Hertfordshire · England
External & façade joints in Throcking, Hertfordshire
We cover Throcking for sealing brickwork movement joints, render, cladding and façade joints. Old material cut out, joints cleaned and sealed neatly and every job guaranteed for a year.
- Plants rooting in failed movement joints
- Failed seals between different materials
- Failed sealant between panels on a façade
External mastic in Throcking, done properly
Getting the depth right is half the job. 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. We are often asked to deal with brick movement joints where the sealant has split and sealant that has lost its bond to the brick or render, across render & cladding joints, joints between brick and frames and concrete & block.
Older homes in small places like Throcking may be stone, brick or timber-framed, often with later extensions. The joints where those materials meet are the weak points, and they need the right sealant at the right depth.
Our work is backed for twelve months, and the guarantee is the same wherever you are.
- Where
- Throcking (SG9)
- Region
- Hertfordshire
- Guarantee
- 12 months on all our work
- Quote
- A clear price before any work starts
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
Questions from Throcking
Is Throcking in your area for external mastic?
Yes. We work across London and the South East, and Throcking is part of that. You can phone 0345 464 0079 or drop us an email and tell us what needs doing.
Will you come out to Throcking?
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 you match the colour of my brickwork?
There’s a good range of exterior colours, including greys, browns, whites and stone tones. We pick the one that suits your wall best so it doesn’t stand out.
Should I try DIY first?
That depends on the joint. High-level, external movement and fire-rated joints are professional jobs, while a short indoor joint may be within reach.
Is it OK to fill a movement joint with cement?
No. Rigid materials cannot move with the wall, so the joint stops doing its job. Where a joint has been mortared, it can often be raked out and sealed properly.
Does someone need to be in?
Access is agreed with you when the job is booked. For inside work, that normally means someone being in.
When is the sealant fully cured?
Different products cure at different speeds, so please follow the time we give you when we finish.
Are you fully insured?
Yes. We are fully insured.
DIY sealant or a professional job?
If you’ve already had a go yourself, that’s fine. We remove it and do the joint properly, so tell us about it when you ask for a quote.
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.
Honest limits
To be straight with you, there are a few things sealant will not fix:
- Walls that need new movement joints cut into them
- Cracking across the wall rather than at a joint
- Loose or hollow render, which needs re-rendering
Not sure which it is? You can call 0345 464 0079 or send us an email and we will tell you honestly before booking.
Where we work in Throcking
- Concrete & block
- Copings & trims
- Joints between brick and frames
- Render & cladding joints
- Brickwork movement joints
- Façade panels
What we do, step by step
On the day, there’s very little for you to do. Show us the job and we’ll take it from there. The work itself takes anything from a few hours to several days, depending on the building from start to finish. Somewhere like Throcking needs a little journey planning: let us know about lanes, gates and parking. We bring what the job needs, so it can be finished in one trip where possible.
- Each joint is checked and the colour of the new sealant agreed.
- Failed sealant is removed back to clean, sound faces.
- Closed-cell backing rod is pushed in so the sealant bonds to two sides only.
- Primer is applied wherever the sealant needs it.
- We gun in low-modulus sealant and tool it neatly.
How to prepare
- Let us know if you’ve seen damp or leaks
- Where the joints are inside, avoid wetting them before we arrive
- Mention any tricky access
Get a quote
Asking for a quote is easy: let us know the job and the location. A few pictures by email make the job easier to understand, and we will take it from there.
Read more
Landlord and commercial work in Throcking
In hotels, rooms out of use cost money, so we plan the work room by room. Hotel work is part of what we do, alongside homes and businesses.
Whether it’s one flat or a portfolio, you get the same standard of work: the old material taken out, careful preparation and a 12-month guarantee.
How we quote for external mastic
We quote each job individually. These are the things that affect it:
- Any mould that needs treating
- When we can work, for business premises
- The product the joint needs
- How easy the joints are to reach
A failed joint rarely gets cheaper to fix by waiting, because water and mould keep working on it. If you are not sure whether it needs doing, call 0345 464 0079 or drop us an email for an honest opinion and a quote.
What we need to know
When you call or email, it’s useful to know:
- The problem you’ve noticed
- Any access issues, like height or stairs
- Whether it’s a home or a business
- Where the property is
Call for a quick quote, or email us if that is easier. Tell us about the joints that need doing and we’ll explain what’s involved and send you a clear quote.
What the job involves on each surface
Copings and trims
Coping and trim joints face rain and sun head on. Each is resealed with a weatherproof, flexible sealant.
Concrete and blockwork
Blockwork and concrete shrink over time and move with the seasons. Their movement joints are sealed over backing rod with a flexible sealant.
Also in Throcking
How to look after the new joints
Looking after new joints is easy:
- Deal with leaking gutters that soak the joints below
- Clear growth from the base of walls and joints
- Act on the first splits you see
- Tell anyone working on the walls about the movement joints
Only paint over the joint if we have confirmed the sealant can take paint. Many exterior sealants are not designed to be painted, and paint can crack as the joint moves.
Water getting behind cladding or render can go unnoticed for a long time. When it finally shows inside, the joint may have been open for years, so it’s worth resealing at the first signs.
Walls and rooflines in Throcking
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.
Managing a site like Freman College? Then larger buildings have long runs of movement joint that eventually need resealing. For an older house near a landmark such as Holy Trinity Church, old and new materials meet at the roofline and walls, which is where sealant earns its keep.
Throcking is about 6 miles north-east of Stevenage, in Hertfordshire. From the centre of Throcking to the outskirts, external mastic is available for homes and businesses alike, from flats and houses to offices and hotels. Throcking is one of 381 places in Hertfordshire where we work. Chelmsford is on our list too, around 28 miles away.
Every address in SG9 is covered for external mastic, from the main roads to the quietest streets. We also cover Cottered (1 mile south-west), Chipping (1 mile north-east), Buntingford (2 miles east), Aspenden (2 miles south-east) and Layston (2 miles east). We also work in nearby towns such as Stevenage (6 miles south-west), Bishop's Stortford (11 miles south-east), Welwyn Garden City (12 miles south-west), Hitchin (9 miles west), Hoddesdon (14 miles south) and Hatfield (15 miles south-west).
Landmarks near Throcking
Nearby you will also find Clothall Castle (4.1 miles west). Not far away are Hawkins Wood.