Hampshire · England
External Mastic in St Cross
External mastic in St Cross from a team with over 20 years’ experience. Rated 4.9 on Google from 180+ five-star reviews.
- Sealant that has lost its bond to the brick or render
- Rain getting behind render or cladding at a joint
- Movement joints filled with mortar instead of sealant
External mastic for homes and businesses in St Cross
Getting the depth right is half the job. Closed-cell backing rod sets the depth and stops the sealant sticking to the back, so it bonds to the two sides only and can stretch. Common call-outs are for gaps where render, brick and frames meet and brick movement joints where the sealant has split, across joints between brick and frames, copings & trims and concrete & block.
Outbuildings, garages and conservatories around homes in places like St Cross add more joints to look after. Leaks generally start at a gutter end, a garage door frame or where an extension meets the house.
Your job is guaranteed for a year, as with all our work.
- Location
- St Cross (SO22, SO23)
- Region
- Hampshire
- Cover
- 12 months on all our work
- Price
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
What we do, step by step
The work is kept neat and contained to the joints we’re 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 tell you how long to leave it before we go. Parking around St Cross is generally easier than in a town centre, but mention any lanes, gates or long drives. If the job is outside, tell us about side access and how high the joints are.
- First, the joints are inspected and the access agreed.
- Every bit of old sealant and any mortar or debris is cut out.
- Joint faces are cleaned back and primed if the sealant needs it.
- We fit closed-cell backing rod to control the depth.
- We apply the sealant, tool it and check the whole run.
Before we arrive
- Let us know about earlier repairs to the joints
- Keep children and pets away from the work area
- Mention any tricky access
Ask for a quote
We don’t publish a price list, as no two jobs are quite the same. Instead, your job gets its own clear quote. To get started, ring 0345 464 0079 or drop us an email.
Related advice
Questions from St Cross
Do you cover smaller places like St Cross?
Yes. St Cross is within the area we cover, which takes in towns, villages and rural addresses. Our work covers London and the South East. Just mention lanes, gates or anything else about the route when you book.
Do you work for landlords with property near Winchester station?
Yes, landlords and agents are among the people we work for. Just call 0345 464 0079 or drop us an email with the address and what needs doing, and we’ll give you a clear price.
When will the joints need doing again?
That depends on the wall, the weather and the movement. Look for splits, hardening or edges coming away, and reseal at that point.
Can you quote for more than one area?
Of course. Doing several areas at once is generally more efficient.
Do the sealants smell?
That depends on the sealant. Some smell for a while, some hardly at all, and any smell fades as they cure.
Do you work at height?
Each building is different. Send us photos and a rough idea of the height, and we’ll confirm what access is needed.
Will the old sealant be removed?
Always. Sealing over old sealant is the main reason resealing fails early, so we never do it.
Are you an approved applicator?
Yes. We hold ARBOMaster approved applicator status, and we’re fully insured.
What sealant work can’t fix
Before booking, it’s worth knowing the limits too:
- Adding movement joints to masonry that has none
- Render that’s blown, hollow or coming away
- Cracked brickwork or render that needs a builder or plasterer
If in doubt, call 0345 464 0079 or send us an email and we will say what we think before booking.
What we seal
- Brickwork movement joints
- Copings & trims
- Joints between brick and frames
- Concrete & block
- Render & cladding joints
- Façade panels
Keeping the joints in good condition
Looking after new joints is easy, and it makes a real difference:
- Make sure movement joints aren’t pointed over
- Fix overflowing gutters above sealed joints
- Tell anyone working on the walls about the movement joints
- Walk round the building once a year and look at the joints
Avoid pressure-washing straight into the joints. High-pressure water can lift the edges.
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 so early resealing is worth it.
Also near St Cross
Also in St Cross
What the job involves on each surface
Render joints
Water behind render can lead to blown patches. A sound joint keeps the render dry behind and helps it last.
Joints between dissimilar materials
Each side of the joint may need its own preparation. Both surfaces are cleaned and primed as the product requires.
When to call us in St Cross
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.
Look out for these signs:
- Panel joints letting water in
- Movement joints filled with mortar instead of sealant
- Old sealant gone brittle and cracked
- Moss and dirt in joints with no sealant left
Rented homes near Winchester station change hands often, and split movement joints are easy to miss on a rental until damp shows inside.
What to look for in a quote
- Who turns up on the day
- Whether they seal over old material or remove it
- How hidden problems are handled
- What the quote includes, VAT included or not
DIY versus a professional finish
If you’re set on DIY, put the effort into 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.
Not every job suits DIY: high-level joints, fire-rated gaps, external movement joints and big jobs call for the right materials, safe access and experience.
What external mastic looks like in St Cross
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.
If you live in an older home near St. Cross Church, the joints between older walls, newer extensions and the roofline need a sealant that can move. Managing a site like St Faith's Church of England Primary School? Then movement joints, cladding joints and gutters on larger buildings need the same care as a house’s.
St Cross is about 1 mile south of Winchester, in Hampshire. Our applicators cover external mastic for homes and businesses in St Cross and nearby. Across Hampshire, we cover 683 places, and St Cross is one of them. Southampton is on our list too, around 10 miles away.
Work in SO22 and SO23 works the same way as everywhere else we cover. That includes homes and businesses on Edgar Road, Hubert Road and Grange Road and the roads around them. Nearby, we also carry out external mastic in Badger Farm (1 mile west), Stanmore (1 mile north-west), Winchester (1 mile north), Bar End (1 mile east) and Highcliffe (1 mile north-east). Within a short drive, we also cover Eastleigh (6 miles south), Fareham (15 miles south), Andover (13 miles north-west), Totton (12 miles south-west), Chandler's Ford (5 miles south-west) and Hedge End (9 miles south).
Near you in St Cross
Typical jobs here are in homes near St. Cross Park, The Bell Inn Public House and Kings' School and the streets around them. The closest station to St Cross is Winchester station, about 1.3 miles north. A little further out are The Gurkha Museum (0.6 miles north-east) and Royal Hampshire County Hospital (0.9 miles north). Open spaces near St Cross include Hockley Meadows and Twyford Down.
Why it’s worth doing now in St Cross
Mortar or ordinary filler might look like a quick way to close an open joint, but it locks the joint solid. The movement then cracks the brickwork or render nearby. The correct repair is a flexible sealant with the right backing. In an older home around St Cross, damp from a failed joint can get into timber and plaster, which is far harder to put right than the sealant itself.
Doing several joints on one visit is usually more efficient than separate visits, so it’s worth mentioning everything you’d like done. You’ll get one clear quote for the whole job.
Why us?
- Rated 4.9 stars on Google
- Every job guaranteed for a year
- Anti-fungal sanitary silicone in wet areas
- Old sealant always removed completely
See our cost guide and what customers say.