Hertfordshire · England
External & façade joints in High Cross, Hertfordshire
Movement joints in High Cross need attention? We cut out the old, prepare the joints and apply the right sealant, and the work is guaranteed for a year.
- Hard, crazed mastic that has stopped moving
- Sealant that has lost its bond to the brick or render
- Rigid filler in a joint that should flex
External mastic for homes and businesses in High 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 sealant pulling away from one side of the joint and damp patches traced to an open external joint, across brickwork movement joints, concrete & block and façade panels.
External sealant needs dry, clean surfaces, so work around High Cross is planned for dry weather. Tell us about access to all sides of the building, including outbuildings and garages.
A 12-month guarantee comes as standard.
- Location
- High Cross (SG11)
- Region
- Hertfordshire
- Cover
- One year on every job
- Price
- A clear quote up front
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
How to look after the new joints
A little care helps the new joints last. Our advice:
- Check external joints each spring
- Deal with leaking gutters that soak the joints below
- Keep movement joints as flexible joints, not mortar
- Wash walls gently around the sealant
Avoid pressure-washing straight into the joints. A strong jet can damage the edges of the bead over time.
A joint that has stopped moving pushes the movement elsewhere, often as cracks near the joint. Resealing it early helps prevent that.
What the job involves on each surface
Joints between dissimilar materials
Where a frame or panel meets masonry, water often finds a way in. We cut out the old sealant and reseal with a product suited to both surfaces.
Concrete and blockwork
Concrete faces can be dusty and porous, so preparation is key. A primer goes on where the product requires one.
Quotes for external mastic in High Cross
Jobs vary more than people expect. What affects the quote:
- Access and height
- Whether old sealant or filler has to be cut out
- Mould in or behind the old joints
- The product the joint needs
Doing several joints on one visit normally makes better use of the time than several visits, so tell us about everything that needs sealing. You’ll get one clear quote for the whole job.
Helping us quote
Photos help, but a description is a good start. Please mention:
- If someone has resealed it before
- Any access issues, like height or stairs
- Whether it’s a home or a business
- A few photos by email, if you can
A good description makes for an accurate quote. Tell us where the job is, what’s wrong and how much there is, and email photos if that is easy.
Leave it or put it right?
A low-modulus sealant is chosen because it moves without pulling hard at the edges. That protects surfaces like brick, render and concrete. Too stiff a sealant can pull at the edges and break them. Where a wall is exposed, as many are in small places like High Cross, wind-driven rain gets into any failed joint, and older walls, once damp, take a long time to dry.
What it costs depends on the size of the job, how much old material has to come out and access to the work. You’ll have a clear quote before any work starts, so you know where you stand.
What you get with us
- White, clear, grey or coloured to suit, where the product allows
- An ARBOMaster approved applicator
- Full insurance on every job
- Rated 4.9 stars on Google
Read how sealant jobs are priced or our reviews.
How it works
Good joint work is mostly preparation, and we do not rush it. Every joint is cleaned and dried before new material goes in. All told, the work takes anything from a few hours to several days, depending on the building. In a small place like High Cross, access is normally the main thing to plan. For outside work, also let us know about exposed walls and any outbuildings involved.
- First we look over the joints with you, agree which to renew and talk through access.
- We cut out the failed sealant and rake out any dirt or growth.
- We clean both faces of the joint and prime them where the product calls for it.
- Closed-cell backing rod is fitted to set the depth and stop three-sided bonding.
- The new sealant, chosen to suit the brick or render, is applied and tooled to a neat finish.
How to prepare
- Where the joints are inside, avoid wetting them before we arrive
- Mention any leaks or damp you’ve noticed
- Let us know about earlier repairs to the joints
How to get a quote
For a quote, call 0345 464 0079 or drop us an email with the location and a short description of the problem. You’ll have a clear quote before any work starts.
