Medway · England
Window Mastic in Lower Upnor
Professional window mastic in and around Lower Upnor, with every bit of old sealant taken out first and a 12-month guarantee.
- Damp patches on the reveal after heavy rain
- Mastic that has split away from the wall
- Draughts coming in around windows and doors
How it works
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. After that, the work takes a few hours for a few frames, or a day or more for a whole house. For a village or hamlet like Lower Upnor, the journey is planned in advance: tell us about narrow lanes, gates, long drives and where we can park. Everything for the job comes with us, so a second trip is avoided where possible.
- First we look at every frame and agree the list.
- Next the failed sealant is cut away and the joint cleaned.
- We fit backing rod in deep gaps so the sealant is the right depth.
- A flexible, weatherproof sealant is applied in a colour to suit the frame.
- Finally we tidy up and check each joint.
Before we arrive
- Plan for the work area to be out of bounds to pets and children
- Mention any leaks or damp you’ve noticed
- Clear the area around the work
How to get a quote
Quotes start with a quick conversation. Tell us what’s wrong, where it is and how much there is, and we will talk you through what we’d do. Whenever you are ready, phone 0345 464 0079 or send us an email.
Advice
Window mastic in Lower Upnor, done properly
Mr Mastic’s applicators have more than 20 years’ experience with window and door sealants. We’re fully insured ARBOMaster approved applicators, and every job is covered by a 12-month guarantee. We work on aluminium frames, timber windows & doors and composite doors, and people most often call us about draughts coming in around windows and doors and rain getting in at the frame or under the sill.
Outdoor sealant needs dry, clean surfaces, so work on frames around Lower Upnor is planned for dry weather. Tell us about access to every side of the house, including upper-floor windows.
We guarantee the work for a year. If there’s a problem with our work within the year, let us know and we will sort it.
- Where
- Lower Upnor (ME2)
- Wider area
- Medway
- Cover
- 12 months on all our work
- Price
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
Lower Upnor homes and the weather
Lower Upnor is within about 2 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 window and door frames, which can dry out and crack sooner where a building faces the weather. The South East is one of the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
For landlords with property near Strood station, cracked frame mastic tends to show up as a draught or damp complaint, so it’s worth checking between lets. Schools such as Chattenden Primary School are buildings too, and larger buildings have plenty of frames, and the mastic around each one ages.
Lower Upnor is about 2 miles north-east of Rochester, in Medway. If you need window mastic in Lower Upnor, please call 0345 464 0079 or drop us an email for a quick quote. We are based in Crawley and cover Medway, Lower Upnor included. Our area takes in 68 places across Medway, from the larger towns to small villages. You can also see our page for Chelmsford, roughly 23 miles from Lower Upnor.
Here we cover the ME2 postcode area for window mastic. Window mastic is available to properties on Galleon Way, Cutter Close and Schooner Walk. We also cover the places around Lower Upnor: Upper Upnor (1 mile south-west), Chattenden (1 mile north), Wainscott (1 mile west), Hoo St Werburgh (2 miles north-east) and Cooling Street (2 miles north). Larger places within reach include Gillingham (3 miles south-east), Chatham (4 miles south), Rainham (5 miles south-east), Strood (3 miles south-west), Luton (3 miles south) and Park Wood (5 miles south-east).
What’s near Lower Upnor
Around Lower Upnor, our work takes us to homes and buildings near Former Ordnance Store At Chatham Gun Wharf, The Hundred of Hoo Academy and Waterfront University Technical College, among other places. You’ll also find Lower Lines Park (1.3 miles south-east) and The Ship pub (under half a mile east). The nearest railway station is Strood station, about 1.6 miles south-west of the centre. Nearby you will also find Upnor Castle (less than half a mile south) and Pentagon Shopping Centre (1.9 miles south). Not far away are Rede Common and Gad's Hill.
Work for landlords, hotels and businesses
From a single let to a portfolio, the work is the same standard: old sealant fully removed, joints prepared properly and a one-year guarantee.
If you manage several properties in or around Lower Upnor, several properties can be quoted together. Send us the addresses and the work at each, and pictures by email help.
Looking after it afterwards
No joint lasts for ever, but care makes a real difference. Our tips:
- Don’t use solvent cleaners on the joint
- Avoid blasting the frames with a pressure washer
- Paint up to the joint, not over it
- Clear any debris from frame drain holes
Wipe the frames with soapy water when you clean the windows, and avoid solvent cleaners on the sealant.
Leaks usually show up in wet, windy weather, but sealant goes on best when frames and walls are dry. Sorting cracked mastic early means the joint is sound before the bad weather.
Can I do it myself?
Some jobs are best left to a professional: high-level joints, fire-rated gaps, external movement joints and big jobs need the right product, the right access and the right method.
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.
Different surfaces, different methods
Window sills
Stone and concrete sills have their own joints, including the one between the sill and the frame above. Those are sealed with a product suited to stone or concrete.
Composite doors
Front doors take the weather head on. Those corners get the most care.
What we are called out for in Lower Upnor
Sun, frost and rain wear sealant out. UV light hardens the outside of the bead, and over the years it loses its give, cracks and comes away.
The problems people generally mention when they call include:
- Gaps left after new windows were fitted
- Cracked internal joints between frame and plaster
- White mastic on grey or black frames
- Rain getting in at the frame or under the sill
In the older streets around St Philip & St James, the windows may be timber, sash or later replacements, and each needs the right sealant against the wall.
What to look for in a quote
- Whether you can choose the colour
- How long to leave it before use
- How much experience the applicator has
- What happens if the job turns out different
Questions from Lower Upnor
Do you cover smaller places like Lower Upnor?
Yes, smaller places are covered as well as towns. We work across London and the South East. Let us know about access, parking and anything unusual about getting there when you book.
Can you help a landlord with a rental near Strood station?
Yes. We work for landlords and letting agents as well as householders, and several properties can go on one quote. Just ring 0345 464 0079 or email us with the address and what needs doing, and we’ll give you a clear price.
Can you match the sealant to my frames?
Yes. White, brown, anthracite grey, black and clear sealants are all available, so the joint suits the frame.
Do you have insurance?
Yes. We’re fully insured for domestic and commercial work.
Does the work come with a guarantee?
Yes. Each job is covered for 12 months.
Can you seal the gap between the frame and the plaster indoors?
Yes. Plenty of draughts come through the inside joint as well as the outside, so sealing both is often worthwhile.
Does someone need to be in?
It depends on the job. For work indoors, someone needs to let us in, while outside work can sometimes be arranged differently.
How long will my window job take?
The work takes a few hours for a handful of frames, longer for a whole house. Access and how stubborn the old mastic is affect the time most.
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What we cannot put right
Honest advice matters more to us than a booking, so here’s what new sealant will not do:
- Faulty window hardware
- A door that needs adjusting, rehanging or new seals
- Misting between the panes of a double-glazed unit (that needs a new unit)
If in doubt, ring 0345 464 0079 or email us and we will say what we think before booking.
What we seal
- uPVC windows
- Timber windows & doors
- Composite doors
- Aluminium frames
- Patio & French doors
- Window sills