Hertfordshire · England
External Mastic in Bernards Heath
External mastic for Bernards Heath and the surrounding area: the right sealant, proper preparation and a neat finish. Call for a quick quote.
- Sealant pulling away from one side of the joint
- Cracked joints where brick meets render or frames
- Water getting into walls through failed joints
About our external mastic in Bernards Heath
For buildings in Bernards Heath, we reseal external joints of all kinds, from brick movement joints to cladding panels. The preparation is the same whatever the wall: clean joint faces and the right depth. If you have joints with sealant missing in places and old sealant gone brittle and cracked, we can put it right, on concrete & block, joints between brick and frames and façade panels alike.
Homes around Bernards Heath range from older cottages to newer houses, with walls and rooflines of every type. Older homes need their gutter and trim joints kept tight, newer ones their movement joints.
We guarantee the work for a year. If something isn’t right with it in that time, tell us and we’ll put it right.
- Place
- Bernards Heath (AL3, AL1, AL4)
- Wider area
- Hertfordshire
- Cover
- A year, on every job
- Price
- Quoted before any work starts
- Call
- 0345 464 0079
- Updated
- 26 October 2026
Your questions about external mastic in Bernards Heath
Is Bernards Heath within the area you cover?
Yes, smaller places are covered as well as towns. Our work covers London and the South East. Let us know about access, parking and anything unusual about getting there when you book.
Can you help a landlord with a rental near St Albans station?
Yes, we work for landlords and agents. Just call 0345 464 0079 or email us and tell us about the property, and we’ll give you a clear price.
How long before the joint can be used?
Cure times vary by product and the temperature. Before we leave, we will tell you the cure time.
Is there a guarantee?
Yes. All our work carries a 12-month guarantee.
Is it OK to seal over old sealant?
No. The old sealant always comes out first.
How long does external mastic take?
It depends on the size of the job, but most jobs take a few hours for a handful of joints, longer for a whole elevation. We will give you a better idea when we quote.
Is it OK to fill a movement joint with cement?
No, not where the gap is a movement joint. Filling it with mortar defeats its purpose, and the wall may crack nearby. A flexible sealant is the right fill.
Can I add another job to the visit?
Yes. More than one area can go on one quote.
What happens on the day
At the end, we look at the finished work together. The work normally takes anything from a few hours to several days, depending on the building, depending on the amount of work. For a job in Bernards Heath, we agree the time, the access and parking before the day. Outdoor jobs depend on a dry day, since sealant needs a dry surface.
- We start by walking round the building and agreeing the joints and the access.
- Every bit of old sealant and any mortar or debris is cut out.
- Joint faces are cleaned back and primed if the sealant needs it.
- We fit closed-cell backing rod to control the depth.
- We apply the sealant, tool it and check the whole run.
Preparing for the visit
- Tell us about any previous sealing or DIY attempts
- Tell us about access, such as stairs, a lift or high-level joints
- Let us know if you’ve seen damp or leaks
How to get a quote
For a quick quote, get us on the phone, or send an email if you’d rather. Describe what needs sealing and we’ll talk you through the work.
Related advice
Surface by surface
Concrete and blockwork
Concrete and block walls shrink as they dry and move with temperature. Their movement joints are sealed over backing rod with a flexible sealant.
Cladding and façade panels
If the façade has a specified sealant, that is what we use, or one the system allows. Tell us what the building has when you get in touch.
Why it’s worth doing now in Bernards Heath
It often makes sense to reseal all the failing joints on an elevation together. Joints of the same age tend to fail together and it means sorting access once. In a smaller place like Bernards Heath, wherever a wall is exposed, a failed outside joint is a real source of damp. Inside, a split seal lets water into floors and panels just as it would anywhere.
Combining jobs into one visit is generally more efficient than separate visits, so tell us about everything that needs sealing. We’ll give you a clear quote for the lot.
Why us?
