Portsmouth · England
External & façade joints in Copnor, Portsmouth
External mastic in Copnor from a team with over 20 years’ experience. 180+ five-star Google reviews and a 4.9 rating.
- Cracked joints where brick meets render or frames
- Old sealant gone brittle and cracked
- Weeds or debris growing in open joints
External mastic in Copnor: local notes
Copnor is close to the coast, where wind-driven rain is a fact of life and, nearer the shore, so is salt air. That’s hard on movement joints and outside wall joints, especially on the side facing the sea. Rainfall in the South East is lower than in much of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
If you let a flat or house near Fratton station, failed wall and movement joints let damp in, so they’re worth checking between tenancies. Managing a site like Westover Primary School? Then larger buildings have long runs of movement joint that eventually need resealing.
Copnor is about 1 mile east of Portsmouth, in Portsmouth. Whether you are in the middle of Copnor or further out, we cover external mastic for every kind of property. We cover 19 towns and villages across Portsmouth.
We cover every part of PO3, PO2 and PO1 for external mastic and the streets around it. You will find streets such as New Road, Lynn Road and Byron Road, all of which we cover. Main roads around Copnor include the A288. Other places close to Copnor include Baffins (1 mile south-east), Kingston (1 mile south), Portsmouth (1 mile west), Fratton (1 mile south-west) and North End (1 mile north-west).
Around Copnor
Around Copnor, our work takes us to homes and buildings near The Jolly Taxpayer pub, Alexandra Park and St Edmund's Catholic School. Copnor’s nearest station is Fratton station, about 1.1 miles south-west of the centre. Nearby you’ll also find The Bridge Shopping Centre (1.1 miles south-west) and St Mary's Hospital (0.7 miles south). The countryside around Copnor includes Milton Locks and Portsdown Hill.
External mastic in Copnor
Getting the depth right is half the job. Closed-cell backing rod sets the depth and stops the sealant sticking to the back, leaving it bonded to two faces so it can move with the wall. If you’re dealing with plants rooting in failed movement joints and gaps where render, brick and frames meet, we can help, on brickwork movement joints, façade panels and joints between brick and frames alike.
In a smaller place like Copnor, some homes face open ground, and walls and rooflines facing the weather take the worst of it. Joints on those sides are normally the first to go.
You get a 12-month guarantee, the same in Copnor as everywhere else we work.
- Location
- Copnor (PO3, PO2, PO1)
- Region
- Portsmouth
- Guarantee
- One year on every job
- Quote
- A clear price before we start
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
Other services in Copnor
Why act early in Copnor
A failed movement joint lets water into the wall and can run behind render or cladding. Resealing early keeps the job to the joint itself, rather than the wall around it. Homes in smaller places like Copnor can face more weather, and failed outside joints let damp into walls. Indoors, a failed seal lets water into floors and panels as it would anywhere.
No two jobs are quite the same, so we quote each one individually. The number of joints, how easy they are to reach and the sealant needed all make a difference.
Why Copnor customers choose us
- We agree the colour with you first
- Any old sealant cut out fully, not covered over
- ARBOMaster approved applicator
- A choice of colours where the product allows
See what affects the cost and what customers say.
How to look after the new joints
To keep the joints looking good and working properly:
- Deal with leaking gutters that soak the joints below
- Get split or bare joints resealed while the damage is small
- Check the sealant is paintable before painting near it
- Walk round the building once a year and look at the joints
Look over the joints once a year, ideally after winter. Splits, gaps at the edges or plants in the joint are early warning signs.
Gaps, plants or missing sealant in a joint are worth getting looked at. Early work is quicker and leaves a better finish.
What we do, step by step
Once we’re on site, we compare the joints with what we discussed. If anything is different, we explain it before carrying on. After that, the work takes anything from a few hours to several days, depending on the building. Parking around Copnor is generally easier than in a town centre, but mention any lanes, gates or long drives. If the job is outside, tell us about side access and how high the joints are.
- We start by checking each joint, agreeing the ones to redo and how we’ll reach them.
- We cut out the failed sealant and rake out any dirt or growth.
- 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.
- The new sealant, chosen to suit the brick or render, is applied and tooled to a neat finish.
How to prepare
- On commercial sites, let us know about site rules
- Let us know about stairs, lifts or work at height
- Tell us about any water getting in
Getting 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.
Related advice
What the job involves on each surface
Cladding and façade panels
If the façade has a specified sealant, that is what we use or an approved alternative. Send us any details you have about the façade.
Concrete and blockwork
Concrete and block walls shrink as they dry and move with temperature. We reseal their joints with backing rod and a flexible product.
What we are called out for in Copnor
Joints sealed without backing rod, or far too deep, rarely last. If the sealant sticks to the back as well as the sides, it cannot stretch and rips as the joint opens.
Look out for any of the following:
- Movement joints filled with mortar instead of sealant
- Weeds or debris growing in open joints
- Joints with sealant missing in places
- Sealant pulling away from one side of the joint
Homes close to Church of St Alban include some older properties, and old and new materials meet at the roofline and walls, which is where sealant earns its keep.
Before booking anyone
- When the joint can take water or movement
- How the colour is chosen
- How hidden problems are handled
- Whether they seal over old material or remove it
Common questions in Copnor
Is Copnor within the area you cover?
Yes, smaller places are covered as well as towns. Our work covers London and the South East. Let us know about access, parking and anything unusual about getting there when you book.
Is external mastic in a coastal place like Copnor any different?
Near the coast, wind-driven rain and, nearer the shore, salt air make outside sealant work harder. Choosing the right sealant for the frame and wall, laid at the right depth, helps it last.
I’m a tenant. Can you help?
Yes. Ask your landlord first, and we can send them the quote if that helps.
Is the work guaranteed?
Yes. Every job comes with our one-year guarantee.
What information do you need?
Just the basics: the address or postcode, what’s wrong and any access issues. Then ring 0345 464 0079 or email us.
Are you ARBOMaster approved?
Yes. We’re an ARBOMaster approved applicator, which is run for the Arbo sealant brand.
Do you work at height?
It depends on the height and the site. Low-level joints are straightforward; for higher ones, send details and we’ll confirm the access.
Will it make a mess?
Not at all. The area is protected while we work and cleaned up afterwards.
Landlords, agents and businesses in Copnor
A neglected joint can let water reach the structure, which is a bigger problem in a rented property. Resealing at the right time is simple maintenance that we can handle for you.
Businesses can book us for washrooms, kitchens, offices and more. For commercial premises, we can talk through working times when we quote.
What we can’t put right
Sealant is not the answer to every problem, and we’d rather say so up front. Sealant will not put right:
- Damp that is not coming from the joint
- Render that is blown, hollow or coming away
- Cracked brickwork or render that needs a builder or plasterer
Not sure which it is? You can ring 0345 464 0079 or email us and we’ll tell you honestly before booking.
What we seal
- Brickwork movement joints
- Concrete & block
- Façade panels
- Copings & trims
- Render & cladding joints
- Joints between brick and frames