Hampshire · England
Blackfield External Mastic
Our applicators work in Blackfield on sealing brickwork movement joints, render, cladding and façade joints. Old sealant removed completely, joints prepared properly.
- Old sealant gone brittle and cracked
- Rain getting behind render or cladding at a joint
- Panel joints letting water in
How we handle external mastic in Blackfield
Joints in render and cladding are easy to overlook until a damp patch appears. We look over the joints, agree the ones to renew and reseal with a flexible, weatherproof product. We work on copings & trims, concrete & block and brickwork movement joints, and the jobs we see most are water getting into walls through failed joints and weeds or debris growing in open joints.
In and around Blackfield, older properties sit alongside newer ones, each with its own outside joints. Older gutters and trims need their joints resealed; newer brick and render need their movement joints kept sound.
You are covered for a year from the day we finish. If anything is not right with it, call 0345 464 0079 or email us.
- Place
- Blackfield (SO45)
- Region
- Hampshire
- Cover
- A year, on every job
- Quotes
- A clear price before we start
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
What happens on the day
All our tools and materials come with us in the van. Once we’ve agreed what’s being done, we protect the area and start. It normally takes a few hours to a few days, depending on the length of joint and the access. In a smaller place like Blackfield, 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 start by checking each joint, agreeing the ones to redo and how we will reach them.
- We cut out the failed sealant and rake out any dirt or growth.
- Both sides are cleaned back to sound material and primed if needed.
- 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.
Preparing for the visit
- Clear items away from the joints we’re working on
- Tell us about any previous sealing or DIY attempts
- For indoor joints, keep the area dry beforehand if you can
Get a quote
Call for a quick quote, or email us if that is easier. Describe what needs sealing and we will talk you through the work.
Read more
What external mastic looks like in Blackfield
Blackfield is close to the coast, and homes near the sea take more wind-driven rain, with salt in the air closer to the shore. That’s hard on movement joints and outside wall joints, especially on the side facing the sea. Historic houses like Beaulieu Palace House (about 3.6 miles west) are a reminder that the area around Blackfield has older buildings as well as new. In older buildings, older brick and stone need a sealant that suits them, at the right joint depth.
Rented homes near Hamble station change hands often, and failed wall and movement joints let damp in, so they’re worth checking between tenancies. For an older house near a landmark such as St Francis, the joints between older walls, newer extensions and the roofline need a sealant that can move.
Blackfield is about 3 miles south-east of Hythe, in Hampshire. Homes, rented property, offices and hotels in Blackfield is covered for external mastic. The work is guaranteed for a year. We cover 683 towns and villages across Hampshire. You can also see our page for Southampton, roughly 7 miles from Blackfield.
We work across the SO45 postcode area for external mastic and the streets around it. If you need external mastic at a property on Newlands Copse, St Michaels Close and Dark Lane or anywhere close by, our applicators can take on the job. Other places close to Blackfield include Langley (1 mile south), Roughdown (1 mile west), Holbury (1 mile north-west), Fawley (1 mile north-east) and Stonehills (1 mile north-east). Further out, we also cover Gosport (9 miles east), Eastleigh (10 miles north), Fareham (8 miles east), Totton (9 miles north-west), Chandler's Ford (12 miles north) and Hedge End (7 miles north-east).
What’s near Blackfield
In Blackfield, that means homes and buildings near The New Forest Academy and Church of All Saints and the streets around them. For rail, the closest station is Hamble station, roughly 4.1 miles north-east. A little further out are Beaulieu Abbey And Display Of Monastic Life (3.8 miles west) and Coldeast (5.2 miles north-east). Not far away are Mercury Marshes.
Do you need external mastic in Blackfield?
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:
- Plants rooting in failed movement joints
- Hard, crazed mastic that has stopped moving
- Movement joints filled with mortar instead of sealant
- Movement joints with cracked, split or missing sealant
Managing a site like Blackfield Primary School? Then larger buildings have long runs of movement joint that eventually need resealing.
What to look for in a quote
- When the joint can take water or movement
- Whether the sealant suits the joint
- What preparation is included
- Which colour the sealant will be
Honest limits
Before you book, it’s worth knowing the limits:
- Cracking across the wall rather than at a joint
- Structural movement, which needs a surveyor or engineer
- Walls that need new movement joints cut into them
If in doubt, phone 0345 464 0079 or drop us an email and we will say what we think before booking.
Joints and surfaces we work on
- Copings & trims
- Brickwork movement joints
- Render & cladding joints
- Joints between brick and frames
- Concrete & block
- Façade panels
How we quote for external mastic
The quote reflects the job in front of us. We take into account:
- Which sealant suits the joint
- How much old sealant there is and how hard it is to remove
- Whether there’s mould to deal with
- The amount of work
Homes and businesses are quoted the same way: how much there is to do, how we reach it and what it needs, along with when we can work on site. Call for a quick quote and we’ll explain what it covers.
Asking for a quote
You don’t need to know the technical terms. It helps if you can tell us:
- What the problem is, such as mould, gaps, leaks or cracking
- Whether it’s a home or a business
- How many joints, rooms or windows are involved
- Where the job is, and your postcode
We do not publish a price list. Instead, your job gets its own clear quote. To get started, call 0345 464 0079 or email us.
Why deal with it now?
An open joint keeps letting water into the wall with every downpour. In cold weather, frost can damage wet brick and render around the joint, so the problem grows beyond the joint itself. Around Blackfield, water from a failed joint in an older home can soak 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 about the job first and agree the price before starting.
Why Blackfield clients choose us
- We’re fully insured
- Sanitary silicone with an anti-fungal additive in wet areas
- Quality sealants from Arbo and Everbuild
- 180+ five-star Google reviews
Read what affects the cost or customer reviews.
Different surfaces, different methods
Copings and trims
Coping and trim joints face rain and sun head on. Each is resealed with a weatherproof, flexible sealant.
Joints between dissimilar materials
Brick against render, concrete against metal, stone against timber: every change of material is a joint. We seal the joint with a flexible exterior sealant so the movement is taken up.
Common questions in Blackfield
Does living near the coast affect external mastic in Blackfield?
Coastal homes put outside sealant through more weather than inland ones, so the choice of sealant and the preparation matter even more. It’s worth checking the walls that face the sea first.
Do you work for landlords with property near Hamble station?
Yes, rental work is part of what we do. Just ring 0345 464 0079 or email us and tell us about the property, and we’ll send you a clear quote.
Does someone need to be in?
For indoor joints, yes, someone needs to let us in. After that, you can carry on with your day.
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.
Can I do it myself?
That depends on the joint. High-level, external movement and fire-rated joints are professional jobs.
Do you come to Blackfield?
Yes. From our base in Crawley, we cover South East England, London and all of Scotland.
What do you put in the joint?
Each joint gets the product that suits it. Movement, water and weather all affect the choice.
What colours does the sealant come in?
The sealant colour is picked to suit the wall so the joint blends in. There’s a wide choice of exterior colours.
Places near Blackfield
More services for Blackfield
DIY sealant or a professional job?
Some sealant jobs are within reach of a careful DIYer, like a short, easy-to-reach joint indoors. The common mistakes are sealing over old sealant, sealing a damp joint and using far too much.
Sealing over old silicone is the commonest DIY error. Silicone doesn’t stick to old silicone, so it peels away and traps moisture behind it. All the old material has to come out first.