Hertfordshire · England
Startop's End External Mastic
Movement joints in Startop's End need attention? We remove the old material, prepare the joints and seal them properly, and the work is guaranteed for a year.
- Panel joints letting water in
- Gaps where render, brick and frames meet
- Joints pointed up with cement by mistake
External mastic in Startop's End
Failed sealant is cut out, the depth set with closed-cell backing rod, and the joint resealed with a low-modulus sealant made for outside. The colour is chosen to suit the brick or render. Common call-outs are for water getting into walls through failed joints and joints pointed up with cement by mistake, across render & cladding joints, concrete & block and joints between brick and frames.
In a village or hamlet like Startop's End, older cottages and farm buildings often stand in the open, where walls and rooflines take the weather head on. Joints on those walls need a sealant that moves with the building and stays in place.
All our work comes with a 12-month guarantee, wherever you are in Hertfordshire.
- Where
- Startop's End (HP23)
- Region
- Hertfordshire
- Guarantee
- A year, on every job
- Price
- Quoted before any work starts
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
Aftercare tips
No joint lasts for ever, but care makes a real difference. Our tips:
- Fix overflowing gutters above sealed joints
- Check the sealant is paintable before painting near it
- Avoid pressure-washing directly into sealant joints
- Never let anyone fill a movement joint with mortar
Follow the cure time we give you before the joint is knocked or disturbed. Most exterior sealants skin fast but take longer to cure right through.
Gaps, plants or missing sealant in a joint are worth getting looked at. Early work is quicker and leaves a better finish.
Landlord and commercial work in Startop's End
Hotels need rooms back in use, so the work can be planned room by room. Hotel work is part of what we do, alongside homes and businesses.
We also work for property managers and facilities teams. Several sites can be quoted together.
More services for Startop's End
What happens on the day
Every visit runs the same way: we look at the joints together, mask and protect the surrounding surfaces, do the work and clear up. Most jobs take a few hours to a few days, depending on the length of joint and the access. Somewhere as small as Startop's End, access is often the only tricky part. If the job is outside, mention outbuildings, exposed walls and how to reach them.
- We start by walking round the building and agreeing the joints and the access.
- We cut out the old mastic and rake out anything in the joint.
- The faces are brushed clean and primed where the product requires it.
- We fit closed-cell backing rod to control the depth.
- The exterior sealant is applied, tooled and checked along its length.
Preparing for the visit
- Try not to wet indoor joints just before the visit
- Plan for the work area to be out of bounds to pets and children
- Let us know about earlier repairs to the joints
Ask for a quote
If you’re in Startop's End and need external mastic, phone 0345 464 0079 or drop us an email. Tell us what the problem is and where, and you will get a clear quote before we start.
Advice
Startop's End: your questions answered
Is Startop's End in your area for external mastic?
Yes, Startop's End is within the area we cover. We work across London and the South East. You can ring 0345 464 0079 or drop us an email and let us know what needs doing.
I let a flat near Tring station. Can you help?
Yes, rental work is part of what we do. You can call 0345 464 0079 or drop us an email with the address and a few details, and we will give you a fixed price before work begins.
Is there a guarantee?
Yes, for a year. If anything isn’t right with the work within the year, let us know and we will sort it.
Do I need to be at home?
That depends on where the joints are. Inside work needs someone to give us access, while outside work can sometimes be arranged differently.
Will the old sealant be removed?
Always. Sealing over old sealant is the main reason resealing fails early, so we never do it.
Can a movement joint be filled with mortar?
No. Cement or mortar cannot stretch. If it has already been filled, we can usually cut it out and reseal it.
Can you quote for more than one area?
Yes. Tell us about everything you’d like done and you’ll get one quote.
How long will you be here?
That depends on the amount of work, but as a guide it takes a few hours for a handful of joints, longer for a whole elevation. We’ll tell you when we quote.
