around Northfleet: Painters Ash (1 mile south-west), Springhead (1 mile west), Windmill Hill (1 mile east), Northfleet Green (1 mile south) and Gravesend (1 mile east). Further out, we also cover Maidstone (14 miles south-east), Dartford (5 miles west), Sevenoaks (13 miles south-west), Swanley (8 miles west), Kings Hill (11 miles south) and Foley Park (13 miles south-east).
Around Northfleet
Around Northfleet, our work takes us to homes and buildings near The Six Bells pub, Saint George's Church of England School and Copperfield Academy and the streets around them. The nearest railway station is Gravesend station, roughly 1 mile north-east. Well-known places in the area include Bluewater (3.3 miles west) and Stone Castle (3.1 miles west). Not far away are Chafford Gorges Nature Park and Sawyers Lake.
Surface by surface
Sash and case windows
The mastic round a sash window is on show, so a neat, even finish matters.
Tenement and terrace windows
Rows of sash windows on tenements and terraces often need renewing together. We can do one window or several.
Landlord and commercial work in Northfleet
Whether it’s one flat or a portfolio, you get the same standard of work: old sealant fully removed, joints prepared properly and a one-year guarantee.
Letting agents often deal with us directly. Send the address, what’s needed and the access arrangements.