Medway · England
External Mastic in Upper Upnor
External mastic across Upper Upnor and nearby, with every bit of old sealant taken out first and a 12-month guarantee.
- Gaps where render, brick and frames meet
- Panel joints letting water in
- Joints pointed up with cement by mistake
Questions from Upper Upnor
Will you come out to Upper Upnor?
Yes, we do. Our work covers London and the South East, and smaller places are part of that. The journey is planned ahead, so it helps to know about access.
Does living near the coast affect external mastic in Upper Upnor?
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.
Can I do it myself?
For a simple, easy-to-reach joint, a careful DIYer can do a reasonable job. Most DIY failures come from sealing over old material, wet joints or too much sealant.
What is a movement joint?
Brickwork, render and cladding all move a little, and planned joints take up that movement. The gap is sealed with a flexible sealant over backing rod.
Do you hold any approvals?
Yes. We hold ARBOMaster approved applicator status, and we’re fully insured.
Will there be a smell?
Some sealants have a smell while they cure, but it fades. Ventilation helps.
Is the work guaranteed?
Yes, for a year. If anything isn’t right with the work within the year, let us know and we’ll sort it.
Can you seal over the old sealant?
No. The old sealant always comes out first.
External mastic for homes and businesses in Upper Upnor
We cut out failed sealant, set the joint depth with closed-cell backing rod and reseal with a low-modulus exterior sealant. We pick a colour that sits well with the wall so the joint does not stand out. Common call-outs are for panel joints letting water in and joints with sealant missing in places, across façade panels, copings & trims and render & cladding joints.
Around Upper Upnor, older buildings can be stone, brick or timber-framed, many with extensions added later. Where one material meets another is where water generally gets in, and they need the right sealant at the right depth.
Whatever the size of the job, you get the same 12-month guarantee in Upper Upnor and across Medway.
- Where
- Upper Upnor (ME2)
- Region
- Medway
- Guarantee
- A year, on every job
- Price
- A clear quote up front
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
Common problems we fix in Upper Upnor
Weeds, moss and debris in a joint are a sign the sealant has gone. Roots and dirt hold water against the wall and make things worse.
Keep an eye out for these signs:
- Moss and dirt in joints with no sealant left
- Leaking joints around cladding and façade panels
- Joints pointed up with cement by mistake
- Joints with sealant missing in places
In the older streets around St Philip & St James, old and new materials meet at the roofline and walls, which is where sealant earns its keep.
What your quote should include
- Is the old sealant removed completely?
- What guarantee comes with the work
- What happens if they find a problem under the old sealant
- Are they insured?
Walls and rooflines in Upper Upnor
Upper Upnor is within about 2 miles of the coast, where wind-driven rain is a fact of life and, nearer the shore, so is salt air. Both are hard on movement joints and outside wall joints, which can dry out and crack sooner where a building faces the weather. 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.
Rented homes near Strood station change hands often, and failed wall and movement joints let damp in, so they’re worth checking between tenancies. Schools such as Wainscott Primary School are buildings too, and larger buildings have long runs of movement joint that eventually need resealing.
Upper Upnor is about 2 miles north-east of Rochester, in Medway. If you need external mastic in Upper Upnor, please phone 0345 464 0079 or drop us an email for a quick quote. We are based in Crawley and cover Medway. We cover 68 towns and villages across Medway, from the larger towns to small villages. Our Chelmsford page covers work nearby (23 miles or so).
We work across ME2 for external mastic and the streets around it. We cover properties on High Street, Upnor Road and Castle Street. We also cover Lower Upnor (1 mile north-east), Wainscott (1 mile north-west), Chattenden (1 mile north), Hoo St Werburgh (2 miles north-east) and Cooling Street (3 miles north). Larger places within reach include Gillingham (3 miles south-east), Chatham (3 miles south), Rainham (5 miles south-east), Luton (3 miles south), Park Wood (5 miles south-east) and Lordswood (5 miles south).
Landmarks near Upper Upnor
Typical jobs here are in homes near The Kings Arms, Lower Lines Park and Waterfront University Technical College and the streets around them. Also close by are Former Ordnance Store At Chatham Gun Wharf (1.4 miles south) and Waterfront UTC (1.3 miles south-east). For rail, the closest station is Strood station, about 1.2 miles south-west. Other landmarks nearby include French Hospital (1.5 miles south-west) and Pentagon Shopping Centre (1.6 miles south). Open spaces near Upper Upnor include Gad's Hill and Rede Common.
Landlords, agents and businesses in Upper Upnor
Mouldy or split sealant often shows up at the end of a tenancy, and it’s easy to sort out between tenants. Several properties can go on one quote.
We also work for businesses, from offices to washrooms and kitchens. For commercial premises, we can talk through working times when we quote.
Towns and villages near Upper Upnor
Also in Upper Upnor
The process
You don’t need to clear the whole room or building before we come, only the area right around the joints. Everything nearby is protected, and the job takes anything from a few hours to several days, depending on the building for a typical job. In a small place like Upper Upnor, access is usually the main thing to plan. If the job is outside, mention outbuildings, exposed walls and how to reach them.
- We start by checking each joint, agreeing the ones to redo and how we’ll reach them.
- Old sealant and any debris are cut and raked out.
- We clean both faces of the joint and prime them where the product calls for it.
- Backing rod goes in next, setting the depth and keeping the sealant off the back of the joint.
- A flexible exterior sealant is applied and tooled in a colour to suit the wall.
How to prepare
- Tell us if parking is tricky
- For indoor joints, keep the area dry beforehand if you can
- Let us know about stairs, lifts or work at height
Get a quote
For a quote, phone 0345 464 0079 or send us an email and tell us where the job is and what the problem looks like. You’ll have a clear quote before work begins.
Advice
DIY sealant or a professional job?
Some jobs are best left to a professional: high-level joints, fire-rated gaps, external movement joints and big jobs call for the right materials, safe access and experience.
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 fails, we can still redo it.
Keeping the joints in good condition
No joint lasts for ever, but care makes a real difference. Our tips:
- Check the sealant is paintable before painting near it
- Deal with leaking gutters that soak the joints below
- Walk round the building once a year and look at the joints
- Make sure movement joints are not pointed over
Make sure anyone working on the wall later knows where the movement joints are. They must stay as flexible joints, never rendered or pointed over.
An open movement joint lets rain into the wall every time it pours. That can lead to damp patches, staining and frost damage, all bigger jobs than a reseal.
What we can’t put right
We’d rather tell you now than do work that will not last, so these are the limits:
- Adding movement joints to masonry that has none
- Damp from another source, such as a leaking gutter or a bridged damp-proof course
- Cracking across the wall rather than at a joint
If in doubt, call 0345 464 0079 or email us and we’ll say what we think before you book.
What we seal
- Façade panels
- Brickwork movement joints
- Concrete & block
- Joints between brick and frames
- Render & cladding joints
- Copings & trims
Leave it or put it right?
A failed movement joint lets water into the wall. Resealing early keeps the job to the joint itself, instead of the wall and finishes around it. Around Upper Upnor, older homes often have timber in their floors and frames, where water from a failed joint can cause rot if it’s left.
Leaving a failed joint normally makes the job bigger, not smaller, as water and mould keep getting in. If you’re unsure, phone 0345 464 0079 or email us and we will give you an honest view and a quote.
Why choose Mr Mastic in Upper Upnor
- 12-month guarantee on every job
- More than 20 years in sealant work
- 180+ five-star Google reviews
- Quality sealants from Arbo and Everbuild
Take a look at how sealant jobs are priced and customer reviews.