Buckinghamshire · England
External Mastic in New Zealand
Our applicators work in New Zealand on sealing brickwork movement joints, render, cladding and façade joints. Old material cut out, joints cleaned and sealed neatly.
- Weeds or debris growing in open joints
- Rain getting behind render or cladding at a joint
- Failed seals between different materials
External mastic in New Zealand
For buildings in New Zealand, we reseal external joints of all kinds, from brick movement joints to cladding panels. Every joint gets the same careful preparation: clean joint faces and the right depth. If you’re dealing with cracked joints where brick meets render or frames and sealant pulling away from one side of the joint, we can put it right, whatever the surface.
Outside joints can only be sealed when they’re dry, so work in New Zealand is booked around the forecast. Tell us about access to all sides of the building, including outbuildings and garages.
Whatever the size of the job, it’s backed by our one-year guarantee in New Zealand and across Buckinghamshire.
- Where
- New Zealand (HP19, HP20)
- Wider area
- Buckinghamshire
- Cover
- A year, on every job
- Quote
- A clear price before we start
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
Keeping the joints in good condition
No joint lasts for ever, but care makes a real difference. A few tips:
- Show decorators and builders where the movement joints are
- Check external joints each spring
- Keep soil, plants and ivy away from the joints
- Leave the joints unpainted unless we have said otherwise
Look over the joints once a year, ideally after winter. Splits, gaps at the edges or plants in the joint are early warning signs.
Small splits are the time to act. At that stage it’s a simple cut out and reseal with no damage behind it to deal with.
Walls and rooflines in New Zealand
The South East is one of the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
Managing a site like Elmhurst School? Then larger buildings have long runs of movement joint that eventually need resealing. Rented homes near Aylesbury station change hands often, and failed wall and movement joints let damp in, so they’re worth checking between tenancies.
New Zealand is about 1 mile west of Elmhurst, in Buckinghamshire. Homes, rented property, offices and hotels in New Zealand can book us for external mastic, old or new, large or small. The work is guaranteed for a year. Our Buckinghamshire coverage runs to 263 places, and New Zealand is one of them. You can also see our page for Oxford, about 19 miles away.
We work across the HP19 and HP20 postcode area for external mastic. Streets in the area include Dunsham Lane, Drayton Road and Cannock Road, and we cover them all. If you are just outside New Zealand, we cover Elmhurst (1 mile east), Aylesbury (1 mile south), Watermead (1 mile north-east), Quarrendon Estate (1 mile west) and California (1 mile south). Larger places within reach include High Wycombe (14 miles south), Chesham (12 miles south-east), Buckingham (14 miles north-west), Amersham (14 miles south-east), Princes Risborough (7 miles south) and Haddenham (6 miles south-west).
Landmarks near New Zealand
Typical jobs here are in homes near The New Zealand pub, Buckinghamshire UTC and The PACE Centre and the streets around them. For rail, the closest station is Aylesbury station, about 0.8 miles south. Well-known places in the area include Royal Buckinghamshire Hospital (under half a mile south) and Dinton Castle (3.8 miles south-west).
Common questions in New Zealand
Do you cover New Zealand for external mastic?
Yes. Our work covers London and the South East, and New Zealand is part of that. Just phone 0345 464 0079 or email us with a few details of the job.
Do you work for landlords with property near Aylesbury station?
Yes, landlords and agents are among the people we work for, and several properties can be quoted together. Just call 0345 464 0079 or send us an email with the address and what needs doing, and we will send you a clear quote.
Do you seal joints where cladding meets other materials?
Yes. Materials like render, brick, metal and uPVC all move differently, so a flexible sealant is needed where they meet. We choose one that suits both surfaces.
Can a movement joint be filled with mortar?
No. Mortar locks the joint solid, so the movement cracks the wall elsewhere. Use a flexible sealant with backing rod.
What is backing rod for?
That’s backing rod, a closed-cell foam. It keeps the sealant at the right depth and bonded to the sides only so it can flex with the joint.
Do I have to be there?
That depends on where the joints are. Inside work needs someone to give us access.
Are you insured?
Yes. We are fully insured for every job we do.
What information do you need?
Just the basics: where it is, what you’ve noticed and how we reach it. Then call 0345 464 0079 or email us.
What we do, step by step
The work is kept neat and contained to the joints we are treating, so you can get on with your day. Expect the work to take anything from a few hours to several days, depending on the building, and we explain the cure time before we leave. For a village or hamlet like New Zealand, the journey is planned in advance: let us know about lanes, gates and parking. We bring what the job needs, so it can be finished in one trip where possible.
- We look at every joint and agree a colour to suit the wall.
- We take out the old sealant until the faces are sound.
- Closed-cell backing rod is pushed in so the sealant bonds to two sides only.
- Primer is applied wherever the sealant needs it.
- We gun in low-modulus sealant and tool it neatly.
Preparing for the visit
- Let us know if you’ve seen damp or leaks
- Let us know about parking restrictions
- For indoor joints, keep the area dry beforehand if you can
Get a quote
A good description makes for an accurate quote. Tell us where the job is, what’s wrong and how much there is, and email photos if that’s easy.
Read more
What happens if it’s left?
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 doesn’t last so it’s worth doing right. Around New Zealand, older homes often have timber in their floors and frames, and water through a failed joint can rot timber if it’s left.
What it costs depends on the size of the job, how hard the old material is to remove and access to the work. We give a clear quote before any work starts.
Why choose Mr Mastic in New Zealand
- Colour agreed with you before work begins
- Homes, businesses and hotels
- Rated 4.9 stars on Google
- We leave the area clean and tidy
Take a look at how sealant jobs are priced and our reviews.
How we quote for external mastic
We don’t publish a price list, because no two jobs are the same. The quote depends on:
- How many rooms, windows or areas are involved
- The number and length of the joints
- The type of sealant required
- Whether the work is at height
Commercial jobs are quoted on the same basis as homes: 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.
What we need to know
You don’t need to know the technical terms. It helps if you can tell us:
- How we’d reach the joints
- Whether it has been sealed before
- The problem you’ve noticed
- The address or postcode of the job
Call for a quick quote, or email us if that is easier. Describe what needs sealing and we’ll talk you through the work before giving you a price.
Surface by surface
Concrete and blockwork
The face of concrete or block is often dusty, so preparation is key. A primer goes on where the product requires one before sealing.
Joints between dissimilar materials
Where a frame or panel meets masonry, water often finds a way in. We cut out the old sealant and reseal with a product suited to both surfaces.
What we’re called out for in New Zealand
Buildings move more than people expect. Clay bricks expand slightly over their life, concrete and block shrink, and everything moves with temperature and wet. All of that ends up in the joint sealant.
Look out for these signs:
- Joints pointed up with cement by mistake
- Sealant pulling away from one side of the joint
- Water getting into walls through failed joints
- Plants rooting in failed movement joints
For an older house near a landmark such as St Peter's, older walls, gutters and the joints where extensions meet them need a flexible sealant.
What to look for in a quote
- The length of the guarantee
- What happens if the job turns out different
- How the surfaces are prepared before sealing
- Which sealant they’ll use, and why
Should I try it myself first?
If you’re 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 fails, we can still redo it.
The biggest DIY mistake is sealing over old sealant. New silicone won’t bond to old, so it lifts and traps water and mould underneath. Everything old must be removed first.