Hertfordshire · England
External & façade joints in Stevenage, Hertfordshire
External mastic for Stevenage and the surrounding area: the right sealant, proper preparation and a neat finish. Call for a quick quote.
- Joints pointed up with cement by mistake
- Rain getting behind render or cladding at a joint
- Plants rooting in failed movement joints
Looking after it afterwards
A little care helps the new joints last. We recommend:
- Never let anyone fill a movement joint with mortar
- Check the sealant is paintable before painting near it
- Show decorators and builders where the movement joints are
- Get split or bare joints resealed while the damage is small
Give the sealant the cure time we tell you before anything rubs against it. The surface skins over quickly, but full cure takes longer.
Once a joint cannot move, the wall finds another way, often as cracks near the joint. Resealing it early helps prevent that.
External mastic in Stevenage
On houses, flats and commercial buildings across Stevenage, we reseal joints in brickwork, render, cladding and façade panels. The preparation is the same whatever the wall: clean, sound faces and a controlled depth. If you’re dealing with failed seals between different materials and joints pointed up with cement by mistake, we can put it right, whatever the surface.
Larger buildings in Stevenage have plenty of movement joints, cladding joints and roofline trims. A failed joint lets water behind the brick or render, where it often goes unnoticed for a while.
You are covered for a year from the day we finish. If anything is not right with it, call 0345 464 0079 or email us.
- Location
- Stevenage (SG1, SG2, SG3)
- Wider area
- Hertfordshire
- Guarantee
- One year on every job
- Price
- A clear price before any work starts
- Call
- 0345 464 0079
- Updated
- 26 October 2026
FAQs for Stevenage
Do you cover Stevenage for external mastic?
Yes, Stevenage is within the area we cover. We work across London and the South East. Just phone 0345 464 0079 or drop us an email with a few details of the job.
Is it worth replacing old sealant in an older home in Stevenage?
In most cases, yes, if it hasn’t been done for a while. Sealant is a maintenance item: how long it lasts depends on use, cleaning and exposure, and many homes in Stevenage may already be on their second or third set.
Can a movement joint be filled with mortar?
No. A mortar-filled joint can’t move, so the wall cracks somewhere else instead. Use a flexible sealant with backing rod.
Is there any odour?
That depends on the sealant. Some smell for a while, some hardly at all.
Can you reach joints on upper floors?
It depends on the building. Where joints can be reached safely, we will do them. Give us some details and we’ll confirm the access.
Are you an approved applicator?
Yes. Mr Mastic is an ARBOMaster approved applicator, and we’re fully insured.
Can landlords and businesses book you?
Yes. As well as homeowners, we work for landlords, agents, businesses and hotels across Hertfordshire.
What do you need from me for a quote?
A short description and the location, plus pictures if you have them. If we need more, we’ll ask.
Stevenage buildings and the weather
Stevenage was built as one of England’s post-war new towns. Homes here were built in phases, many of them in the post-war decades, so neighbouring houses often have rooflines and wall joints of the same age, wearing out at the same time. The South East is one of the drier parts of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
If you let a flat or house near Stevenage station, failed wall and movement joints let damp in, so they’re worth checking between tenancies. Managing a site like Saint Vincent de Paul Catholic Primary School? Then its movement joints, gutters and trims need looking after like any other building’s.
Stevenage is about 26 miles east of Milton Keynes, in Hertfordshire. If you need external mastic in Stevenage, it’s easy to get a quote: please phone 0345 464 0079 or email us. We cover Hertfordshire from our Crawley base. Stevenage is one of 381 towns and villages in Hertfordshire we cover. You can also see our page for London, roughly 29 miles from Stevenage.
