Kent · England
Southfleet Window Mastic
Window mastic for Southfleet, by sealant specialists with 20+ years’ experience. 180+ five-star Google reviews and a 4.9 rating.
- Rain getting in at the frame or under the sill
- Old mastic that has gone black or come away
- A bead that does not match the frame
Window mastic in Southfleet, done properly
If you can feel air around a shut window, the gap is often at the frame. Resealing that joint can make a room feel noticeably less draughty and quietens the whistle on windy days. If the draught is through the window seals instead, we’ll tell you. We work on window sills, aluminium frames and timber windows & doors, and the jobs we see most are damp patches on the reveal after heavy rain and mastic that has split away from the wall.
In a village or hamlet like Southfleet, older cottages and farmhouses often have timber windows set in stone or brick. Older buildings like these don’t always suit modern silicone, so the sealant has to be chosen to suit the building.
The work is covered for a year after we finish. If anything isn’t right with it, phone 0345 464 0079 or drop us an email.
- Place
- Southfleet (DA13)
- Region
- Kent
- Cover
- One year on every job
- Quote
- A clear price before we start
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
What we do, step by step
There is not much for you to do on the day. Show us the job and we will take it from there. The work itself takes anything from an hour or two to a full day, depending on how many frames there are from start to finish. In a small place like Southfleet, access is generally the main thing to plan. For outside work, also let us know about exposed walls and any outbuildings involved.
- First, we confirm safe access to each frame.
- All the failed sealant is cut away, along with any loose debris.
- The surfaces are cleaned and left dry.
- Deep voids are backed, then the sealant is gunned in.
- We tool the joint so water runs off, then clear up.
How to prepare
- Mention any tricky access
- Tell us about any water getting in
- On commercial sites, let us know about site rules
Getting a quote
We quote each job on its own, so start by telling us what you need. Just ring 0345 464 0079 or email us with the details.
Read more
How we quote for window mastic
For a quick quote, just ask. The main things that affect it are:
- How much there is to do
- When we can work, for business premises
- Any mould that needs treating
- The old material and how stubborn it is
A few things move the cost up or down: how much old sealant there is and how stubborn it is, any mould to treat, and whether the work is at height. We take all of that into account in your quote.
Asking for a quote
To make quoting easier, let us know:
- Any access issues, like height or stairs
- The type of property
- What the problem is, such as mould, gaps, leaks or cracking
- Where the property is
Quotes start with a quick conversation. Describe the problem, the location and the size of the job, and we will explain how we’d tackle it. When it suits you, phone 0345 464 0079 or email us.
Leave it or put it right?
If you are painting or rendering, reseal at the same time. A clean new bead makes new paint or render look finished, and it’s easier while the walls are being worked on anyway. Older cottages and farmhouses around Southfleet can have timber floors and frames, and water through a failed joint can rot timber if it’s left.
Every job is a little different, so each one gets its own quote. The number of joints, how easy they are to reach and the sealant needed all make a difference.
Why book with us
- Rated 4.9 stars on Google
- Sanitary silicone with an anti-fungal additive in wet areas
- Colour agreed with you before work begins
- Homes, businesses and hotels
Read how sealant jobs are priced and customer reviews.
Nearby places to Southfleet
More services for Southfleet
Windows and doors in Southfleet
Compared with the north and west, the South East gets less rain, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind. Historic houses like Cobham College (about 3.6 miles south-east) are a reminder that the area around Southfleet has older buildings as well as new. In older buildings, older timber frames in brick or stone need a different approach from a modern uPVC window.
Schools such as Sedley's Church of England Voluntary Aided Primary School are buildings too, and larger buildings have plenty of frames, and the mastic around each one ages. For an older house near a landmark such as Church of St Nicholas, frames set in older brick or stone need a sealant that suits the wall as well as the frame.
