Greater London · England
External & façade joints in Poverest, Greater London
External mastic for Poverest, by sealant specialists with 20+ years’ experience. Rated 4.9 on Google from 180+ five-star reviews.
- Joints pointed up with cement by mistake
- Movement joints with cracked, split or missing sealant
- Failed seals between different materials
External mastic in Poverest
As ARBOMaster approved applicators, we choose exterior sealants to suit the joint and the surfaces. Porous or awkward surfaces are primed where the sealant needs it. We’re often asked to deal with hard, crazed mastic that has stopped moving and weeds or debris growing in open joints, on concrete & block, joints between brick and frames and brickwork movement joints.
In London terraces and converted houses, gutters and walls are often shared with the house next door, so one failed joint can cause damp for more than one household. For a flat in Poverest, check the lease for who looks after the outside.
We guarantee the work for a year. If something is not right with it in that time, tell us and we’ll put it right.
- Location
- Poverest (BR5, BR6, BR7)
- Region
- Greater London
- Guarantee
- One year on every job
- Price
- A clear price before work begins
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
Quotes for external mastic in Poverest
Your quote is based on your job. We take into account:
- How much old sealant there is and how hard it is to remove
- Any working-time requirements on site
- The product the joint needs
- Whether there’s mould to deal with
Some things make a job bigger or smaller: how much old sealant there is and how stubborn it is, any mould to treat, and whether the work is at height. We take all of that into account in your quote.
What we need to know
When you call or email, it’s useful to know:
- Whether it has been sealed before
- The rough size of the job
- If it’s domestic, commercial or a hotel
- What’s wrong with the joints now
We don’t publish a price list. Instead, we give you a clear quote for your job. To get started, call 0345 464 0079 or drop us an email.
What we do, step by step
We work through the job in order: protect, prepare, seal, tidy. Typically it takes a few hours for a handful of joints, longer for a whole elevation and we leave things clean and tidy. Parking in much of London is by permit or pay-and-display, so it helps to know what’s near you in Poverest. A visitor permit or a nearby bay makes the visit run more smoothly.
- 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.
How to prepare
- Tell us about access, such as stairs, a lift or high-level joints
- Let us know about parking restrictions
- Tell us about any previous sealing or DIY attempts
How to get a quote
Want a quote for external mastic? Please phone 0345 464 0079 or send us an email with a few details. You will know what we plan to do, and what it will cost, before any work begins.
Advice
Walls and rooflines in Poverest
With historic houses such as Bromley Palace (about 3.5 miles west) nearby, there’s older building stock in the area around Poverest 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. London terraces and converted houses often share gutters, downpipes and walls, so check who is responsible for the outside before booking.
If you live in an older home near St Andrew's, old and new materials meet at the roofline and walls, which is where sealant earns its keep. Managing a site like Poverest Primary School? Then larger buildings have long runs of movement joint that eventually need resealing.
Poverest is about 1 mile north of Orpington, in Greater London. Homes, rented property, offices and hotels in Poverest can book us for external mastic, old or new, large or small. Every job comes with our one-year guarantee. Poverest is one of 764 places in Greater London we cover. We also work in London, around 11 miles away.
Our applicators cover all of the BR5, BR6 and BR7 postcode area for external mastic and the streets around it. We cover properties on Kent Road, Ascot Road and Sheen Road and the roads around them. You’ll find Poverest on the A224, so it’s easy for us to get to. Close by, we work in St Mary Cray (1 mile north-east), Orpington (1 mile south), St Paul's Cray (1 mile north), Derry Downs (1 mile south-east) and Kevington (2 miles east). Within a short drive, we also cover London (11 miles north-west), City of Westminster (14 miles north-west), Marylebone (14 miles north-west), Kensington (15 miles north-west), St Pancras (13 miles north-west) and Shoreditch (12 miles north-west).
Landmarks near Poverest
In Poverest, that means homes and buildings near Walsingham School, Harris Academy Orpington and The Royal Albert pub and the streets around them. There’s a railway station in Poverest itself: St Mary Cray station. A little further out are Orpington Hospital (1.9 miles south) and Lullingstone Castle (4.7 miles south-east). Green spaces nearby include Summer Hill and The Warren.
Surface by surface
Render joints
Render is weaker at the surface than brick, so a low-modulus sealant is kinder to the joint edges. Priming is done where the sealant calls for it.
Joints between dissimilar materials
Joints where frames, sills or panels meet the wall are common leak points. The old joint is removed and a sealant that bonds to both sides goes in.
Places near Poverest
Other services in Poverest
DIY sealant or a professional job?
The biggest DIY mistake is sealing over old sealant. Silicone does not stick to old silicone, so it lifts and traps water and mould underneath. Everything old must be removed first.
Overfilling a joint is a classic DIY mistake. A thick, smeared bead looks untidy and doesn’t move well, and the joint depth matters as much as the finish.
Signs you need external mastic in Poverest
Using the wrong sealant is another common reason. A stiff, general-purpose sealant cannot cope with a joint that moves a lot, so it pulls away from the edges.
Common reasons people contact us include:
- Gaps where render, brick and frames meet
- Joints where the bead has come unstuck
- Hard, crazed mastic that has stopped moving
- Failed sealant between panels on a façade
If you let a flat or house near St Mary Cray station, failed wall and movement joints let damp in, so they’re worth checking between tenancies.
Before booking anyone
- What insurance they hold
- How hidden problems are handled
- The length of the guarantee
- Who turns up on the day
How to look after the new joints
So the new joints stay in good condition:
- Tell anyone working on the walls about the movement joints
- Act on the first splits you see
- Fix overflowing gutters above sealed joints
- Make sure movement joints are not pointed over
Only paint over the joint if we have confirmed the sealant can take paint. Paint can crack on a flexible joint.
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.
Your questions about external mastic in Poverest
Can parking be tricky for a visit in Poverest?
Parking in Poverest, as in most of London, takes a little planning: a visitor permit or a bay close to the door helps a lot.
Can you do external mastic in Poverest?
Yes, Poverest is within the area we cover. We work across London and the South East. Just call 0345 464 0079 or send us an email with a few details of the job, and we’ll give you a clear price.
Will it make a mess?
We keep the work tidy. We protect what’s around the joints.
Can you seal joints between render and window frames?
Yes. The old joint is removed, both surfaces cleaned and primed where needed, and a flexible sealant applied. We pick a colour that works with both materials.
How much does external mastic cost in Poverest?
The cost depends on the size of the job, access and how much old sealant has to come out. Ask us for a quote.
Is it OK to seal over old sealant?
No. New silicone won’t bond to old silicone, and anything trapped underneath, including mould and water, stays there. It all has to come out first.
Will the old sealant be removed?
Yes, always, and completely. New silicone doesn’t stick to old silicone, so the joint is cleaned back first.
Will there be a smell?
It depends on the product. Some smell for a while, some hardly at all, and any smell fades as they cure.
What sealant work cannot fix
Some problems need a builder, plumber or other trade rather than us:
- Cracked brickwork or render that needs a builder or plasterer
- Failed render or damaged cladding panels
- Structural movement, which needs a surveyor or engineer
Not sure which it is? You can call 0345 464 0079 or email us and we’ll tell you honestly before booking.
Where we work in Poverest
- Concrete & block
- Render & cladding joints
- Joints between brick and frames
- Façade panels
- Copings & trims
- Brickwork movement joints