Hertfordshire · England
External Mastic in Park Street
Sealing brickwork movement joints, render, cladding and façade joints for Park Street, backed by a 12-month guarantee. Call for a quick quote.
- Panel joints letting water in
- Brick movement joints where the sealant has split
- Sealant pulling away from one side of the joint
About our external mastic in Park Street
We cut out failed sealant, set the joint depth with closed-cell backing rod and reseal with a low-modulus exterior sealant. The colour is chosen to suit the brick or render. We work on joints between brick and frames, brickwork movement joints and concrete & block, and common reasons people get in touch are old sealant gone brittle and cracked and plants rooting in failed movement joints.
Older homes in small places like Park Street may be stone, brick or timber-framed, often with later extensions. Where one material meets another is where water normally gets in, and they need the right sealant at the right depth.
A one-year guarantee comes with the work, just as it does everywhere we cover.
- Place
- Park Street (AL2)
- Wider area
- Hertfordshire
- Cover
- One year on every job
- Quotes
- A clear quote up front
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
Landlord and commercial work in Park Street
Housing providers, facilities teams and property managers book us too. We can quote a run of properties together.
A neglected joint can let water reach the structure, which is a bigger problem in a rented property. Resealing at the right time is simple maintenance.
Why deal with it now?
Water gets in through a failed movement joint. Dealing with it early keeps the repair to the joint, rather than the wall around it. Older cottages and farmhouses around Park Street can have timber floors and frames, and water through a failed joint can rot timber if it’s left.
A failed joint rarely gets cheaper to fix by waiting, as water and mould keep getting in. If you’re unsure, phone 0345 464 0079 or email us and we’ll give you an honest view and a quote.
Why Park Street clients choose us
- A 12-month guarantee on all work
- Fully insured
- Homes, businesses and hotels
- Rated 4.9 stars on Google
Take a look at our cost guide and what customers say.
Common problems we fix in Park Street
UV, rain and frost all age exterior sealant. In time it goes hard, crazes on the surface and stops stretching, so the joint eventually tears or comes away from one side.
Look out for any of the following:
- Plants rooting in failed movement joints
- Panel joints letting water in
- Joints where the bead has come unstuck
- Brick movement joints where the sealant has split
Managing a site like Park Street Church of England Voluntary Aided Primary School? Then movement joints, cladding joints and gutters on larger buildings need the same care as a house’s.
Comparing quotes
- The length of the guarantee
- Is VAT in the price?
- Is the old sealant removed completely?
- When the joint can take water or movement
Your questions about external mastic in Park Street
Will you come out to Park Street?
Yes, Park Street is covered. Our work covers London and the South East, and smaller places are part of that. The journey is planned ahead, so it helps to know about access.
Can you do external mastic in Park Street?
Yes, Park Street is within the area we cover. We work across London and the South East. You can call 0345 464 0079 or drop us an email and let us know what needs doing.
Is there any odour?
Sometimes, a little. It fades as the sealant cures, and ventilation helps.
Can you work on commercial sites?
Yes. We can plan bigger jobs in stages to suit the site.
Are you an approved applicator?
Yes. ARBOMaster is the approved applicator scheme for Arbo sealants, and we’re part of it.
When is the sealant fully cured?
Many sealants skin over quickly but take longer to cure fully. We’ll tell you how long to leave the joint before we leave.
Are you insured?
Yes. We are fully insured.
Can landlords and businesses book you?
Yes. Domestic, commercial and hotel work are all part of what we do.
How it works
The work is kept neat and contained to the area we’re working on. Expect the work to take a few hours for a handful of joints, longer for a whole elevation, and we tell you how long to leave it before we go. For a village or hamlet like Park Street, the journey is planned in advance: tell us about narrow lanes, gates, long drives and where we can park. We bring what the job needs, so it can be finished in one trip where possible.
- We inspect the joints and agree which need resealing and how they’ll be reached.
- Old sealant and any debris are cut and raked out.
- Both sides are cleaned back to sound material and primed if needed.
- 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
- Try not to wet indoor joints just before the visit
- Tell us about access, such as stairs, a lift or high-level joints
- Mention if the joints have been sealed before
Get a quote
If you’re in Park Street and need external mastic, call 0345 464 0079 or drop us an email. A short description of the job and where it is helps us quote, and you’ll get a clear quote before we start.
Read more
What external mastic looks like in Park Street
London and the South East are among the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast. With historic houses such as High Elms Manor (about 2.7 miles south-west) nearby, there’s older building stock in the area around Park Street as well as newer homes. Where a home is older, older walls and rooflines need a sealant that moves with them and suits the material.
For landlords with property near Park Street station, failed wall and movement joints let damp in, so they’re worth checking between tenancies. Homes close to Church of the Holy Trinity include some older properties, and an extension built onto an older house moves differently, and the joint between them takes the strain.
Park Street is about 2 miles south of St Albans, in Hertfordshire. From the centre of Park Street to the outskirts, we cover external mastic for every kind of property. Across Hertfordshire, we cover 381 places, and Park Street is one of them. We also work in London, around 19 miles away.
All of AL2 is covered for external mastic. If you need external mastic at a property on Park Street, Burydell Lane and Oliver Close or a nearby road, we can help. Close by, we work in Frogmore (1 mile south-east), How Wood (1 mile south-west), Chiswell Green (1 mile west), Sopwell (1 mile north) and Colney Street (1 mile south-east). Larger places within reach include Watford (5 miles south-west), Hemel Hempstead (6 miles west), Stevenage (14 miles north-east), Welwyn Garden City (8 miles north-east), Harpenden (6 miles north) and Hoddesdon (14 miles east).
Landmarks near Park Street
Around Park Street, our work takes us to homes and buildings near The Falcon pub, Marlborough Science Academy and Verulamium Park, among other places. Park Street has its own railway station: Park Street station. A little further out are Hypocaust Museum (1.9 miles north) and Napsbury Hospital (1.3 miles east). The countryside around Park Street includes Verulamium Lake and Broad Colney Lakes.
How the job changes by surface
Brickwork movement joints
Vertical joints in long brick walls let the brickwork expand without cracking. They’re resealed over backing rod with a low-modulus sealant.
Joints between dissimilar materials
Wherever two materials meet, they move differently. We seal the joint with a flexible exterior sealant so neither cracks the other.
Should I try it myself first?
The biggest DIY mistake is sealing over old sealant. Silicone doesn’t stick to old silicone, so it lifts and traps water and mould underneath. All the old material has to come out first.
Overfilling a joint is a classic DIY mistake. A heavy bead looks messy and copes badly with movement, and getting the depth right matters as much as the look.
Keeping the joints in good condition
How long the joints last depends on use and care. We suggest:
- Have failed joints looked at early
- Tell anyone working on the walls about the movement joints
- Clear growth from the base of walls and joints
- Walk round the building once a year and look at the joints
Do not let soil, plants or ivy build up against the new joints. Anything that holds water against the joint wears it out sooner.
If you can see gaps, plants or bare sections in a joint, have it checked. Earlier resealing means a smaller job and a better result.