Hertfordshire · England
Codicote Bottom External Mastic
We cover Codicote Bottom 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.
- Brick movement joints where the sealant has split
- Hard, crazed mastic that has stopped moving
- Joints pointed up with cement by mistake
Codicote Bottom: your questions answered
Do you cover Codicote Bottom for external mastic?
Yes, Codicote Bottom is within the area we cover. Our work covers London and the South East. You can phone 0345 464 0079 or send us an email and let us know what needs doing, and we will send you a clear quote.
I let a flat near Welwyn North station. Can you help?
Yes, landlords and agents are among the people we work for. You can phone 0345 464 0079 or email us with the details for a clear quote.
When will the joints need doing again?
It varies with how exposed the wall is and how much the joint moves. Signs to watch for are cracking, hardening and gaps at the edges, and reseal at that point.
How long should I leave it?
Different products cure at different speeds, so please follow the time we give you when we finish.
How long does the job take?
Most jobs take a few hours for a handful of joints, longer for a whole elevation, including preparation and clearing up. Your quote will say how long we expect yours to take.
Should I point up the gap in my brickwork?
No. A mortar-filled joint cannot move, so the movement cracks the wall elsewhere. Use a flexible sealant with backing rod.
Do you hold any approvals?
Yes. We are approved under the ARBOMaster scheme, the approved applicator scheme for Arbo sealants.
Are you fully insured?
Yes. We’re fully insured, and we have been doing sealant work for more than 20 years.
How we handle external mastic in Codicote Bottom
Short cuts in external joints show up within a season or two. Overfilled joints, missing backing rod and sealant laid over old sealant rarely last long. We strip the joint back and start again. We work on brickwork movement joints, joints between brick and frames and copings & trims, and common reasons people get in touch are sealant that has lost its bond to the brick or render and gaps where render, brick and frames meet.
In a village or hamlet like Codicote Bottom, 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.
All of our work is guaranteed for twelve months, in Codicote Bottom and everywhere else we cover.
- Place
- Codicote Bottom (SG4)
- Region
- Hertfordshire
- Guarantee
- 12 months on all our work
- Price
- A clear price before work begins
- Call
- 0345 464 0079
- Last updated
- 26 October 2026
Can I do it myself?
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.
Not every job suits DIY: high-level joints, fire-rated gaps, external movement joints and big jobs need the right product, the right access and the right method.
What affects the quote in Codicote Bottom
Jobs vary more than people expect. What affects the quote:
- How easy the joints are to reach
- The type of sealant required
- Mould in or behind the old joints
- Any working-time requirements on site
Leaving a failed joint usually makes the job bigger, not smaller, because water and mould keep working on it. If you’re not sure whether it needs doing, call 0345 464 0079 or email us for an honest opinion and a quote.
What we need to know
You do not need to know the technical terms. It helps if you can tell us:
- How we’d reach the joints
- What the problem is, such as mould, gaps, leaks or cracking
- Photos by email, if that’s easy
- Roughly how big the job is
For a quote, ring 0345 464 0079 or drop us an email with the location and a short description of the problem. We’ll give you a clear quote before any work starts.
Codicote Bottom buildings and the weather
The South East is one of the drier parts of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind. Historic houses like Shaw's Corner (about 1.3 miles south-west) are a reminder that the area around Codicote Bottom 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.
For landlords with property near Welwyn North station, outside joints that have cracked can let damp into a rental, so check them between lets. Schools such as Codicote Church of England Primary School are buildings too, and movement joints, cladding joints and gutters on larger buildings need the same care as a house’s.
Codicote Bottom is about 4 miles north-west of Welwyn Garden City, in Hertfordshire. From the centre of Codicote Bottom to the outskirts, external mastic is available for homes and businesses alike. Codicote Bottom is one of 381 towns and villages in Hertfordshire we cover. You can also see our page for London, about 25 miles away.
Work in SG4 is quoted and booked the same way as anywhere else. External mastic is available to properties on Heath Hill and Kimpton Road and the roads around them. Neighbouring places we cover for external mastic include Codicote (1 mile east), Ayot St Lawrence (1 mile south-west), Driver's End (1 mile north-east), Nup End Green (2 miles north-east) and Ayot St Peter (2 miles south). Larger places within reach include Watford (14 miles south-west), Hemel Hempstead (11 miles south-west), Stevenage (5 miles north-east), St Albans (7 miles south-west), Welwyn Garden City (4 miles south-east) and Harpenden (5 miles south-west).
Around Codicote Bottom
In Codicote Bottom, that means homes and buildings near Danesbury Park, The Goat Public House and Monk's Walk School, among other places. The nearest railway station is Welwyn North station, roughly 2.9 miles south-east of the centre. A little further out are Howard Centre (3.7 miles south-east) and Datchworth Museum (3.8 miles east). Green spaces nearby include Stocking Springs Wood.
Honest limits
Before booking, it’s worth knowing the limits too:
- Damp from another source, such as a leaking gutter or a bridged damp-proof course
- Subsidence or other structural problems
- Cracked brickwork or render that needs a builder or plasterer
If you’re not sure, just phone 0345 464 0079 or send us an email and we will give you a straight answer.
Surfaces we seal
- Brickwork movement joints
- Render & cladding joints
- Joints between brick and frames
- Copings & trims
- Concrete & block
- Façade panels
Looking after it afterwards
No joint lasts for ever, but care makes a real difference. A few tips:
- Tell anyone working on the walls about the movement joints
- Clear growth from the base of walls and joints
- Leave the joints unpainted unless we have said otherwise
- Deal with leaking gutters that soak the joints below
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.
Small splits are the time to act. At that stage it’s a simple cut out and reseal.
For landlords and businesses
If you manage several properties in or around Codicote Bottom, several properties can go on one quote. Send us the addresses and the work at each.
We also work for businesses, from offices to washrooms and kitchens. On commercial sites, working times can be discussed when we quote.
Signs you need external mastic in Codicote Bottom
Joints sealed without backing rod, or far too deep, rarely last. If the sealant sticks to the back as well as the sides, it cannot stretch and rips as the joint opens.
Any of these means the joints need attention:
- Rigid filler in a joint that should flex
- Joints where the bead has come unstuck
- Panel joints letting water in
- Rain getting behind render or cladding at a joint
Homes close to Parish Church of St Giles include some older properties, and an extension built onto an older house moves differently, and the joint between them takes the strain.
What your quote should include
- Is VAT in the price?
- What happens if they find a problem under the old sealant
- What insurance they hold
- How the surfaces are prepared before sealing
How the visit works
At the end, we look at the finished work together and tell you how long to leave it. The visit itself normally takes a few hours for a handful of joints, longer for a whole elevation, depending on how much there is to do. Somewhere as small as Codicote Bottom, access is often the only tricky part. For outside work, also let us know about exposed walls and any outbuildings involved.
- First, the joints are inspected and the access agreed.
- 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.
- Backing rod sized to the joint goes in to set the depth.
- The exterior sealant is applied, tooled and checked along its length.
Getting ready for the visit
- Mention any leaks or damp you’ve noticed
- Keep pets and children clear of the area while we work
- Let us know about stairs, lifts or work at height
Getting a quote
The more we know about the job, the more useful the quote. Tell us where the job is, what’s wrong and how much there is, and email pictures if that’s easy.