Southampton · England
External & façade joints in St Mary's, Southampton
Professional external mastic in and around St Mary's, with old sealant always removed completely and a 12-month guarantee.
- Leaking joints around cladding and façade panels
- Plants rooting in failed movement joints
- Rain getting behind render or cladding at a joint
How we handle external mastic in St Mary's
Short cuts in external joints show up within a season or two. Overfilled joints, missing backing rod and sealant laid over old sealant all tend to fail early. We strip the joint back and start again. If you’re dealing with plants rooting in failed movement joints and damp patches traced to an open external joint, we can help.
Houses in smaller places like St Mary's can stand more in the open than those in a built-up town, so exposed walls and rooflines take more wind-driven rain. Joints on those sides are normally the first to go.
We stand behind the work with a 12-month guarantee, so you are covered after we’ve gone.
- Where
- St Mary's (SO14, SO15, SO18)
- Region
- Southampton
- Cover
- One year on every job
- Quote
- A clear quote up front
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
Different surfaces, different methods
Concrete and blockwork
Big joints in concrete need careful depth control. Backing rod sized to the joint sets it so the sealant isn’t too deep.
Render joints
Cracks along render joints let water in behind the coat. A sound joint keeps the render dry behind and helps it last.
Common questions in St Mary's
Can you help a landlord with a rental near Southampton Central station?
Yes. We work for letting agents and landlords as well as homeowners, and several properties can go on one quote. Just call 0345 464 0079 or email us with the address and what needs doing, and we’ll give you a clear price.
Is St Mary's within the area you cover?
Yes. St Mary's is within the area we cover, which takes in towns, villages and rural addresses. We work across London and the South East. Just mention lanes, gates or anything else about the route when you book.
Do you remove the old sealant?
Yes, every time. New silicone does not stick to old silicone, so the joint is cleaned back first.
Where is Mr Mastic based?
We work from Crawley. Our applicators cover St Mary's.
Do you guarantee your work?
Yes. There’s a 12-month guarantee on every job, large or small.
Which products do you use?
It depends on the joint: sanitary silicone where it gets wet, and sealants suited to movement or weather elsewhere. We use products from Arbo and Everbuild.
Can you match the colour of my brickwork?
There’s a good range of exterior colours, including greys, browns, whites and stone tones. We pick the one that suits your wall best so it does not stand out.
How much does external mastic cost in St Mary's?
Every job is different, so each one gets its own quote. To get one, phone 0345 464 0079 or drop us an email and tell us what needs doing and where.
Landlord and commercial work in St Mary's
A neglected joint can let water reach the structure, which matters even more when someone else lives there. Resealing at the right time is simple maintenance that we can handle for you.
Letting agents often deal with us directly. Send the address, what’s needed and the access arrangements and we’ll quote.
Can I do it myself?
The biggest DIY mistake is sealing over old sealant. Silicone does not stick to old silicone, so it lifts and traps water and mould underneath. Everything old must be removed first.
Overfilling a joint is a classic DIY mistake. A thick, smeared bead looks untidy and does not move well, and getting the depth right matters as much as the look.
When to call us in St Mary's
Many joints fail because they were sealed too deep or with nothing behind them. Sealant bonded to three sides has nowhere to go and rips as the joint opens.
People generally contact us after spotting something like this:
- Panel joints letting water in
- Water getting into walls through failed joints
- Joints pointed up with cement by mistake
- Hard, crazed mastic that has stopped moving
Homes close to St Mary's Church include some older properties, and older walls, gutters and the joints where extensions meet them need a flexible sealant.
Comparing quotes
- What preparation is included
- What the quote includes, VAT included or not
- What product goes in the joint
- Who does the work, and how experienced they are
Towns and villages near St Mary's
More services for St Mary's
When it isn’t the sealant
Before booking, it’s worth knowing the limits:
- Failed render or damaged cladding panels
- Walls that need new movement joints cut into them
- Rising or penetrating damp from elsewhere in the wall
If you are not sure, just call 0345 464 0079 or drop us an email and we will give you a straight answer before booking.
Where we work in St Mary's
- Concrete & block
- Render & cladding joints
- Joints between brick and frames
- Façade panels
- Brickwork movement joints
- Copings & trims
External mastic in St Mary's: local notes
St Mary's is close to the coast, where wind-driven rain is a fact of life and, nearer the shore, so is salt air. That’s hard on movement joints and outside wall joints, especially on the side facing the sea. The South East is one of the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
Schools such as Hope Community School Southampton are buildings too, and larger buildings have long runs of movement joint that eventually need resealing. Letting a property close to Southampton Central station? Then outside joints that have cracked can let damp into a rental, so check them between lets.
St Mary's is about 1 mile south of Southampton, in Southampton. Wherever you are in the SO14 postcode area, we cover external mastic for homes and businesses. St Mary's is one of 40 towns and villages in Southampton we cover for external mastic.
Jobs for external mastic in SO14, SO15 and SO18 works the same way as everywhere else we cover. You will find streets such as New Road, Ogle Road and Marsh Lane, and we cover them all. We also cover Northam (1 mile north-east), Inner Avenue (1 mile north), Peartree Green (1 mile east), Southampton (1 mile north) and Bitterne Manor (1 mile north-east). Larger places within reach include Chartwell Green (3 miles north-east), Harefield (3 miles east), Maybush (3 miles north-west), Coxford (3 miles north-west), Lordswood (3 miles north-west) and Eling (4 miles west).
Around St Mary's
Around St Mary's, our work takes us to homes and buildings near The Joiners pub, Woolston School and Houndwell Park and the streets around them. The nearest railway station is Southampton Central station, roughly 0.8 miles west of the centre. Well-known places in the area include Netley Castle (2.5 miles south-east) and Bargate Guildhall Museum (under half a mile south-west). Green spaces nearby include Netley Common.
Leave it or put it right?
The longer a joint stays open, the more water the wall takes in. Wet masonry is more easily damaged by frost, so the damage spreads beyond the joint. In an older home around St Mary's, damp from a failed joint can get into timber and plaster, which is far harder to put right than the sealant itself.
Instead of a standard rate, we look at what your job involves: the amount of work, the old material and the access. The price is agreed before we begin.
Why choose Mr Mastic in St Mary's
- A sealant colour to suit the surroundings
- Any old sealant cut out fully, not covered over
- Fully insured
- Quality sealants from Arbo and Everbuild
Read how sealant jobs are priced and customer reviews.
The process
The work is kept neat and contained to the area we’re working on, 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. In a smaller place like St Mary's, parking is seldom the issue; lanes, gates and long drives are worth mentioning. For outside work, side access and the height of the joints help us plan.
- We start by walking round the building and agreeing the joints and the access.
- Every bit of old sealant and any mortar or debris is cut out.
- 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.
How to prepare
- Let us know about parking restrictions
- Move anything stored near the joints
- For business premises, tell us about site rules or sign-in
How to get a quote
Want a quote for external mastic? Please phone 0345 464 0079 or email us with a few details. You’ll know what we plan to do, and what it will cost, before any work begins.