Hertfordshire · England
External Mastic in Wyddial
External mastic for Wyddial, by sealant specialists with 20+ years’ experience. Rated 4.9 on Google from 180+ five-star reviews.
- Failed seals between different materials
- Joints with sealant missing in places
- Plants rooting in failed movement joints
When to call us in Wyddial
A lot of failed joints come down to preparation: dusty or wet faces, no primer where one was needed, or old sealant left in. The sealant never bonds properly.
These are the problems we’re asked about most:
- Failed sealant between panels on a façade
- Old sealant gone brittle and cracked
- Movement joints with cracked, split or missing sealant
- Plants rooting in failed movement joints
Managing a site like Layston Church of England First School? Then larger buildings have long runs of movement joint that eventually need resealing.
Questions to ask before you book
- How long to leave it before use
- What happens if the job turns out different
- What insurance they hold
- Is the old sealant removed completely?
How we handle external mastic in Wyddial
Where two different materials meet, such as brick and render or blockwork and metal, they move at different rates. A flexible exterior sealant takes up that movement where mortar or filler would crack. Common call-outs are for sealant that has lost its bond to the brick or render and water getting into walls through failed joints, across brickwork movement joints, render & cladding joints and joints between brick and frames.
Somewhere as small as Wyddial, homes and farm buildings often face open ground, so walls and rooflines take the full force of wind and rain. Joints on those walls need a sealant that moves with the building and stays in place.
Big or small, it’s backed by our 12-month guarantee in Wyddial and across Hertfordshire.
- Where
- Wyddial (SG9)
- Region
- Hertfordshire
- Cover
- A year, on every job
- Quote
- A clear quote up front
- Phone
- 0345 464 0079
- Updated
- 26 October 2026
What we cannot put right
To be straight with you, there are a few things sealant will not fix:
- Loose or hollow render, which needs re-rendering
- Cracks in the bricks or render themselves, away from the joints
- Structural movement, which needs a surveyor or engineer
If in doubt, ring 0345 464 0079 or drop us an email and we will say what we think before you book.
Surfaces we seal
- Joints between brick and frames
- Brickwork movement joints
- Copings & trims
- Façade panels
- Render & cladding joints
- Concrete & block
What external mastic looks like in Wyddial
Rainfall in the South East is lower than in much of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
If you live in an older home near Church of St Giles, an extension built onto an older house moves differently, and the joint between them takes the strain.
Wyddial is in Hertfordshire. For external mastic in and around Wyddial, please call 0345 464 0079 or drop us an email for a quick quote. We’re based in Crawley and cover Hertfordshire. We cover 381 towns and villages across Hertfordshire, from the larger towns to small villages. We also work in Chelmsford, about 26 miles from Wyddial.
All of SG9 is covered for external mastic, from the main roads to the quietest streets. If you need external mastic at a property on Cherry Orchard Lane and Moles Lane or a nearby road, we can help. Close by, we work in Layston (1 mile south), Chipping (1 mile west), Buntingford (1 mile south-west), Buckland (2 miles north-west) and Great Hormead (2 miles south-east). Further out, we also cover Stevenage (9 miles south-west), Bishop's Stortford (10 miles south-east), Welwyn Garden City (14 miles south-west), Hitchin (11 miles west), Hoddesdon (14 miles south) and Hertford (12 miles south).
What’s near Wyddial
Typical jobs here are in homes near Freman College, among other places. Nearby you’ll also find Anstey Hales Farm (2.6 miles east). Not far away are Hawkins Wood.
Nearby places to Wyddial
Also in Wyddial
Why it’s worth doing now in Wyddial
A properly done movement joint is an even line in a colour that suits the wall. A hurried job with smeared edges and no backing looks worse and fails sooner so it’s worth doing right. In a small place like Wyddial, homes can be exposed to wind and rain, which finds any gap, and older walls, once damp, take a long time to dry.
Commercial jobs are quoted on the same basis as homes: the amount of work, the access and the products needed, plus any working-time requirements on site. Ask us for a quote and we’ll go through it with you.
Why book with us
- Neat joints and a tidy finish
- Homes, businesses and hotels
- A sealant colour to suit the surroundings
- We never seal over old sealant
Read our cost guide or customer reviews.
What we do, step by step
There isn’t much for you to do on the day. Point us to the joints and we’ll get on with it. The work itself takes a few hours to a few days, depending on the length of joint and the access from start to finish. For a village or hamlet like Wyddial, the journey is planned in advance: let us know about lanes, gates and parking. Everything for the job comes with us, so a second trip is avoided where possible.
- 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.
- Backing rod goes in next, setting the depth and keeping the sealant off the back of the joint.
- The new sealant, chosen to suit the brick or render, is applied and tooled to a neat finish.
Getting ready for the visit
- Mention if the joints have been sealed before
- Keep children and pets away from the work area
- Tell us if parking is tricky
Ask for a quote
For a quick quote, get us on the phone, or email us if that is easier. Tell us about the joints that need doing and we will talk you through the work and give you a clear price.
Read more
How we quote for external mastic
Jobs vary more than people expect. What affects the quote:
- How much there is to do
- Any working-time requirements on site
- The product the joint needs
- Access and height
There are no prices on our website, because each job is priced on what it involves. Call for a quick quote.
Asking for a quote
You do not need to know the technical terms. It helps if you can tell us:
- The type of property
- A few pictures by email, if you can
- What’s wrong with the joints now
- If someone has resealed it before
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’s easy.
Work for landlords, hotels and businesses
Water getting past a failed joint can damage the building, which matters even more when someone else lives there. Keeping joints in good order is simple maintenance that we can handle for you.
If you manage several properties in or around Wyddial, several properties can be quoted together. Send us the addresses and the work at each, and photos by email help.
FAQs for Wyddial
Is there a guarantee on external mastic in Wyddial?
All our work, in Wyddial and everywhere else, comes with a 12-month guarantee. We are also fully insured and ARBOMaster approved.
Do you cover smaller places like Wyddial?
Yes, Wyddial is covered. We work across London and the South East, from towns to the smallest places. The journey is planned ahead, so it helps to know about access.
Should I try DIY first?
For a simple, easy-to-reach joint, a careful DIYer can do a reasonable job. The usual mistakes are sealing over old sealant, sealing a damp joint and using too much.
How long does external mastic last?
That depends on the wall, the weather and the movement. Signs to watch for are cracking, hardening and gaps at the edges, and reseal at that point.
Can a movement joint be filled with mortar?
No. A mortar-filled joint cannot move, so the movement cracks the wall elsewhere. Use a flexible sealant with backing rod.
Can you reach joints on upper floors?
It depends on the building. Send us pictures and a rough idea of the height.
Can you work on commercial sites?
Yes. We work in offices, washrooms, hotels and other commercial premises. We can talk about working times when we quote.
Which products do you use?
Products from Arbo and Everbuild, among others, picked for each joint. We explain the product when we quote.
Different surfaces, different methods
Copings and trims
Joints in copings, parapets and trims are exposed to the worst of the weather. We reseal them with an exterior sealant suited to the material.
Concrete and blockwork
Concrete faces can be dusty and porous, so preparation is key. A primer goes on where the product requires one.