Portsmouth · England
External & façade joints in North End, Portsmouth
Professional external mastic in and around North End, with old sealant always removed completely.
- Water getting into walls through failed joints
- Joints pointed up with cement by mistake
- Old sealant gone brittle and cracked
How we handle external mastic in North End
A movement joint is a deliberate break that lets a wall expand and contract. Its sealant has to flex with the building, season after season, so once it splits or hardens, the joint stops working and water gets in. We work on concrete & block, façade panels and brickwork movement joints, and people most often call us about brick movement joints where the sealant has split and weeds or debris growing in open joints.
Around North End, garages, outbuildings and extensions all add to the joints on the outside of a home. Gutter ends, garage door frames and the joints where an extension meets the house are typical spots for leaks.
We stand behind the work with a 12-month guarantee, so you’re covered after we’ve gone.
- Where
- North End (PO2, PO1)
- Wider area
- Portsmouth
- Guarantee
- 12 months on all our work
- Quote
- Quoted before any work starts
- Call
- 0345 464 0079
- Last updated
- 26 October 2026
Should I try it myself first?
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.
The biggest DIY mistake is sealing over old sealant. Silicone does not stick to old silicone, so it peels away and traps moisture behind it. Everything old must be removed first.
What happens on the day
On the day, there’s very little for you to do. Show us the job and we’ll take it from there. The job generally takes a few hours for a handful of joints, longer for a whole elevation, including the tidy-up. In a smaller place like North End, 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 inspect the joints and agree which need resealing and how they’ll be reached.
- The old mastic and anything lodged in the joint is removed.
- We clean both faces of the joint and prime them where the product calls for it.
- We push in closed-cell backing rod so the sealant is the right depth and bonds to the sides only.
- The new sealant, chosen to suit the brick or render, is applied and tooled to a neat finish.
Before we arrive
- On commercial sites, let us know about site rules
- Tell us about any water getting in
- Let us know about stairs, lifts or work at height
Ask for a quote
To get a quote, phone 0345 464 0079 or email us and tell us where the job is and what the problem looks like. You’ll have a clear quote before any work starts.
Advice
Why deal with it now?
It often makes sense to reseal all the failing joints on an elevation together. They’ve weathered the same way, and access only has to be arranged once. In an older home around North End, damp from a failed joint can get into timber and plaster, which is far harder to put right than the sealant itself.
The cost reflects the work involved, not a rough estimate. That’s why we ask a few questions first and agree the price before starting.
Why North End clients choose us
- An ARBOMaster approved applicator
- A sealant colour to suit the surroundings
- White, clear, grey or coloured to suit, where the product allows
- A 12-month guarantee on all work
Take a look at what affects the cost and our reviews.
What we can’t put right
In fairness, there are a few things sealant will not fix:
- Structural movement, which needs a surveyor or engineer
- Damp that isn’t coming from the joint
- Adding movement joints to masonry that has none
Not sure which it is? You can call 0345 464 0079 or send us an email and we’ll tell you honestly before you book.
Where we work in North End
- Concrete & block
- Façade panels
- Copings & trims
- Render & cladding joints
- Brickwork movement joints
- Joints between brick and frames
North End: your questions answered
Is North End within the area you cover?
Yes, North End is covered. Our work covers London and the South East, from towns to the smallest places. Longer journeys are simply planned in advance.
Can you help a landlord with a rental near Hilsea station?
Yes, rental work is part of what we do. Just ring 0345 464 0079 or drop us an email and tell us about the property, and we’ll give you a clear price.
Can you seal joints between render and window frames?
Yes. We cut out the old sealant, prepare both faces and reseal with a flexible exterior product. The colour is chosen to suit.
How long does the job take?
It depends on the size of the job, but most jobs take a few hours for a handful of joints, longer for a whole elevation. We will tell you when we quote.
How do I get a quote for external mastic in North End?
It depends on the job, so we quote each one individually. To get one, phone 0345 464 0079 or send us an email and tell us what needs doing and where.
Can you do several jobs on one visit?
Yes, and it often makes sense. Doing several areas at once is generally more efficient, so mention them when you ask for a quote.
Are you an approved applicator?
Yes. We’re approved under the ARBOMaster scheme, which is run for the Arbo sealant brand.
Which products do you use?
The product depends on the job: sanitary silicone where it gets wet, and sealants suited to movement or weather elsewhere. We use products from Arbo and Everbuild.
More services for North End
How to look after the new joints
Looking after new joints is easy:
- Keep soil, plants and ivy away from the joints
- Ask before painting over external sealant
- Make sure movement joints are not pointed over
- Have failed joints looked at early
Have a quick look at the joints each spring. Splits, gaps at the edges or plants in the joint are early warning signs.
Leaks behind façade panels and render often go unseen. By the time there’s a damp patch, the damage can be well established, so it’s worth resealing at the first signs.
Signs you need external mastic in North End
Poor preparation causes many early failures: dusty or wet faces, no primer where one was needed, or old sealant left in. The sealant never bonds properly.
Any of these means the joints need attention:
- Hard, crazed mastic that has stopped moving
- Movement joints filled with mortar instead of sealant
- Sealant pulling away from one side of the joint
- Moss and dirt in joints with no sealant left
If you let a flat or house near Hilsea station, outside joints that have cracked can let damp into a rental, so check them between lets.
Comparing quotes
- Which sealant they’ll use, and why
- Is the old sealant removed completely?
- How long to leave it before use
- What the quote includes, VAT included or not
Outside joints around North End
North End is within about 1 mile 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 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, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
For an older house near a landmark such as St. Mark’s, the joints between older walls, newer extensions and the roofline need a sealant that can move. Managing a site like Corpus Christi Catholic Primary School? Then its movement joints, gutters and trims need looking after like any other building’s.
North End is about 1 mile north of Portsmouth, in Portsmouth. If you need external mastic in North End, please ring 0345 464 0079 or drop us an email for a quick quote. We cover Portsmouth from our Crawley base. Our Portsmouth coverage runs to 19 places, North End among them.
Every address in PO2 and PO1 is within our area for external mastic. Whether your property is on Knox Road, Croft Road and Kirby Road or anywhere close by, our applicators can take on the job. Main roads around North End include the A2047, which makes travel easy. Close by, we work in Rudmore (1 mile south-west), Tipner (1 mile west), Portsmouth (1 mile south), Copnor (1 mile south-east) and Hilsea (1 mile north-east).
What’s near North End
In North End, that means homes and buildings near Mayfield School, Alexandra Park and St Edmund's Catholic School. The closest station to North End is Hilsea station, about 1.2 miles north-east of the centre. A little further out are Charles Dickens Birthplace Museum (0.8 miles south-west) and Portchester Castle (2.1 miles north-west). The countryside around North End includes Portsdown Hill and Milton Locks.
What affects the cost of external mastic
The quote reflects the job in front of us. We look at:
- Access and height
- Whether old sealant or filler has to be cut out
- How much there is to do
- How many rooms, windows or areas are involved
Some things make a job bigger or smaller: how much old sealant there is and how stubborn it is, whether mould needs treating, and whether the work is at height. We take all of that into account in your quote.
What we need to know
The more you tell us, the more accurate the quote. When you ask for a quote, tell us:
- Any access issues, like height or stairs
- The problem you’ve noticed
- Pictures of the joints, sent by email
- Where the property is
We quote each job on its own. Simply call 0345 464 0079 or send us an email and describe the job, and pictures are welcome.