Portsmouth · England
External & façade joints in Hilsea, Portsmouth
External mastic for Hilsea, by sealant specialists with 20+ years’ experience. Rated 4.9 on Google from 180+ five-star reviews.
- Damp patches traced to an open external joint
- Plants rooting in failed movement joints
- Sealant that has lost its bond to the brick or render
How we handle external mastic in Hilsea
Getting the depth right is half the job. Backing rod controls how deep the sealant goes and keeps it off the back of the joint, leaving it bonded to two faces so it can move with the wall. Common call-outs are for weeds or debris growing in open joints and weathered mastic that no longer stretches, across render & cladding joints, brickwork movement joints and concrete & block.
Homes around Hilsea range from older cottages to newer houses, with walls and rooflines of every type. Older homes need their gutter and trim joints kept tight, newer ones their movement joints.
Big or small, you get the same 12-month guarantee.
- Location
- Hilsea (PO2, PO3, PO6)
- Region
- Portsmouth
- Guarantee
- A year, on every job
- Quotes
- Quoted before any work starts
- Call
- 0345 464 0079
- Updated
- 26 October 2026
Walls and rooflines in Hilsea
Hilsea 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. 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.
For site and facilities teams at buildings such as Gatcombe Park Primary School, its movement joints, gutters and trims need looking after like any other building’s. In the older streets around St Francis' Church, an extension built onto an older house moves differently, and the joint between them takes the strain. For landlords with property near Hilsea station, outside joints that have cracked can let damp into a rental, so check them between lets.
Hilsea is about 2 miles north of Portsmouth, in Portsmouth. Homes, rented property, offices and hotels in Hilsea is covered for external mastic, old or new, large or small. Every job comes with our 12-month guarantee. Hilsea is one of 19 towns and villages in Portsmouth we cover for external mastic.
Postcode districts we cover here for external mastic: PO2, PO3 and PO6. We cover properties on Vita Road, Conan Road and Arras Road and the roads around them. Close by, we work in Cosham (1 mile north), North End (1 mile south-west), Tipner (1 mile south-west), Wymering (1 mile north) and Rudmore (1 mile south-west). Larger places within reach include Southsea (3 miles south), Portsea (3 miles south-west) and Portsmouth Point (3 miles south-west).
Local landmarks in Hilsea
We work in homes and buildings around Alexandra Park, Trafalgar School and Coach and Horses pub. Hilsea’s nearest station is Hilsea station, roughly 0.5 miles east of the centre. Nearby you will also find World War I Remembrance Centre (0.8 miles east) and Tricorn Centre (2.1 miles south-west). For a walk, there’s Milton Locks and Portsdown Hill.
What else we do in Hilsea
What affects the cost of external mastic
The quote reflects the job in front of us. We take into account:
- How many rooms, windows or areas are involved
- Any working-time requirements on site
- Which sealant suits the joint
- The number and length of the joints
Doing several joints on one visit is usually more efficient than separate visits, so it’s worth mentioning everything you’d like done. We will send you a clear quote for the lot.
What we need to know
You do not need to know the technical terms. Just tell us:
- The type of property
- The problem you’ve noticed
- The rough size of the job
- If someone has resealed it before
We do not publish a price list, because every job is different. Instead, we give you a clear quote for your job. To get started, ring 0345 464 0079 or drop us an email.
Surface by surface
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.
Cladding and façade panels
Metal and composite panels move a lot with temperature, so the joints work hard every day. The sealant is chosen with that in mind.
The process
We bring everything the job needs with us, so there’s nothing for you to buy. After a quick look at the joints together, we protect the area and start. Most jobs take anything from a few hours to several days, depending on the building. Parking around Hilsea is generally easier than in a town centre, but mention any lanes, gates or long drives. 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’ll reach them.
- We cut out the failed sealant and rake out any dirt or growth.
- The joint faces are cleaned and primed where the sealant needs 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.
How to prepare
- Mention any leaks or damp you’ve noticed
- Keep pets and children clear of the area while we work
- Mention any sign-in or site rules at work premises
Get a quote
Getting a quote is simple: let us know what needs doing and where, and roughly how big it is. A few photos by email make the job easier to understand.
Related advice
Can I do it myself?
Overfilling a joint is a classic DIY mistake. A thick, smeared bead looks untidy and doesn’t move well, and getting the depth right matters as much as the look.
The biggest DIY mistake is sealing over old sealant. New silicone will not bond to old, so it lifts and traps water and mould underneath. All the old material has to come out first.
Looking after it afterwards
Aftercare is simple:
- Get split or bare joints resealed while the damage is small
- Check external joints each spring
- Keep movement joints as flexible joints, not mortar
- Deal with leaking gutters that soak the joints below
Keep pressure washers away from the sealant. High-pressure water can lift the edges and let water in behind.
If you can see gaps, plants or bare sections in a joint, have it checked. Earlier resealing means a smaller job and a better result.
Questions from Hilsea
Do you work for landlords with property near Hilsea station?
Yes. We work for letting agents and landlords as well as householders, and several properties can be quoted together. Just ring 0345 464 0079 or drop us an email with the address and what needs doing, and we will give you a clear quote.
Does the coastal weather in Hilsea affect outside sealant?
Near the sea, outside joints face more wind, rain and salt than they would inland, so preparation and the right sealant matter all the more. Walls facing the sea are usually the first to need attention.
Will there be a smell?
Sometimes, a little. Any smell clears as the sealant cures.
Do you have insurance?
Yes. Mr Mastic is fully insured, with over 20 years’ experience in sealant work.
What sealant do you use?
Products from Arbo and Everbuild, among others, chosen to suit the joint. We explain the product when we quote.
Will the old sealant be removed?
Yes. All of the old material is cut out and the joint cleaned.
Do you guarantee your work?
Yes, for a year. If there’s a problem with our work in that time, tell us and we’ll put it right.
Can you seal joints between render and window frames?
Yes. Where different materials meet is one of the most common joints we seal. The sealant is chosen to bond to both sides, primed where needed.
When it isn’t the sealant
It helps to know what we can’t do:
- Render that’s blown, hollow or coming away
- Structural movement, which needs a surveyor or engineer
- Cracking across the wall rather than at a joint
If in doubt, phone 0345 464 0079 or drop us an email and we’ll say what we think before you book.
Surfaces we seal
- Concrete & block
- Brickwork movement joints
- Copings & trims
- Render & cladding joints
- Joints between brick and frames
- Façade panels
For landlords and businesses
In hotels, rooms out of use cost money, so the work can be planned room by room around your bookings where we can. We’ve worked in hotels as well as homes and businesses.
We also work for property managers and facilities teams in Hilsea and across Portsmouth. Several sites can be quoted together, and we’re fully insured for the work.