Hertfordshire · England
External Mastic in Radwell
Sealing brickwork movement joints, render, cladding and façade joints for householders, landlords and businesses in Radwell. ARBOMaster approved applicators, fully insured, with a 12-month guarantee.
- Damp patches traced to an open external joint
- Sealant pulling away from one side of the joint
- Old sealant gone brittle and cracked
For landlords and businesses
We work for landlords and agents as well as homeowners. Resealing between tenancies keeps a property looking cared for before the next move-in.
If you manage several properties in or around Radwell, several properties can go on one quote. Just tell us the addresses and what each one needs.
External mastic in Radwell, done properly
Ground-floor and low-level joints are straightforward to reach. Where joints are higher up, tell us about the building when you get in touch and we’ll confirm what’s needed to reach them safely. If you’re dealing with failed sealant between panels on a façade and brick movement joints where the sealant has split, we can put it right, on render & cladding joints, brickwork movement joints and façade panels alike.
In a village or hamlet like Radwell, older cottages and farm buildings often stand in the open, so walls and rooflines take the full force of wind and rain. Gutter joints and wall joints there need a sealant that can flex and stay put.
The work is covered for a year after we finish. If anything is not right with it, call 0345 464 0079 or send us an email.
- Location
- Radwell (SG7)
- Region
- Hertfordshire
- Guarantee
- 12 months on all our work
- Quote
- Quoted before any work starts
- Call
- 0345 464 0079
- Updated
- 26 October 2026
Towns and villages near Radwell
More services for Radwell
Surface by surface
Joints between dissimilar materials
Wherever two materials meet, they move differently. We seal the joint with a flexible exterior sealant.
Cladding and façade panels
If the façade has a specified sealant, that is what we use or an approved alternative. Send us any details you have about the façade.
External mastic in Radwell: local notes
Historic houses like Hinxworth Place (about 2.4 miles north) are a reminder that the area around Radwell has older buildings as well as new. In older buildings, older brick and stone need a sealant that suits them, at the right joint depth. Compared with the north and west, the South East gets less rain, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
Managing a site like Norton St Nicholas CofE (VA) Primary School? Then its movement joints, gutters and trims need looking after like any other building’s. If you let a flat or house near Baldock station, split movement joints are easy to miss on a rental until damp shows inside.
Radwell is about 2 miles north of Letchworth, in Hertfordshire. Radwell gets the same service as everywhere we cover: old sealant removed completely, careful preparation and a 12-month guarantee. Across Hertfordshire, we cover 381 places, and Radwell is one of them. You can also see our page for London, roughly 35 miles from Radwell.
Work in SG7 is quoted and booked the same way as anywhere else. You’ll find streets such as Radwell Lane and The Limes, all of which we cover. We also cover Stotfold (1 mile west), Stotfold Common (2 miles north-west), Fairfield (2 miles west) and Astwick (2 miles north-west). Within a short drive, we also cover Stevenage (7 miles south), Welwyn Garden City (14 miles south), Harpenden (15 miles south-west), Hitchin (5 miles south-west), Hertford (15 miles south) and Ware (15 miles south-east).
Around Radwell
In Radwell, that means homes and buildings near The Knights Templar School, Norton School and The Chequers Public House and the streets around them. The closest station to Radwell is Baldock station, roughly 1.2 miles south-east. Nearby you’ll also find Bygrave House (2 miles east) and Fairfield Hospital (1.9 miles west). For a walk, there’s Arlesey Old Moat and Glebe Meadows.
What we can’t put right
Before booking, it’s worth knowing the limits too:
- Damp from another source, such as a leaking gutter or a bridged damp-proof course
- Cracks in the bricks or render themselves, away from the joints
- Adding movement joints to masonry that has none
If in doubt, call 0345 464 0079 or email us and we’ll say what we think before booking.
What we seal
- Façade panels
- Concrete & block
- Copings & trims
- Render & cladding joints
- Brickwork movement joints
- Joints between brick and frames
Common questions in Radwell
Do you work for landlords with property near Baldock station?
Yes, rental work is part of what we do. Just ring 0345 464 0079 or email us and tell us about the property, and we will send you a clear quote.
Is Radwell 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.
Is the work guaranteed?
Yes. All our work carries a one-year guarantee.
Can you reach joints on upper floors?
Each building is different. Tell us the height, the number of joints and what’s below them.
What’s an expansion joint in brickwork?
A movement joint is a planned break in the wall that absorbs expansion and shrinkage. It’s sealed with a flexible sealant, not mortar.
Should I point up the gap in my brickwork?
No. Cement or mortar cannot stretch, so the joint stops doing its job. If it has already been filled, we can usually cut it out and reseal it.
Where is Mr Mastic based?
We are based in Crawley, West Sussex, and we cover South East England, London and all of Scotland.
Will there be a smell?
Some sealants have a smell while they cure, which fades as it sets. Opening a window helps.
Can I do it myself?
Some sealant jobs are within reach of a careful DIYer, such as a straightforward joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
The difference is mostly in the preparation and the product. We take joints back to clean, dry surfaces, and the sealant is matched to the joint and its conditions, and the work is guaranteed for a year.
Quotes for external mastic in Radwell
Jobs vary more than people expect. What affects the quote:
- Mould in or behind the old joints
- The product the joint needs
- Whether the work is at height
- When we can work, for business premises
Every job is a little different, so we quote each one individually. The number of joints, how easy they are to reach and the sealant needed all make a difference.
What we need to know
What to tell us when you ask for a quote:
- Access, such as stairs, a lift or height
- Roughly how big the job is
- The type of property
- Any previous sealing or DIY work
To get a quote, ring 0345 464 0079 or email us and tell us where the job is and what the problem looks like. We will give you a clear quote before any work starts.
What we’re called out for in Radwell
Buildings move more than people expect. Clay bricks expand slightly over their life, concrete and block shrink, and everything moves with temperature and wet. The sealant in the movement joints takes that strain.
People generally contact us when they notice one of these:
- Sealant pulling away from one side of the joint
- Movement joints with cracked, split or missing sealant
- Movement joints filled with mortar instead of sealant
- Leaking joints around cladding and façade panels
In the older streets around Church of All Saints, an extension built onto an older house moves differently, and the joint between them takes the strain.
What your quote should include
- How the joint is cleaned and prepared
- What the cure time is
- Is VAT in the price?
- The length of the guarantee
How it works
When we get to you, we compare the joints with what we discussed. If we find something unexpected, we talk it through with you first. After that, the work takes a few hours for a handful of joints, longer for a whole elevation. In a small place like Radwell, access is normally the main thing to plan. If the job is outside, mention outbuildings, exposed walls and how to reach them.
- We inspect the joints and agree which need resealing and how they’ll be reached.
- The old mastic and anything lodged in the joint is removed.
- The joint faces are cleaned and primed where the sealant needs it.
- Backing rod goes in next, setting the depth and keeping the sealant off the back of the joint.
- A flexible exterior sealant is applied and tooled in a colour to suit the wall.
Getting ready for the visit
- Try not to wet indoor joints just before the visit
- Keep pets and children clear of the area while we work
- On commercial sites, let us know about site rules
Get a quote
We do not publish a price list, as no two jobs are quite the same. Instead, we give you a clear quote for your job. To arrange one, phone 0345 464 0079 or drop us an email.