External mastic in Startop's End: local notes
Historic houses like Cholesbury Manor House (about 4.4 miles south) are a reminder that the area around Startop's End 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. Compared with the north and west, the South East gets less rain, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
Letting a property close to Tring station? Then outside joints that have cracked can let damp into a rental, so check them between lets. For site and facilities teams at buildings such as Marsworth Church of England Infant School, larger buildings have long runs of movement joint that eventually need resealing.
Startop's End is about 1 mile north of Tring, in Hertfordshire. We provide external mastic to homes and businesses in Startop's End. Our area takes in 381 places across Hertfordshire, large and small. There’s also a page for Oxford, roughly 25 miles from Startop's End.
Jobs for external mastic in HP23 is quoted and booked the same way as anywhere else. External mastic is available to properties on Watery Lane, Lukes Lea and Marsworth Wharf and the roads around them. Close by, we work in Marsworth (1 mile north-east), Tringford (1 mile south), Wilstone (1 mile west), Bulbourne (1 mile east) and Gubblecote (1 mile north-west). Larger places within reach include Hemel Hempstead (10 miles south-east), St Albans (15 miles east), Harpenden (14 miles east), Berkhamsted (6 miles south-east), Rickmansworth (15 miles south-east) and Chorleywood (14 miles south-east).
Near you in Startop's End
Around Startop's End, our work takes us to homes and buildings near The Angler's Retreat pub and Tring School, among other places. For rail, the closest station is Tring station, roughly 2.3 miles south-east. A little further out are Tindal Centre (5.8 miles west) and Pitstone Green Museum (1.5 miles north-east). Green spaces nearby include College Lake nature reserve and Ivinghoe Beacon.
How we quote for external mastic
The price is agreed before any work begins. It takes into account:
- How many areas need sealing
- The number and length of the joints
- How easy the joints are to reach
- The old material and how stubborn it is
We don’t show prices on the website, because the cost depends so much on the job itself. For a quick quote, please ring 0345 464 0079 or send us an email.
What to tell us for a quote
A few details help us give you an accurate quote. When you get in contact, it helps to mention:
- Whether it’s a home or a business
- What the problem is, such as mould, gaps, leaks or cracking
- Pictures of the joints, sent by email
- Whether it has been sealed before
Quotes start with a quick conversation. Tell us what’s wrong, where it is and how much there is, and we will talk you through what we’d do. When it suits you, phone 0345 464 0079 or send us an email.
What the job involves on each surface
Joints between dissimilar materials
Joints where frames, sills or panels meet the wall are common leak points. The old joint is removed and a sealant that bonds to both sides goes in.
Cladding and façade panels
Metal and composite panels move a lot with temperature, so the joints work hard every day. The sealant is chosen with that in mind.
Why it’s worth doing now in Startop's End
Resealing a run of joints in one go is generally better than patching one at a time. Joints of the same age tend to fail together and it means sorting access once. Around Startop's End, older homes often have timber in their floors and frames, and water through a failed joint can rot timber if it’s left.
Some things make a job bigger or smaller: the old material and how easily it comes out, any mould to treat, and whether the work is at height. Your quote takes all of that into account.
What you get with us
- White, clear, grey or coloured to suit, where the product allows
- Sanitary silicone with an anti-fungal additive in wet areas
- An ARBOMaster approved applicator
- Arbo and Everbuild products
Read what affects the cost and what customers say.
Do you need external mastic in Startop's End?
Every building moves. Clay bricks expand slightly over their life, concrete and block shrink, and everything moves with temperature and wet. All of that ends up in the joint sealant.
Keep an eye out for these signs:
- Moss and dirt in joints with no sealant left
- Movement joints with cracked, split or missing sealant
- Leaking joints around cladding and façade panels
- Sealant pulling away from one side of the joint
If you live in an older home near Church of All Saints, old and new materials meet at the roofline and walls, which is where sealant earns its keep.
What your quote should include
- Which sealant they’ll use, and why
- What the cure time is
- Are they insured?
- How the surfaces are prepared before sealing