Hertfordshire · England
Burnham Green External Mastic
Our applicators work in Burnham Green on sealing brickwork movement joints, render, cladding and façade joints. Old sealant removed completely, joints prepared properly and a one-year guarantee.
- Water getting into walls through failed joints
- Joints pointed up with cement by mistake
- Joints with sealant missing in places
For landlords and businesses
Letting agents often deal with us directly. Send the address, what’s needed and the access arrangements and we will give you a quote.
Letting agents and landlords in Burnham Green can book us as well as householders. Resealing between tenancies keeps a property looking cared for before the next move-in.
External mastic in Burnham Green
Failed sealant is cut out, the depth set with closed-cell backing rod, and the joint resealed with a low-modulus sealant made for outside. We pick a colour that sits well with the wall so the line blends in. We work on façade panels, concrete & block and brickwork movement joints, and the jobs we see most are sealant that has lost its bond to the brick or render and plants rooting in failed movement joints.
In a village or hamlet like Burnham Green, older cottages and farm buildings often stand in the open, so walls and rooflines take the full force of wind and rain. Gutter joints and wall joints there need a sealant that can flex and stay put.
All our work comes with a one-year guarantee, wherever you are in Hertfordshire.
- Location
- Burnham Green (AL6)
- Region
- Hertfordshire
- Guarantee
- 12 months on all our work
- Price
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
What external mastic looks like in Burnham Green
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. Historic houses like Digswell House (about 1.9 miles south-west) are a reminder that the area around Burnham Green has older buildings as well as new. In older buildings, older walls and rooflines need a sealant that moves with them and suits the material.
For landlords with property near Welwyn North station, failed wall and movement joints let damp in, so they’re worth checking between tenancies. Digswell House, about 1.9 miles south-west, is one of the historic houses in the wider area around Burnham Green, and older homes nearby need a sealant that suits their walls.
Burnham Green is about 3 miles north-east of Welwyn Garden City, in Hertfordshire. Burnham Green gets the same service as everywhere we cover: the old material taken out, joints prepared properly and a 12-month guarantee. Our Hertfordshire coverage runs to 381 places, and Burnham Green is one of them. For nearby work, see our London page.
Here we cover the AL6 postcode area for external mastic. We cover properties on Burnham Close, Burgess Close and Burnham Green Road and the roads around them. Neighbouring places we cover for external mastic include Tewin Wood (1 mile south-east), Harmer Green (1 mile west), Bull's Green (1 mile north-east), Tewin (1 mile south-east) and Oaklands (1 mile north-west). Larger places within reach include Watford (15 miles south-west), Hemel Hempstead (14 miles south-west), Stevenage (5 miles north), St Albans (9 miles south-west), Bishop's Stortford (14 miles east) and Welwyn Garden City (3 miles south-west).
Around Burnham Green
In Burnham Green, that means homes and buildings near Belmont pub, among other places. The nearest railway station is Welwyn North station, roughly 1.2 miles south-west. Nearby you will also find Datchworth Museum (1.1 miles north) and Queen Elizabeth II Hospital (3.6 miles south). Not far away are Tewin Orchard and Hopkyns Wood.
DIY versus a professional finish
Some jobs are best left to a professional: high-level joints, fire-rated gaps, external movement joints and big jobs call for the right materials, safe access and experience.
Overfilling a joint is a classic DIY mistake. A heavy bead looks messy and copes badly with movement, and getting the depth right matters as much as the look.
Why deal with it now?
Pointing a movement joint with mortar might seem a neat fix, but it stops the joint moving. The movement then cracks the brickwork or render nearby. A flexible sealant over backing rod is what the joint needs. Older cottages and farmhouses around Burnham Green can have timber floors and frames, where water from a failed joint can cause rot if it’s left.
Rather than a set price list, we look at what your job involves: the amount of work, the old material and the access. You will know the price before we begin.
Why Burnham Green clients choose us
- Arbo and Everbuild products
- 180+ five-star Google reviews
- White, clear, grey or another colour, product permitting
- Anti-fungal sanitary silicone in wet areas
Read our cost guide or our reviews.
What happens on the day
When we get to you, we check the joints match what you told us. If anything is different, we explain it before carrying on. Most jobs then take a few hours for a handful of joints, longer for a whole elevation. Somewhere like Burnham Green needs a little journey planning: tell us about narrow lanes, gates, long drives and where we can park. We bring what the job needs, so it can be finished in one trip where possible.
- We inspect the joints and agree which need resealing and how they’ll be reached.
- The old mastic and anything lodged in the joint is removed.
- Both sides are cleaned back to sound material and primed if needed.
- Closed-cell backing rod is fitted to set the depth and stop three-sided bonding.
- A flexible exterior sealant is applied and tooled in a colour to suit the wall.
Getting ready for the visit
- Mention any tricky access
- Let us know if you’ve seen damp or leaks
- Let us know about parking restrictions
How to get a quote
Want a quote for external mastic? Please phone 0345 464 0079 or send us an email with a few details. We’ll explain what we’d do and give you a clear price before work begins.
Advice
Signs you need external mastic in Burnham Green
UV, rain and frost all age exterior sealant. In time it goes hard, crazes on the surface and stops stretching, so the joint eventually tears or comes away from one side.
Common reasons people contact us include:
- Movement joints with cracked, split or missing sealant
- Water getting into walls through failed joints
- Gaps where render, brick and frames meet
- Failed sealant between panels on a façade
Schools such as Monk's Walk School are buildings too, and movement joints, cladding joints and gutters on larger buildings need the same care as a house’s.
What to look for in a quote
- Who does the work, and how experienced they are
- Is VAT in the price?
- How the colour is chosen
- What happens if the job turns out different
Places near Burnham Green
Other services in Burnham Green
Burnham Green: your questions answered
Do you cover Burnham Green for external mastic?
Yes, Burnham Green is within the area we cover. Our work covers London and the South East. Just call 0345 464 0079 or email us with a few details of the job, and we will send you a clear quote.
Is Burnham Green within the area you cover?
Yes, Burnham Green is covered. Our work covers London and the South East, from towns to the smallest places. The journey is planned ahead, so it helps to know about access.
How long should I leave it?
That depends on the sealant used, so follow the cure time we give you.
Do you remove the old sealant?
Yes. We cut out all the old sealant and clean the joint before resealing.
Do I have to be there?
Access is agreed with you when the job is booked. For inside work, that normally means someone being in.
Do you work for letting agents?
Yes, often. Several properties can be quoted together, and between tenancies is a good time for the work.
Can you match the colour of my brickwork?
The aim is a neat, even joint in a colour that suits the wall. Colour is agreed with you before we begin, matched as closely as the range allows.
I rent my home. Can I book you?
Of course. Ask your landlord first, and we can send them the quote if that helps.
How to look after the new joints
No joint lasts for ever, but care makes a real difference. A few tips:
- Check external joints each spring
- Keep water from gutters off the wall
- Wash walls gently around the sealant
- Check the sealant is paintable before painting near it
Look over the joints once a year, ideally after winter. Watch for splits, edges coming away or growth in the joint.
Act while the splits are small. At that stage it’s a simple cut out and reseal.
What the job involves on each surface
Render joints
The face of render can be soft, so a low-modulus sealant is kinder to the joint edges. Priming is done where the sealant calls for it.
Cladding and façade panels
Metal and composite panels move a lot with temperature, so the joints work hard every day. We choose the product to suit.