Hertfordshire · England
External Mastic in Mackerye End
External mastic across Mackerye End and nearby, with every bit of old sealant taken out first.
- Rigid filler in a joint that should flex
- Rain getting behind render or cladding at a joint
- Gaps where render, brick and frames meet
External mastic for homes and businesses in Mackerye End
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 line blends in. If you’re dealing with movement joints with cracked, split or missing sealant and water getting into walls through failed joints, we can help.
External sealant needs dry, clean surfaces, so work around Mackerye End is planned for dry weather. Let us know about access to every wall, plus any garages or outbuildings.
The work is guaranteed for twelve months. If something is not right with it in that time, tell us and we’ll put it right.
- Place
- Mackerye End (AL5)
- Region
- Hertfordshire
- Cover
- 12 months on all our work
- Price
- A clear price before work begins
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
What the job involves on each surface
Render joints
Render has movement joints and stop beads that need sealing. They’re resealed in a sealant that suits the render.
Brickwork movement joints
Brick walls have vertical movement joints to absorb expansion. They’re resealed over backing rod with a low-modulus sealant in a colour to suit the brick.
What affects the quote in Mackerye End
Jobs vary more than people expect. What affects the quote:
- Any working-time requirements on site
- The number and length of the joints
- Whether there’s mould to deal with
- The type of sealant required
Homes and businesses are quoted the same way: the amount of work, how we reach it and what it needs. Call for a quick quote and we’ll go through it with you.
Asking for a quote
To help us quote quickly, let us know:
- The rough size of the job
- Photos by email, if that’s easy
- Where the job is, and your postcode
- If someone has resealed it before
The more we know about the job, the more useful the quote. Let us know the location, the problem and roughly how many joints, and email photos if that’s easy.
What we cannot put right
In fairness, there are a few things sealant won’t fix:
- Cracking across the wall rather than at a joint
- Walls that need new movement joints cut into them
- Structural movement, which needs a surveyor or engineer
If in doubt, phone 0345 464 0079 or email us and we will say what we think before you book.
What we seal
- Joints between brick and frames
- Façade panels
- Copings & trims
- Concrete & block
- Brickwork movement joints
- Render & cladding joints
Why it’s worth doing now in Mackerye End
A properly done movement joint is an even line in a colour that suits the wall. A rushed bead with no backing looks untidy and does not last so it’s worth doing right. Around Mackerye End, 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 generally makes the job bigger, not smaller, as water and mould keep getting in. If you’re not sure whether it needs doing, phone 0345 464 0079 or email us for an honest opinion and a quote.
Why book with us
- We’re fully insured
- Anti-fungal sanitary silicone in wet areas
- White, clear, grey or coloured to suit, where the product allows
- Over 20 years’ experience
Take a look at how sealant jobs are priced or customer reviews.
When to call us in Mackerye End
Every building moves. Brickwork grows a little over the years, blockwork and concrete shrink, and all of it moves with heat and moisture. The sealant in the movement joints takes that strain.
Signs it’s time to call us include:
- Moss and dirt in joints with no sealant left
- Joints where the bead has come unstuck
- Panel joints letting water in
- Water getting into walls through failed joints
If you let a flat or house near Harpenden station, failed wall and movement joints let damp in, so they’re worth checking between tenancies.
Before you book anyone
- When the joint can take water or movement
- What preparation is included
- Who turns up on the day
- Whether you can choose the colour
How to look after the new joints
Good habits help new joints last longer. Our tips:
- Clear growth from the base of walls and joints
- Ask before painting over external sealant
- Keep movement joints as flexible joints, not mortar
- Keep high-pressure jets off the joints
Only paint over the joint if we have confirmed the sealant can take paint. Many exterior sealants aren’t designed to be painted.
Water getting behind cladding or render can go unnoticed for a long time. By the time there’s a damp patch, the damage can be well established.
Common questions in Mackerye End
Do you cover smaller places like Mackerye End?
Yes, Mackerye End is covered. 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.
Can you do external mastic in Mackerye End?
Yes, Mackerye End is within the area we cover. We work across London and the South East. Just call 0345 464 0079 or drop us an email with a few details of the job.
Will the new joint stand out?
There’s a good range of exterior colours, including greys, browns, whites and stone tones. We choose the closest to your brick or render.
What’s an expansion joint in brickwork?
Most straight vertical gaps in brickwork are movement joints. It gives the wall room to move.
What do you need from me for a quote?
A short description and the location, with photos by email if possible. If we need more, we will ask.
Are you insured?
Yes. We’re fully insured.
How long before the joint can be used?
Different products cure at different speeds, so follow the cure time we give you when we finish.
Do you take out the old sealant first?
Yes, every time. New sealant won’t bond properly to old, so any old material comes out before anything new goes in.
External mastic in Mackerye End: local notes
London and the South East are among the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast. With historic houses such as Shaw's Corner (about 2.3 miles east) nearby, there’s older building stock in the area around Mackerye End as well as newer homes. Where a home is older, older walls and rooflines need a sealant that moves with them and suits the material.
For site and facilities teams at buildings such as Sauncey Wood Primary School, its movement joints, gutters and trims need looking after like any other building’s. In the older streets around All Saints, older walls, gutters and the joints where extensions meet them need a flexible sealant.
Mackerye End is about 1 mile north-east of Harpenden, in Hertfordshire. For external mastic in and around Mackerye End, please call 0345 464 0079 or drop us an email for a quick quote. We’re based in Crawley and cover Hertfordshire, Mackerye End included. Our area takes in 381 places across Hertfordshire, from the larger towns to small villages. There’s also a page for London, roughly 25 miles from Mackerye End.
All of AL5 is covered for external mastic. Nearby, we also carry out external mastic in Lea Valley (1 mile south), Porter's End (1 mile north), The Folly (1 mile south-east), Blackmore End (1 mile north-east) and Bower Heath (1 mile north-west). Within a short drive, we also cover Watford (12 miles south), Hemel Hempstead (8 miles south-west), Stevenage (8 miles north-east), St Albans (5 miles south), Welwyn Garden City (6 miles east) and Hitchin (9 miles north).
Around Mackerye End
Around Mackerye End, our work takes us to homes and buildings near The Cherry Trees pub, Sir John Lawes School and Lydekker Park. For rail, the closest station is Harpenden station, roughly 1.7 miles south-west of the centre. Other landmarks nearby include St Albans City Hospital (4.8 miles south) and Harpenden Museum (1.9 miles south-west). Green spaces nearby include Wheathampstead Local Nature Reserve.
Nearby places to Mackerye End
What else we do in Mackerye End
What we do, step by step
Every visit runs the same way: we look at the joints together, protect the area around them, do the work and tidy away. Most jobs take a few hours to a few days, depending on the length of joint and the access. Somewhere as small as Mackerye End, access is often the only tricky part. For outside work, also let us know about exposed walls and any outbuildings involved.
- First, the joints are inspected and the access agreed.
- We cut out the old mastic and rake out anything in the joint.
- The faces are brushed clean and primed where the product requires it.
- We fit closed-cell backing rod to control the depth.
- The exterior sealant is applied, tooled and checked along its length.
Getting ready for the visit
- Tell us about access, such as stairs, a lift or high-level joints
- Mention any sign-in or site rules at work premises
- Tell us about any previous sealing or DIY attempts
Ask for a quote
Getting a quote is simple: let us know the job and the location and its rough size. Photos by email help us understand the job, and we’ll take it from there.