Hertfordshire · England
External & façade joints in Pin Green, Hertfordshire
External mastic for Pin Green, by sealant specialists with 20+ years’ experience. 180+ five-star Google reviews and a 4.9 rating.
- Panel joints letting water in
- Moss and dirt in joints with no sealant left
- Failed seals between different materials
External mastic in Pin Green
Joints in render and cladding are easy to overlook until a damp patch appears. We inspect them, agree which need doing and reseal with a weatherproof, flexible sealant in a matching colour. If you have failed seals between different materials and rain getting behind render or cladding at a joint, we can put it right, whatever the surface.
Outbuildings, garages and conservatories around homes in places like Pin Green add more joints to look after. Leaks generally start at a gutter end, a garage door frame or where an extension meets the house.
All our work comes with our 12-month guarantee, wherever you are in Hertfordshire.
- Location
- Pin Green (SG1, SG2)
- Wider area
- Hertfordshire
- Cover
- One year on every job
- Quote
- A clear price before work begins
- Phone
- 0345 464 0079
- Updated
- 26 October 2026
When it is not the sealant
Some problems need a builder, plumber or other trade rather than us:
- Subsidence or other structural problems
- Failed render or damaged cladding panels
- Damp from another source, such as a leaking gutter or a bridged damp-proof course
If in doubt, call 0345 464 0079 or email us and we’ll say what we think before you book.
Joints and surfaces we work on
- Brickwork movement joints
- Concrete & block
- Joints between brick and frames
- Render & cladding joints
- Façade panels
- Copings & trims
Aftercare tips
Joint life depends on how it’s used and looked after. Here’s what we suggest:
- Keep high-pressure jets off the joints
- Walk round the building once a year and look at the joints
- Keep soil, plants and ivy away from the joints
- Have failed joints looked at early
Look over the joints once a year, ideally after winter. Splits, gaps at the edges or plants in the joint are early warning signs.
An open movement joint lets rain into the wall every time it pours. Over time it can mean damp inside, stained render or frost-damaged brick which cost more to put right than the joint.
Can I do it myself?
A careful DIYer can reseal a simple joint, 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.
Not every job suits DIY: high-level joints, fire-rated gaps, external movement joints and big jobs call for the right materials, safe access and experience.
How the visit works
We keep the work tidy and contained to the joints we are treating, so you can carry on as normal. Expect the work to take anything from a few hours to several days, depending on the building, and we explain the cure time before we leave. For a job in Pin Green, we agree the time, the access and parking before the day. If the work is outside, the weather plays a part, as sealant needs a dry surface.
- First, the joints are inspected and the access agreed.
- We cut out the old mastic and rake out anything in the joint.
- Joint faces are cleaned back and primed if the sealant needs 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
- Plan for the work area to be out of bounds to pets and children
- Tell us about access, such as stairs, a lift or high-level joints
- For business premises, tell us about site rules or sign-in
Ask for a quote
There’s no standard price list, because every job is different. Instead, your job gets its own clear quote. To get started, call 0345 464 0079 or send us an email.
Related advice
What affects the cost of external mastic
The quote reflects the job in front of us. We look at:
- How much there is to do
- The old material and how stubborn it is
- Which sealant suits the joint
- Any working-time requirements on site
What you pay reflects the work, not guesswork. That’s why we ask a few questions first.
What we need to know
Before you ask for a quote, have a think about:
- What’s wrong with the joints now
- Pictures of the joints, sent by email
- If it’s domestic, commercial or a hotel
- Any access issues, like height or stairs
Need a quote? Please phone 0345 464 0079 or email us with a few details. You will know what we plan to do, and what it will cost, before any work begins.
Common problems we fix in Pin Green
Poor preparation causes many early failures: dusty or wet faces, no primer where one was needed, or old sealant left in. The sealant never bonds properly.
Look out for any of the following:
- Gaps where render, brick and frames meet
- Joints with sealant missing in places
- Damp patches traced to an open external joint
- Weeds or debris growing in open joints
Letting a property close to Stevenage station? Then split movement joints are easy to miss on a rental until damp shows inside.
Comparing quotes
- Which sealant they’ll use, and why
- Whether VAT is included
- What insurance they hold
- Which colour the sealant will be
Common questions in Pin Green
Should the sealant in an older Pin Green home be renewed?
Normally, yes, if it’s cracked, shrunk, mouldy or coming away. The key is cutting all the old sealant out, as new sealant won’t bond to it.
Is Pin Green within the area you cover?
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.
Which products do you use?
The product depends on the job: sanitary silicone where it gets wet, and sealants suited to movement or weather elsewhere. We use products from Arbo and Everbuild.
Do you seal joints where cladding meets other materials?
Yes. Where different materials meet is one of the most common joints we seal. We use a flexible sealant suited to both surfaces, primed where needed.
What is backing rod for?
Backing rod controls the sealant depth and keeps it off the back of the joint. Then the sealant bonds to two faces and can move.
Do you hold any approvals?
Yes. ARBOMaster is the approved applicator scheme for Arbo sealants, and we are part of it.
How often do external joints need resealing?
That varies with the weather the wall faces, how much it moves and the sealant used. Treat it as a maintenance item and look at it yearly.
What information do you need?
Let us know what needs doing and where, plus pictures if you have them. We’ll ask anything else we need to know.
Nearby places to Pin Green
Other services in Pin Green
What external mastic looks like in Pin Green
Stevenage, which Pin Green is part of, is one of England’s post-war new towns. Many homes date from the post-war decades and were built in phases, so neighbouring houses often have rooflines and wall joints of the same age, wearing out at the same time. Compared with the north and west, the South East gets less rain, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
For an older house near a landmark such as Church of Saint Nicholas, the joints between older walls, newer extensions and the roofline need a sealant that can move. Managing a site like Trotts Hill Primary and Nursery School? Then its movement joints, gutters and trims need looking after like any other building’s.
Pin Green is about 1 mile north-west of Stevenage, in Hertfordshire. Pin Green 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 Pin Green is one of them. You can also see our page for London, roughly 29 miles from Pin Green.
We cover every part of SG1 and SG2 for external mastic. Whether your property is on Lines Road, Hawkes Lane and Aldock Road or a nearby road, our applicators can take on the job. We also cover the places around Pin Green: Stevenage (1 mile south-east), Bedwell (1 mile south), Rooks Nest (1 mile north), St Nicholas (1 mile north-east) and Chells (1 mile east). Larger places within reach include St Albans (13 miles south-west), Bishop's Stortford (15 miles east), Welwyn Garden City (8 miles south), Harpenden (10 miles south-west), Hitchin (4 miles north-west) and Hoddesdon (13 miles south-east).
Local landmarks in Pin Green
In Pin Green, that means homes and buildings near The Barclay School, The Standing Order pub and The John Henry Newman School, among other places. The closest station to Pin Green is Stevenage station, roughly 1.1 miles south-west of the centre. Well-known places in the area include Wymondley Castle (2.7 miles north-west) and Lister Hospital (1.2 miles north-west). Open spaces near Pin Green include Pryor's Wood.
How the job changes by surface
Brickwork movement joints
Brick movement joints are often mistaken for a missing mortar line. If that is happened, we rake it out and reseal it properly where it can be done safely.
Joints between dissimilar materials
Each side of the joint may need its own preparation. Both surfaces are cleaned and primed as the product requires.