Hertfordshire · England
Sacombe External Mastic
Sealing brickwork movement joints, render, cladding and façade joints for homeowners, landlords and businesses in Sacombe. ARBOMaster approved applicators, fully insured, with a 12-month guarantee.
- Failed seals between different materials
- Movement joints with cracked, split or missing sealant
- Rain getting behind render or cladding at a joint
How to look after the new joints
Joint life depends on how it’s used and looked after. We suggest:
- Never let anyone fill a movement joint with mortar
- Don’t let climbing plants root in the sealant
- Act on the first splits you see
- Ask before painting over external sealant
Keep the joints clear of soil, plants and climbing growth. Anything that holds water against the joint wears it out sooner.
Small splits are the time to act. Then it’s a straightforward cut-out and reseal.
External mastic in Sacombe, done properly
Movement joints let brickwork, render and cladding expand and shrink without cracking. The sealant in it has to stretch and squeeze for years, and when it fails, the wall takes the strain and water finds a way in. We work on copings & trims, joints between brick and frames and brickwork movement joints, and common reasons people get in touch are rigid filler in a joint that should flex and panel joints letting water in.
Outside joints can only be sealed when they’re dry, so work in Sacombe is booked around the forecast. Let us know about access to every wall, plus any garages or outbuildings.
The work is covered for a year after we finish. If anything isn’t right with it, ring 0345 464 0079 or send us an email.
- Where
- Sacombe (SG12)
- Region
- Hertfordshire
- Guarantee
- A year, on every job
- Quotes
- A clear price before work begins
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
Should I try it myself first?
Sealing over old silicone is the commonest DIY error. Silicone doesn’t stick to old silicone, so it peels away and traps moisture behind it. Everything old must be removed first.
If you are set on DIY, put the effort into preparation: take out all the old sealant, make sure the joint is clean and dry, and give it the full cure time. If it fails, we can still redo it.
Quotes for external mastic in Sacombe
Call for a quick quote. What matters most is:
- Mould in or behind the old joints
- The amount of work
- The number of rooms or windows
- Which sealant suits the joint
There are no prices on our website, because the cost depends so much on the job itself. Call for a quick quote.
What to tell us for a quote
To make quoting easier, please include:
- Any access issues, like height or stairs
- Whether it’s a home or a business
- The rough size of the job
- Any previous sealing or DIY work
For a quick quote, get us on the phone, or send an email if you’d rather. Describe what needs sealing and we will talk you through the work and give you a clear price.
FAQs for Sacombe
Is Sacombe in your area for external mastic?
Yes, Sacombe is within the area we cover. Our work covers London and the South East. Just phone 0345 464 0079 or send us an email with a few details of the job.
I let a flat near Watton-At-Stone station. Can you help?
Yes. We work for landlords and agents as well as homeowners, and several properties can go on one quote. Just phone 0345 464 0079 or drop us an email with the address and what needs doing, and we’ll send you a clear quote.
Where are you based?
We work from Crawley. Our applicators cover Sacombe.
Will it make a mess?
Very little: the area around the joints is protected first, and we clear up the old sealant and our materials before we leave.
Are you insured?
Yes. We are fully insured, and we can confirm the details when we quote.
Are you ARBOMaster approved?
Yes. We hold ARBOMaster approved applicator status, and we’re fully insured.
Can you seal joints between two different materials?
Yes. We cut out the old sealant, prepare both faces and reseal with a flexible exterior product. The colour is chosen to suit.
Will there be a smell?
Some sealants have a smell while they cure. Ventilation helps.
What we cannot put right
To be straight with you, some problems need a different trade:
- Cracks in the bricks or render themselves, away from the joints
- Adding movement joints to masonry that has none
- Failed render or damaged cladding panels
Not sure which it is? You can ring 0345 464 0079 or send us an email and we will tell you honestly.
What we seal
- Copings & trims
- Façade panels
- Render & cladding joints
- Brickwork movement joints
- Concrete & block
- Joints between brick and frames
Surface by surface
Copings and trims
Coping joints that leak let water straight down into the wall. Resealing them is a small job that protects a lot.
Joints between dissimilar materials
Where a frame or panel meets masonry, water often finds a way in. We cut out the old sealant and reseal with a product suited to both surfaces.
Places near Sacombe
What else we do in Sacombe
For landlords and businesses
Letting agents and landlords in Sacombe can book us as well as householders. Sealant work between tenants is a simple way to keep a property in good order.
Whether it’s one flat or a portfolio, the work is the same standard: old sealant fully removed, joints prepared properly and a 12-month guarantee.
What we do, step by step
All our tools and materials come with us in the van, so there’s nothing for you to buy. After a quick look at the joints together, we protect the area and start. Most jobs take a few hours for a handful of joints, longer for a whole elevation. In a small place like Sacombe, access is normally 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.
- The old mastic and anything lodged in the joint is removed.
- The joint faces are cleaned and primed where the sealant needs it.
- Closed-cell backing rod is fitted to set the depth and stop three-sided bonding.
- We gun in a flexible exterior sealant in a colour that suits the wall and tool it neatly.
Preparing for the visit
- On commercial sites, let us know about site rules
- Clear items away from the joints we are working on
- Let us know about parking restrictions
Get a quote
The more we know about the job, the more useful the quote. Let us know the location, the problem and roughly how many joints, and email photos if that is easy.
Related advice
Walls and rooflines in Sacombe
With historic houses such as Aston Bury (about 3.7 miles west) nearby, there’s older building stock in the area around Sacombe as well as newer homes. In older buildings, older brick and stone need a sealant that suits them, at the right joint depth. The South East is one of the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
If you live in an older home near Church of St Katherine, the joints between older walls, newer extensions and the roofline need a sealant that can move. Letting a property close to Watton-At-Stone station? Then outside joints that have cracked can let damp into a rental, so check them between lets.
Sacombe is about 3 miles north-west of Ware, in Hertfordshire. From the centre of Sacombe to the outskirts, external mastic is available for homes and businesses alike, from flats and houses to offices and hotels. Our area takes in 381 places across Hertfordshire, large and small. For nearby work, see our London page, about 25 miles away.
Here we cover the SG12 postcode area for external mastic. If you are just outside Sacombe, we cover Sacombe Green (1 mile east), Dane End (1 mile north), Whempstead (1 mile north-west), Tonwell (1 mile south) and Standon Green End (2 miles east). Larger places within reach include Stevenage (6 miles north-west), St Albans (13 miles south-west), Bishop's Stortford (10 miles east), Welwyn Garden City (7 miles south-west), Harpenden (12 miles west) and Hitchin (11 miles north-west).
Landmarks near Sacombe
For rail, the closest station is Watton-At-Stone station, roughly 2.3 miles west of the centre. A little further out are Hertford Railway Museum (3.6 miles south) and Benington Castle (3.4 miles north-west). Green spaces nearby include Astonbury Wood.