Kent · England
Northdown Sand Mastic
Sand mastic for Northdown, by sealant specialists with 20+ years’ experience. 180+ five-star Google reviews and a 4.9 rating.
- Gaps round a timber door in stone or brick
- Old sand mastic that has cracked, crumbled or fallen out
- Draughts and rain around sash boxes
How the job changes by surface
Stone surrounds
The stone is treated with care while raking out the old mastic.
Tenement and terrace windows
Where a building is shared, window work may involve neighbours so it’s worth checking responsibilities.
Sand mastic in Northdown, done properly
A silicone bead around a sash window can look out of place and isn’t always the right material. Sand mastic is the traditional choice, and we can replace one with the other. Typical jobs include tired mastic found when preparing windows for paint and cement or filler used on old window joints that has cracked, across brick reveals, timber door frames and stone surrounds.
Homes around Northdown range from older properties to newer houses, and their windows range just as widely. Each frame material needs the right sealant against the right wall.
We stand behind the work with a 12-month guarantee, so you’re not left on your own once the job is done.
- Where
- Northdown (CT9, CT10)
- Region
- Kent
- Guarantee
- A year, on every job
- Quote
- A clear price before work begins
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
Towns and villages near Northdown
What else we do in Northdown
Looking after it afterwards
Once the sealant has cured, a few habits help it last:
- Sort the mastic before the decorators arrive
- Avoid heavy scraping on the mastic joint
- Inspect the joints round the windows every year or so
- Don’t run silicone over sand mastic
Avoid sealing over the mastic with silicone. If you see a crack, ask us to take a look rather than patching it.
It’s best to renew mastic before painting the windows. Painting over failed mastic hides the problem for a while.
DIY sealant or a professional job?
If you are set on DIY, put the effort into preparation: remove every trace of old sealant, clean and dry the joint, and follow the product’s cure time. If it doesn’t work out, we can still put it right.
Overfilling a joint is a classic DIY mistake. A thick, smeared bead looks untidy and does not move well, and the joint depth matters as much as the finish.
Work for landlords, hotels and businesses
For anyone letting property in or around Northdown, several properties can go on one quote. Send us the addresses and the work at each.
Water getting past a failed joint can damage the building, which is a bigger problem in a rented property. Resealing at the right time is simple maintenance.
Common questions in Northdown
Is Northdown within the area you cover?
Yes. Northdown is within the area we cover, which takes in towns, villages and rural addresses. Our work covers London and the South East. Let us know about access, parking and anything unusual about getting there when you book.
Does the coastal weather in Northdown affect outside sealant?
Coastal weather is harder on outside sealant: there’s more wind-driven rain and, closer to the shore, salt in the air. Choosing the right sealant for the frame and wall, laid at the right depth, helps it last.
Can you do several jobs on one visit?
Yes. Just list everything you need and you will get one quote.
Is there any odour?
It depends on the product. Some products have a noticeable smell, others very little.
I’m a tenant. Can you help?
Of course. Check with your landlord; we can send the quote to them too.
How much does sand mastic cost in Northdown?
Size, access and the old material all affect the cost. Ask us for a quote and we will talk you through it.
What guarantee comes with the work?
Our 12-month guarantee covers every job.
Are you insured?
Yes. We’re fully insured.
The process
When we get to you, we check the joints match what you told us. If we find something unexpected, we talk it through with you first. Most jobs then take a few hours per window, depending on the condition of the joints. In a smaller place like Northdown, parking is seldom the issue; lanes, gates and long drives are worth mentioning. For outside work, side access and the height of the joints help us plan.
- We check each window surround and the condition of the joint.
- We rake out the old mastic and clean the joint.
- Large voids are packed out.
- New sand mastic is applied and shaped by hand.
- We finish the mastic to a tidy line.
Preparing for the visit
- Mention any tricky access
- Where the joints are inside, avoid wetting them before we arrive
- Clear the area around the work
Get a quote
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 pictures if that is easy.
Related advice
Sand mastic in Northdown: local notes
Northdown is within about 1 mile of the coast, where wind-driven rain is a fact of life and, nearer the shore, so is salt air. Both are hard on the mastic around older windows and doors, which can dry out and crack sooner where a building faces the weather. With historic houses such as Quex Park (about 4.5 miles west) nearby, there’s older building stock in the area around Northdown as well as newer homes. Where a home is older, older timber frames in brick or stone need a different approach from a modern uPVC window.
If you live in an older home near St Philip, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint. If you look after a building such as Palm Bay Primary School, the mastic around its windows and doors needs looking after like any other building’s.
Northdown is about 2 miles east of Margate, in Kent. For sand mastic in and around Northdown, please ring 0345 464 0079 or send us an email for a quick quote. We are based in Crawley and cover Kent. Across Kent, we cover 922 places, Northdown among them. There’s also a page for Chelmsford, roughly 47 miles from Northdown.
Work in CT9 and CT10 works the same way as everywhere else we cover. We cover properties on Old Road, Holly Lane and Green Lane. We also cover the places around Northdown: Palm Bay (1 mile north-west), Cliftonville (1 mile west), Kingsgate (1 mile east), St Peter's (1 mile south) and Broadstairs (2 miles south). Within a short drive, we also cover Ramsgate (3 miles south), Deal (12 miles south), Herne Bay (12 miles west), Walmer (13 miles south), St Lawrence (3 miles south) and Newington (3 miles south-west).
Local landmarks in Northdown
Typical jobs here are in homes near Captain Digby Inn and Dane Court Grammar School. The nearest railway station is Broadstairs station, roughly 1.8 miles south. A little further out are Westwood Cross (2.1 miles south-west) and Queen Elizabeth the Queen Mother Hospital (1.4 miles south-west).
When something else is needed
We’d rather tell you now than do work that won’t last, so these are the limits:
- Rotten sashes, sills or window boxes (a joiner’s job)
- Sashes that need overhauling
- Masonry that needs repairing
If you are not sure, just phone 0345 464 0079 or send us an email and we will give you a straight answer.
Joints and surfaces we work on
- Tenement windows
- Stone surrounds
- Period & listed homes
- Brick reveals
- Sash and case windows
- Timber door frames
Do you need sand mastic in Northdown?
Decorating can disturb tired mastic. It’s often found when windows are being prepared for paint, which is a good time to renew it.
The most common problems we see are:
- Gaps where the frame meets the masonry
- Mastic round period door frames that has failed
- Mastic dropping out of the joint
- Draughty sash windows at the surround
If you let a flat or house near Broadstairs station, any sash windows need sound mastic to keep draughts and rain out.
What to look for in a quote
- What preparation is included
- What guarantee comes with the work
- Who does the work, and how experienced they are
- How hidden problems are handled