Hertfordshire · England
Ayot St Lawrence External Mastic
Sealing brickwork movement joints, render, cladding and façade joints in Ayot St Lawrence, with a one-year guarantee on every job. Call for a quick quote.
- Failed sealant between panels on a façade
- Joints pointed up with cement by mistake
- Weathered mastic that no longer stretches
Keeping the joints in good condition
To keep the joints looking good and working properly:
- Don’t let climbing plants root in the sealant
- Act on the first splits you see
- Deal with leaking gutters that soak the joints below
- Show decorators and builders where the movement joints are
If you have more work done on the wall, such as new render, cladding or an opening, show the contractor the movement joints. They must stay as flexible joints, never rendered or pointed over.
If you can see gaps, plants or bare sections in a joint, have it checked. Earlier resealing means a smaller job and a better result.
External mastic for homes and businesses in Ayot St Lawrence
On houses, flats and commercial buildings across Ayot St Lawrence, we reseal joints in brickwork, render, cladding and façade panels. The preparation is the same whatever the wall: clean joint faces and the right depth. We are often asked to deal with plants rooting in failed movement joints and hard, crazed mastic that has stopped moving, on copings & trims, concrete & block and façade panels.
Around Ayot St Lawrence, older buildings can be stone, brick or timber-framed, many with extensions added later. Where one material meets another is where water generally gets in, and they need the right sealant at the right depth.
You’re covered for a year from the day we finish. If anything is not right with it, ring 0345 464 0079 or email us.
- Location
- Ayot St Lawrence (AL6)
- Region
- Hertfordshire
- Guarantee
- One year on every job
- Quotes
- A clear price before we start
- Call
- 0345 464 0079
- Updated
- 26 October 2026
Common problems we fix in Ayot St Lawrence
Using the wrong sealant is another common reason. A stiff, general-purpose sealant can’t cope with a joint that moves a lot, and it tears off the sides.
These are the problems we’re asked about most:
- Hard, crazed mastic that has stopped moving
- Plants rooting in failed movement joints
- Movement joints filled with mortar instead of sealant
- Rain getting behind render or cladding at a joint
Rented homes near Welwyn North station change hands often, and split movement joints are easy to miss on a rental until damp shows inside.
Questions to ask before you book
- What happens if the job turns out different
- Which sealant they’ll use, and why
- Who turns up on the day
- Whether they’re fully insured
For landlords and businesses
A neglected joint can let water reach the structure, which matters even more when someone else lives there. Keeping joints in good order is simple maintenance.
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.
Quotes for external mastic in Ayot St Lawrence
The price is agreed before any work begins. It’s based on:
- Access and height
- Mould in or behind the old joints
- The type of sealant required
- Working hours on commercial sites
There are no prices on our website, because each job is priced on what it involves. For a quick quote, please ring 0345 464 0079 or email us.
What we need to know
Photos by email are helpful but not essential. Please mention:
- The address or postcode of the job
- The type of property
- If someone has resealed it before
- How we’d reach the joints
Getting a quote is simple: tell us what needs doing and where and its rough size. A few photos by email make the job easier to understand, and we will come back to you with a quote.
What external mastic looks like in Ayot St Lawrence
With historic houses such as Shaw's Corner (about 0.2 miles south-west) nearby, there’s older building stock in the area around Ayot St Lawrence as well as newer homes. 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, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
Managing a site like Monk's Walk School? Then its movement joints, gutters and trims need looking after like any other building’s. Homes close to Old St Lawrence Church include some older properties, and an extension built onto an older house moves differently, and the joint between them takes the strain.
Ayot St Lawrence is about 4 miles east of Harpenden, in Hertfordshire. Whether you’re in the middle of Ayot St Lawrence or further out, external mastic is available for homes and businesses alike, from flats and houses to offices and hotels. Across Hertfordshire, we cover 381 places, Ayot St Lawrence among them. For nearby work, see our London page.
All of AL6 is within our area for external mastic. External mastic is available to properties on Hill Farm Lane and Bibbs Hall Lane. Nearby, we also carry out external mastic in Codicote Bottom (1 mile north-east), Ayot St Peter (1 mile south-east), Gustard Wood (1 mile south-west), Codicote (1 mile north-east) and Kimpton (2 miles north-west). We also work in nearby towns such as Watford (13 miles south-west), Hemel Hempstead (10 miles south-west), Stevenage (6 miles north-east), St Albans (6 miles south-west), Welwyn Garden City (4 miles south-east) and Harpenden (4 miles west).
Local landmarks in Ayot St Lawrence
Around Ayot St Lawrence, our work takes us to homes and buildings near The Brocket Arms and Danesbury Park and the streets around them. The nearest railway station is Welwyn North station, roughly 3.1 miles east of the centre. Other landmarks nearby include Queen Elizabeth II Hospital (4.9 miles south-east) and Howard Centre (3.5 miles south-east). Not far away are Stocking Springs Wood.
FAQs for Ayot St Lawrence
Can you help a landlord with a rental near Welwyn North station?
Yes, rental work is part of what we do. Just ring 0345 464 0079 or drop us an email and tell us about the property, and we’ll give you a clear price.
Is Ayot St Lawrence within the area you cover?
Yes, we do. 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 will you be here?
That depends on how much there is to do, but most jobs take a few hours for a handful of joints, longer for a whole elevation. We will tell you when we quote.
When is the sealant fully cured?
Cure times vary by product and the conditions. Before we leave, we’ll tell you the cure time.
Do you take out the old sealant first?
Yes, always, and completely. New sealant will not bond properly to old, so any old material comes out before anything new goes in.
Do you hold any approvals?
Yes. We’re approved under the ARBOMaster scheme, which is run for the Arbo sealant brand.
Do I have to be there?
That depends on where the joints are. Inside work needs someone to give us access, and for outside work we will agree access with you when we book.
Will it make a mess?
No. The area is protected while we work and cleaned up afterwards.
Why it’s worth doing now in Ayot St Lawrence
Water gets in through a failed movement joint. Dealing with it early keeps the repair to the joint, instead of the wall and finishes around it. Around Ayot St Lawrence, older homes often have timber in their floors and frames, and water through a failed joint can rot timber if it’s left.
Homes and businesses are quoted the same way: how much there is to do, how we reach it and what it needs, along with when we can work on site. Ask us for a quote and we will go through it with you.
Why Ayot St Lawrence clients choose us
- 4.9 on Google from 180+ five-star reviews
- We are fully insured
- Experience in homes, commercial sites and hotels
- Every job guaranteed for a year
Take a look at what affects the cost and customer reviews.
Also near Ayot St Lawrence
More services for Ayot St Lawrence
What happens on the day
The work is kept neat and contained to the area we’re working on. The job usually takes a few hours to a few days, depending on the length of joint and the access, and we tell you how long to leave it before we go. In a small place like Ayot St Lawrence, access is generally 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.
- 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.
- 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.
Preparing for the visit
- Where the joints are inside, avoid wetting them before we arrive
- Let us know about earlier repairs to the joints
- Clear items away from the joints we’re working on
Ask for a quote
Call for a quick quote, or send an email if you’d rather. Describe what needs sealing and we will talk you through the work.
Related advice
Can I do it myself?
Not every job suits DIY: high-level joints, fire-rated gaps, external movement joints and big jobs need the right product, the right access and the right method.
A careful DIYer can reseal a simple joint, like a short, easy-to-reach joint indoors. The common mistakes are sealing over old sealant, sealing a damp joint and using far too much.