Every address in SG1, SG2 and SG3 is within our area for external mastic. You will find streets such as King Pin Square, Market Square and Market Place. Being close to the A602 and B197, Stevenage is simple for us to get to for external mastic. Nearby, we also carry out external mastic in Bedwell (1 mile south-west), Pin Green (1 mile north-west), Chells (1 mile east), St Nicholas (1 mile north) and Rooks Nest (1 mile north). We also work in nearby towns such as St Albans (13 miles south-west), Bishop's Stortford (15 miles east), Welwyn Garden City (8 miles south), Harpenden (10 miles south-west), Hitchin (5 miles north-west) and Hoddesdon (13 miles south-east). Stevenage is among the bigger towns we cover in Hertfordshire.
What’s near Stevenage
We work in homes and buildings around The Heathcote School, Church of Saint Nicholas and Marriotts School and the streets around them. For rail, the closest station is Stevenage station, about 1.2 miles south-west of the centre. A little further out are Benington Castle (2.9 miles east) and Stevenage Museum (0.8 miles south-west). Not far away are Pryor's Wood.
Landlords, agents and businesses in Stevenage
We also work for businesses, from offices to washrooms and kitchens. On commercial sites, working times can be discussed when we quote.
We also work for property managers and facilities teams. We can quote a run of properties together, and we are fully insured for the work.
When to call us in Stevenage
If plants are growing out of a joint, the sealant has usually failed or was never there. Roots and dirt hold water against the wall and make things worse.
Any of these means the joints need attention:
- Moss and dirt in joints with no sealant left
- Rain getting behind render or cladding at a joint
- Old sealant gone brittle and cracked
- Cracked joints where brick meets render or frames
If you live in an older home near St Hugh & St John, old and new materials meet at the roofline and walls, which is where sealant earns its keep.
Comparing quotes
- Who turns up on the day
- What insurance they hold
- How long to leave it before use
- Whether they seal over old material or remove it
How the visit works
We work through the job in order: protection first, then preparation, sealing and a tidy-up. Typically it takes a few hours for a handful of joints, longer for a whole elevation, and the area is left clean. In central Stevenage, parking can be tight, so tell us about driveways, permits or nearby car parks. For flats, mention stairs, lifts and shared entrances as well.
- 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.
- We clean both faces of the joint and prime them where the product calls for it.
- Backing rod goes in next, setting the depth and keeping the sealant off the back of the joint.
- We gun in a flexible exterior sealant in a colour that suits the wall and tool it neatly.
Preparing for the visit
- Tell us about any water getting in
- Mention if the joints have been sealed before
- Where the joints are inside, avoid wetting them before we arrive
Getting a quote
We quote each job on its own. Just call 0345 464 0079 or send us an email with the details, and photos are welcome.
Related advice
DIY sealant or a professional job?
Some jobs are best left to a professional: work at height, external movement joints, fire-rated sealant and large areas need the right product, the right access and the right method.
The difference is mostly in the preparation and the product. We take joints back to clean, dry surfaces, and the sealant is chosen for how the joint moves and where it is.
Why deal with it now?
Sealing over the top of old mastic does not hold for long. New sealant does not bond well to old, weathered sealant, so we always take the old sealant out. In flats, shops and offices in Stevenage, a failed joint can let water into the unit below or behind a wall, where it can go unnoticed until the damage is done.
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.
Why choose Mr Mastic in Stevenage
- White, clear, grey or coloured to suit, where the product allows
- Tidy, careful work
- Colour agreed with you before work begins
- ARBOMaster approved applicator
Nearby places to Stevenage
What else we do in Stevenage
Quotes for external mastic in Stevenage
Every job gets its own quote. This is what makes a difference:
- Mould in or behind the old joints
- The number and length of the joints
- Which sealant suits the joint
- The old material and how stubborn it is
No two jobs are quite the same, so each one gets its own quote. The number of joints, how easy they are to reach and the sealant needed all make a difference.
Asking for a quote
You don’t need to know the technical terms. Just tell us:
- Roughly how big the job is
- The type of property
- Pictures of the joints, sent by email
- If someone has resealed it before
Asking for a quote is easy: let us know the job and the location and its rough size. A few photos by email make the job easier to understand, and we will take it from there.