Southfleet is about 2 miles south-west of Northfleet, in Kent. From the centre of Southfleet to the outskirts, window mastic is available for homes and businesses alike. Across Kent, we cover 922 places, and Southfleet is one of them. We also work in London, about 19 miles from Southfleet.
We work across the DA13 postcode area for window mastic. If you need window mastic at a property on Red Street, Gloxinia Road and Brakefield Road or anywhere close by, we can help. Other places close to Southfleet include Hook Green (1 mile south-west), Northfleet Green (1 mile east), Betsham (1 mile north-west), Painters Ash (1 mile north-east) and Springhead (1 mile north). Larger places within reach include Maidstone (13 miles south-east), Dartford (5 miles north-west), Sevenoaks (11 miles south-west), Gravesend (3 miles north-east), Tonbridge (15 miles south) and Swanley (7 miles west).
What’s near Southfleet
We work in homes and buildings around Northfleet School for Girls, Black Lion pub and Longfield Chalk Bank. The nearest railway station is Longfield station, roughly 1.5 miles south-west of the centre. Other landmarks nearby include Gravesham Community Hospital (2.7 miles north-east) and Bluewater (2.9 miles north-west). Not far away are Sawyers Lake.
How the job changes by surface
uPVC windows
uPVC expands and contracts noticeably with temperature, so we use a flexible, low-modulus sealant. White is the usual colour, with brown, anthracite grey and black for coloured frames.
Patio & French doors
Heavy door frames can move more than windows. A flexible sealant copes with that, where a rigid one would crack.
Do you need window mastic in Southfleet?
Plenty of failed mastic was poorly applied in the first place. Mastic laid onto dusty, damp or crumbling surfaces never bonded as it should, so it comes away long before its time.
Any of these means the joints need attention:
- A bead that doesn’t match the frame
- Whistling draughts around closed windows
- Leaking joints at the ends of sills
- Black, perished sealant on frames
If you let a flat or house near Longfield station, sound mastic around windows and doors keeps out the draughts and damp that tenants notice first.
Before you book anyone
- What guarantee comes with the work
- Who does the work, and how experienced they are
- Whether they seal over old material or remove it
- What the cure time is
Southfleet questions
Can you do window mastic in Southfleet?
Yes. Our work covers London and the South East, and Southfleet is part of that. You can ring 0345 464 0079 or email us and let us know what needs doing, and we will give you a clear quote.
Is Southfleet within the area you cover?
Yes, Southfleet is covered. We work across London and the South East, from towns to the smallest places. The journey is planned ahead, so it helps to know about access.
Can you work on commercial sites?
Yes. Hotels, offices and other businesses use us, and we are fully insured.
Will resealing my frames help with draughts?
In many cases. Air often gets in between the frame and the wall, and resealing inside and out closes it.
Do I need to be at home?
We need access to the joints, so we will agree that with you when we book. Indoors, that generally means someone at home.
Where are you based?
We’re a Crawley-based firm, with over 20 years’ experience. We work across South East England, London and Scotland.
Can landlords and businesses book you?
Yes, regularly. We can quote for several properties at once, and between tenancies is a good time for the work.
Is the new sealant paintable?
Not if it’s silicone. Tell us your decorating plans and we will pick a sealant to suit.
Keeping the joints in good condition
No joint lasts for ever, but care makes a real difference. A few tips:
- Air rooms to keep condensation down around windows
- Keep paint and stain on wooden frames in good order
- Avoid harsh chemicals near the mastic
- Look round the frames every year or so
Keep the new mastic undisturbed while it cures, for as long as we advise. Do not point a pressure washer at the joints.
Water gets in quietly when mastic fails. You might not see it until plaster blows or a damp patch appears inside. Early resealing stops it reaching that point.
DIY versus a professional finish
If you are set on DIY, put the effort into preparation: take out all the old sealant, make sure the joint is clean and dry, and give it the full cure time. If it doesn’t work out, we can still put it right.
If you’ve already had a go yourself, that’s fine. We cut it out and start again.