Hertfordshire · England
External & façade joints in Great Wymondley, Hertfordshire
Sealing brickwork movement joints, render, cladding and façade joints for Great Wymondley, backed by a 12-month guarantee. Ask us for a quote.
- Joints with sealant missing in places
- Failed sealant between panels on a façade
- Weathered mastic that no longer stretches
External mastic for homes and businesses in Great Wymondley
A movement joint is only as good as its depth. Backing rod controls how deep the sealant goes and keeps it off the back of the joint, leaving it bonded to two faces so it can move with the wall. If you have hard, crazed mastic that has stopped moving and rigid filler in a joint that should flex, we can help, whatever the surface.
Older homes in small places like Great Wymondley may be stone, brick or timber-framed, often with later extensions. Where one material meets another is where water generally gets in, and they need the right sealant at the right depth.
We guarantee the work for a year. If something is not right with it in that time, tell us and we will put it right.
- Where
- Great Wymondley (SG4)
- Wider area
- Hertfordshire
- Cover
- A year, on every job
- Price
- A clear price before work begins
- Call
- 0345 464 0079
- Updated
- 26 October 2026
Can I do it myself?
Some sealant jobs are within reach of a careful DIYer, like a short, easy-to-reach joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
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.
What affects the cost of external mastic
We quote each job individually. This is what makes a difference:
- The old material and how stubborn it is
- Access and height
- How much there is to do
- The number of rooms or windows
Every job is a little different, so we quote each one individually. Size, access and the product the joint needs all make a difference, and we will explain the quote if you ask.
Helping us quote
What to tell us when you ask for a quote:
- Any previous sealing or DIY work
- How we’d reach the joints
- The problem you’ve noticed
- Where the job is, and your postcode
Call for a quick quote, or email us if that is easier. Describe what needs sealing and we’ll talk you through the work before giving you a price.
What we do, step by step
All our tools and materials come with us in the van, so there’s nothing for you to buy. After a quick look at the joints together, the area is protected and the work begins. It normally takes a few hours to a few days, depending on the length of joint and the access. Somewhere as small as Great Wymondley, access is often the only tricky part. For outside work, also let us know about exposed walls and any outbuildings involved.
- We start by checking each joint, agreeing the ones to redo and how we’ll reach them.
- 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.
Getting ready for the visit
- Tell us about any water getting in
- Tell us if parking is tricky
- Mention any tricky access
Get a quote
Asking for a quote is easy: let us know what needs doing and where. A few pictures by email make the job easier to understand.
Related advice
Do you need external mastic in Great Wymondley?
Using the wrong sealant is another common reason. A stiff, general-purpose sealant cannot cope with a joint that moves a lot, and it tears off the sides.
The most common problems we see are:
- Failed sealant between panels on a façade
- Gaps where render, brick and frames meet
- Moss and dirt in joints with no sealant left
- Water getting into walls through failed joints
Schools such as Wymondley Junior Mixed and Infant School are buildings too, and its movement joints, gutters and trims need looking after like any other building’s.
Questions to ask before you book
- What guarantee comes with the work
- Which colour the sealant will be
- What the cure time is
- Is VAT in the price?
FAQs for Great Wymondley
Do you work for landlords with property near Hitchin station?
Yes, we work for letting agents and landlords. Just phone 0345 464 0079 or email us and tell us about the property, and we’ll give you a clear quote.
Is Great Wymondley within the area you cover?
Yes, smaller places are covered as well as towns. Our work covers London and the South East. Just mention lanes, gates or anything else about the route when you book.
Can I add another job to the visit?
Yes. Tell us about everything you’d like done.
Is it OK to fill a movement joint with cement?
No. Rigid materials can’t move with the wall and the joint fails. If it has already been filled, we can normally cut it out and reseal it.
Will the old sealant be removed?
Yes. Sealing over the old bead is the commonest cause of early failure, and it’s something we never do.
Do you use backing rod?
Backing rod controls the sealant depth and keeps it off the back of the joint. That way it bonds to the two sides only and can stretch.
Do you do commercial work?
Yes. Hotels, offices and other businesses use us, and we’re fully insured.
How long before the joint can be used?
It depends on the product. We tell you how long to leave it before we go.
Also near Great Wymondley
What else we do in Great Wymondley
Landlords, agents and businesses in Great Wymondley
Letting agents often deal with us directly. Send the address, what’s needed and the access arrangements and we’ll give you a quote.
Whether it’s one flat or a portfolio, the work is the same standard: the old material taken out, careful preparation and a 12-month guarantee.
Walls and rooflines in Great Wymondley
Historic houses like Knebworth House (about 4.9 miles south) are a reminder that the area around Great Wymondley 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. London and the South East are among the drier parts of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
Rented homes near Hitchin station change hands often, and outside joints that have cracked can let damp into a rental, so check them between lets. For an older house near a landmark such as Church of St Mary the Virgin, the joints between older walls, newer extensions and the roofline need a sealant that can move.
Great Wymondley is about 2 miles east of Hitchin, in Hertfordshire. Every kind of property in Great Wymondley can book us for external mastic, old or new, large or small. The work is guaranteed for a year. Great Wymondley is one of 381 towns and villages in Hertfordshire we cover for external mastic. For nearby work, see our London page.
Work in SG4 is quoted and booked the same way as anywhere else. You’ll find streets such as Graveley Road, Hitchin Road and Arch Road, all of which we cover. Neighbouring places we cover for external mastic include Little Wymondley (1 mile south), Poets Estate (1 mile north-west), Graveley (1 mile south-east), Titmore Green (1 mile south) and Willian (1 mile north-east). Larger places within reach include Stevenage (3 miles south-east), St Albans (14 miles south), Welwyn Garden City (10 miles south), Harpenden (10 miles south-west), Hatfield (12 miles south) and Hertford (12 miles south-east).
Around Great Wymondley
Around Great Wymondley, our work takes us to homes and buildings near Hitchin Girls' School, The Green Man pub and Kingshott School, among other places. The nearest railway station is Hitchin station, roughly 1.4 miles north-west of the centre. Other landmarks nearby include North Hertfordshire Museum (2 miles west) and Lister Hospital (1.6 miles south-east). The countryside around Great Wymondley includes Purwell Ninesprings.
What the job involves on each surface
Concrete and blockwork
Big joints in concrete need careful depth control. We size the backing rod to the gap.
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.
When it isn’t the sealant
We will not take on work that will not last, so here’s what sealant can’t put right:
- Cracks in the bricks or render themselves, away from the joints
- Loose or hollow render, which needs re-rendering
- Adding movement joints to masonry that has none
Not sure which it is? You can call 0345 464 0079 or drop us an email and we will tell you honestly before you book.
Where we work in Great Wymondley
- Render & cladding joints
- Façade panels
- Joints between brick and frames
- Brickwork movement joints
- Copings & trims
- Concrete & block