- You choose the colour before work begins
- We never seal over old sealant
- Domestic, commercial and hotel work
- 12-month guarantee on every job
See what affects the cost or our reviews.
Towns and villages near Bernards Heath
Also in Bernards Heath
Keeping the joints in good condition
After the cure time, these simple habits help:
- Look over the joints every year, ideally after winter
- Tell anyone working on the walls about the movement joints
- Keep movement joints as flexible joints, not mortar
- Leave the joints unpainted unless we’ve said otherwise
Follow the cure time we give you before the joint is knocked or disturbed. The surface skins over quickly, but full cure takes longer.
Water getting behind cladding or render can go unnoticed for a long time. By the time there’s a damp patch, the damage can be well established.
Signs you need external mastic in Bernards Heath
The wrong product in a moving joint is a classic cause. A high-modulus or general-purpose sealant can be too rigid for a busy joint, and it tears off the sides.
The most common problems we see are:
- Brick movement joints where the sealant has split
- Rigid filler in a joint that should flex
- Old sealant gone brittle and cracked
- Cracked joints where brick meets render or frames
Managing a site like Garden Fields Junior Mixed and Infant School? Then its movement joints, gutters and trims need looking after like any other building’s.
What your quote should include
- Are they insured?
- How the joint is cleaned and prepared
- Who does the work, and how experienced they are
- Whether you can choose the colour
When it isn’t the sealant
We will not take on work that won’t last, so these are the limits:
- Adding movement joints to masonry that has none
- Cracks in the bricks or render themselves, away from the joints
- Damp from another source, such as a leaking gutter or a bridged damp-proof course
If you’re not sure, just call 0345 464 0079 or drop us an email and we’ll give you a straight answer before you book.
Surfaces we seal
- Render & cladding joints
- Façade panels
- Copings & trims
- Brickwork movement joints
- Concrete & block
- Joints between brick and frames
Landlord and commercial work in Bernards Heath
We regularly work with letting and managing agents. Tell us the address, the job and how access works and we will quote.
Housing providers, facilities teams and property managers book us too. We can quote a run of properties together, and we are fully insured for the work.
What external mastic looks like in Bernards Heath
With historic houses such as Batchwood Hall (about 1 mile west) nearby, there’s older building stock in the area around Bernards Heath 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, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
If you let a flat or house near St Albans station, failed wall and movement joints let damp in, so they’re worth checking between tenancies. If you live in an older home near Church of St Saviour, old and new materials meet at the roofline and walls, which is where sealant earns its keep.
Bernards Heath is about 1 mile north of St Albans, in Hertfordshire. If you need external mastic in Bernards Heath, it’s easy to get a quote: please phone 0345 464 0079 or drop us an email. We’re based in Crawley and cover Hertfordshire, Bernards Heath included. Across Hertfordshire, we cover 381 places, Bernards Heath among them. You can also see our page for London, roughly 21 miles from Bernards Heath.
Jobs for external mastic in AL3, AL1 and AL4 is quoted and booked the same way as anywhere else. We cover properties on Etna Road, Green Lane and Manor Road. Main roads around Bernards Heath include the A1081. We also cover the places around Bernards Heath: St Albans (1 mile south), Marshalswick (1 mile east), St Stephens (1 mile south-west), Sopwell (2 miles south) and Childwick Green (2 miles north). Larger places within reach include Watford (7 miles south-west), Hemel Hempstead (5 miles west), Stevenage (12 miles north-east), Welwyn Garden City (7 miles north-east), Harpenden (4 miles north) and Hitchin (13 miles north).
Landmarks near Bernards Heath
Locally, jobs take us to homes and businesses close to St Albans Girls' School, Clarence Park and Jolly Sailor pub, among other places. The nearest railway station is St Albans station, about 0.8 miles south. A little further out are The Maltings (0.7 miles south) and St Albans Musical Museum (0.5 miles south-east). The countryside around Bernards Heath includes Verulamium Lake and The Wick Local Nature Reserve.