Hampshire · England
External Mastic in Longmoor
Sealing brickwork movement joints, render, cladding and façade joints for homeowners, landlords and businesses in Longmoor. ARBOMaster approved applicators, fully insured, with a 12-month guarantee.
- Plants rooting in failed movement joints
- Damp patches traced to an open external joint
- Rigid filler in a joint that should flex
Keeping the joints in good condition
To keep the joints looking good and working properly:
- Avoid pressure-washing directly into sealant joints
- Ask before painting over external sealant
- Look over the joints every year, ideally after winter
- Act on the first splits you see
Give the sealant the cure time we tell you before anything rubs against it. The surface skins over quickly, but full cure takes longer.
Gaps, plants or missing sealant in a joint are worth getting looked at. Early work is quicker and leaves a better finish.
About our external mastic in Longmoor
A movement joint is a deliberate break that lets a wall expand and contract. The sealant in it has to stretch and squeeze for years, so once it splits or hardens, the joint stops working and water gets in. We work on joints between brick and frames, façade panels and copings & trims, and the jobs we see most are weeds or debris growing in open joints and brick movement joints where the sealant has split.
In a village or hamlet like Longmoor, older cottages and farm buildings often stand in the open, where walls and rooflines take the weather head on. Joints on those walls need a sealant that moves with the building and stays in place.
Our work is backed for twelve months, and the guarantee is the same wherever you are.
- Place
- Longmoor (GU33)
- Wider area
- Hampshire
- Guarantee
- One year on every job
- Price
- Quoted before any work starts
- Call
- 0345 464 0079
- Updated
- 26 October 2026
For landlords and businesses
We also work for property managers and facilities teams in Longmoor and across Hampshire. Several sites can be quoted together.
Whether it’s one flat or a portfolio, the work is the same standard: old sealant fully removed, joints prepared properly and a one-year guarantee.
DIY versus a professional finish
If you do try it yourself, take your time over the preparation: remove every trace of old sealant, clean and dry the joint, and follow the product’s cure time. If it fails, we can still redo it.
Some jobs are best left to a professional: high-level joints, fire-rated gaps, external movement joints and big jobs call for the right materials, safe access and experience.
Walls and rooflines in Longmoor
Rainfall in the South East is lower than in much of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
Managing a site like Greatham Primary School? Then movement joints, cladding joints and gutters on larger buildings need the same care as a house’s. Rented homes near Liss station change hands often, and split movement joints are easy to miss on a rental until damp shows inside.
Longmoor is about 3 miles south of Bordon, in Hampshire. Longmoor gets the same service as everywhere we cover: old sealant removed completely, careful preparation and a one-year guarantee. Our Hampshire coverage runs to 683 places, and Longmoor is one of them. We also work in Portsmouth, around 20 miles away.
Jobs for external mastic in GU33 works the same way as everywhere else we cover. Local streets include Woolmer Road, Roberts Road and Methuen Road, and we cover them all. If you are just outside Longmoor, we cover Greatham (1 mile west), Woolmer (1 mile north-west), Liss Forest (2 miles south-west), The Mint (2 miles south) and Blackmoor (2 miles north-west). Within a short drive, we also cover Havant (15 miles south), Fleet (14 miles north), Horndean (13 miles south-west), Aldershot (13 miles north), Alton (7 miles north-west) and Waterlooville (15 miles south-west).
Local landmarks in Longmoor
The closest station to Longmoor is Liss station, about 2.3 miles south-west of the centre. A little further out are The Romany Museum (3.4 miles north-west) and Chase Community Hospital (2.3 miles north). Green spaces nearby include Wheeler's Down and Liss Riverside Railway Walk North.
What happens on the day
Most of a good job is in the preparation, so that’s where we spend the time. Every joint is cleaned and dried before new material goes in. All told, the work takes a few hours to a few days, depending on the length of joint and the access. Somewhere like Longmoor needs a little journey planning: 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 inspect the joints and agree which need resealing and how they’ll be reached.
- Old sealant and any debris are cut and raked out.
- The joint faces are cleaned and primed where the sealant needs it.
- Closed-cell backing rod is fitted to set the depth and stop three-sided bonding.
- We gun in a flexible exterior sealant in a colour that suits the wall and tool it neatly.
Before we arrive
- Mention any sign-in or site rules at work premises
- Plan for the work area to be out of bounds to pets and children
- Mention any parking rules near the property
How to get a quote
We quote each job on its own. Simply ring 0345 464 0079 or send us an email and describe the job and send photos if you have them.
Advice
Towns and villages near Longmoor
What else we do in Longmoor
Longmoor: your questions answered
Can you do external mastic in Longmoor?
Yes. We work across London and the South East, and Longmoor is part of that. Just call 0345 464 0079 or send us an email with a few details of the job.
I let a flat near Liss station. Can you help?
Yes, landlords and agents are among the people we work for, and several properties can go on one quote. Just call 0345 464 0079 or drop us an email with the address and what needs doing, and we’ll give you a clear quote.
Do I have to be there?
If the work is inside, we need someone to let us in. Once we have agreed the job, you do not need to watch us work.
Where do you work from?
We work from Crawley. We cover Longmoor and the rest of Hampshire, along with the rest of our area.
How long should I leave it?
Many sealants skin over quickly but take longer to cure fully. We’ll give you the cure time for the product we used before we leave.
What’s an expansion joint in brickwork?
Most straight vertical gaps in brickwork are movement joints. It gives the wall room to move and needs a flexible seal, not mortar.
What colours does the sealant come in?
We choose a sealant colour to suit the brick, stone or render. Exterior sealants come in a good range of colours.
Do the sealants smell?
Some sealants have a smell while they cure, but it fades. Ventilation helps.
What happens if it’s left?
Sealing over the top of old mastic does not hold for long. The new layer can’t bond properly to old, weathered material, so we always take the old sealant out. Where a wall is exposed, as many are in small places like Longmoor, wind-driven rain gets into any failed joint, and older walls, once damp, take a long time to dry.
The cost reflects the work involved, not a rough estimate. That’s why we ask a few questions first.
Why Longmoor customers choose us
- Fully insured
- Tidy, careful work
- White, clear, grey or another colour, product permitting
- Anti-fungal sanitary silicone in wet areas
Take a look at our cost guide or what customers say.
What the job involves on each surface
Concrete and blockwork
Big joints in concrete need careful depth control. We size the backing rod to the gap so the sealant isn’t too deep.
Brickwork movement joints
Clay brickwork grows slightly over its life and moves with the weather. That movement goes into the joint, so its sealant has to stay flexible.
How we quote for external mastic
Some jobs are bigger than they look, and some smaller. The main factors:
- Mould in or behind the old joints
- The old material and how stubborn it is
- The number and length of the joints
- The type of sealant required
Rather than a set price list, we look at what your job involves: how many joints, what’s in them now and how we reach them. You will know the price before we begin.
What we need to know
The more you tell us, the more accurate the quote. When you ask for a quote, tell us:
- Photos by email, if that is easy
- The address or postcode of the job
- Any access issues, like height or stairs
- The rough size of the job
A good description makes for an accurate quote. Let us know the location, the problem and roughly how many joints, and email photos if that is easy.