Read more
Walls and rooflines in High Cross
Rainfall in the South East is lower than in much of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind. Historic houses like Much Hadham Palace (about 4.2 miles east) are a reminder that the area around High Cross has older buildings as well as new. Where a home is older, older brick and stone need a sealant that suits them, at the right joint depth.
Managing a site like Thundridge Church of England Primary School? Then larger buildings have long runs of movement joint that eventually need resealing. If you let a flat or house near Ware station, failed wall and movement joints let damp in, so they’re worth checking between tenancies.
High Cross is about 2 miles north of Ware, in Hertfordshire. Jobs in High Cross get the same care as everywhere else we work: old sealant removed completely, careful preparation and a 12-month guarantee. 381 places in Hertfordshire are on our list, large and small. There’s also a page for Chelmsford, about 23 miles away.
Our applicators cover all of SG11 for external mastic. That includes homes and businesses on North Drive, Chestnut Grove and Poplar Close. If you are just outside High Cross, we cover Wadesmill (1 mile south-west), Standon Green End (1 mile north), Thundridge (1 mile south), Cold Christmas (1 mile south-east) and Barwick (1 mile north-east). We also work in nearby towns such as Stevenage (8 miles north-west), St Albans (15 miles south-west), Bishop's Stortford (8 miles east), Welwyn Garden City (8 miles south-west), Harpenden (14 miles west) and Hitchin (13 miles north-west).
What’s near High Cross
Locally, jobs take us to homes and businesses close to The White Horse Inn and the streets around them. The closest station to High Cross is Ware station, about 2.8 miles south of the centre. Other landmarks nearby include Museum of Street Lighting (3.4 miles south) and Hertford County Hospital (4.6 miles south-west). The countryside around High Cross includes King's Meads.
Also near High Cross
More services for High Cross
Signs you need external mastic in High Cross
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 normally contact us after spotting something like this:
- Leaking joints around cladding and façade panels
- Rigid filler in a joint that should flex
- Gaps where render, brick and frames meet
- Rain getting behind render or cladding at a joint
If you live in an older home near Church of St John the Evangelist, the joints between older walls, newer extensions and the roofline need a sealant that can move.
Before you book anyone
- What product goes in the joint
- What preparation is included
- Whether they seal over old material or remove it
- Is VAT in the price?
What we can’t put right
In fairness, some problems need a different trade:
- Damp from another source, such as a leaking gutter or a bridged damp-proof course
- Cutting new joints into brickwork, which is building work rather than sealant work
- Cracks in the bricks or render themselves, away from the joints
Not sure which it is? You can ring 0345 464 0079 or drop us an email and we’ll tell you honestly.
What we seal
- Copings & trims
- Joints between brick and frames
- Concrete & block
- Brickwork movement joints
- Façade panels
- Render & cladding joints
Your questions about external mastic in High Cross
Do you work for landlords with property near Ware station?
Yes, rental work is part of what we do. Just phone 0345 464 0079 or drop us an email and tell us about the property, and we will give you a clear price.
Can you do external mastic in High Cross?
Yes, High Cross is within the area we cover. Our work covers London and the South East. You can ring 0345 464 0079 or drop us an email and let us know what needs doing, and we’ll give you a clear quote.
How long does external mastic take?
It depends on the size of the job, but as a guide it takes anything from a few hours to several days, depending on the building. We’ll give you a better idea when we quote.
Does someone need to be in?
That depends on where the joints are. Inside work needs someone to give us access, and for outside work we’ll agree access with you when we book.
Can you seal joints between render and window frames?
Yes. The old joint is removed, both surfaces cleaned and primed where needed, and a flexible sealant applied. We pick a colour that works with both materials.
Do you work for hotels and businesses?
Yes, regularly. We can plan bigger jobs in stages to suit the site.
What sealant do you use?
The product depends on the job: anti-fungal sanitary silicone in wet areas, and other sealants where joints move or face the weather. Brands we use include Arbo and Everbuild.
What do you need from me for a quote?
Let us know what needs doing and where, plus pictures if you have them. If we need more, we will ask.