Greater London · England
Crook Log External Mastic
External mastic in Crook Log from a team with over 20 years’ experience. Rated 4.9 on Google from 180+ five-star reviews.
- Movement joints with cracked, split or missing sealant
- Rigid filler in a joint that should flex
- Sealant that has lost its bond to the brick or render
Keeping the joints in good condition
After the cure time, these simple habits help:
- Act on the first splits you see
- Look over the joints every year, ideally after winter
- Show decorators and builders where the movement joints are
- Make sure movement joints aren’t pointed over
Don’t let soil, plants or ivy build up against the new joints. Damp material against the sealant shortens its life.
Small splits are the time to act. Then it’s a straightforward cut-out and reseal before water has had years to get in.
External mastic for homes and businesses in Crook Log
Joints between dissimilar materials, like brick against render or concrete against a steel frame, see movement from both sides. A flexible exterior sealant takes up that movement where a rigid filler would soon crack. If you have movement joints with cracked, split or missing sealant and rain getting behind render or cladding at a joint, we can put it right, whatever the surface.
London’s terraces and conversions often share walls, gutters and downpipes with their neighbours, so a leaking gutter joint or failed wall joint can affect more than one home. For a flat in Crook Log, check the lease for who looks after the outside.
All of our work is guaranteed for twelve months, in Crook Log and everywhere else we cover.
- Place
- Crook Log (DA7, DA6, DA16)
- Region
- Greater London
- Cover
- 12 months on all our work
- Price
- Quoted before any work starts
- Call
- 0345 464 0079
- Last updated
- 26 October 2026
Should I try it myself first?
Overfilling a joint is a classic DIY mistake. A heavy bead looks messy and copes badly with movement, and the joint depth matters as much as the finish.
A DIY attempt does not rule out a professional job. We remove it and do the joint properly.
What the job involves on each surface
Joints between dissimilar materials
Different materials may need different primers. Both surfaces are cleaned and primed as the product requires.
Copings and trims
A failed coping joint lets water into the top of the wall. Resealing them is a small job that protects a lot.
What happens if it’s left?
Water gets in through a failed movement joint and can run behind render or cladding. Dealing with it early keeps the repair to the joint, instead of the wall and finishes around it. In a London flat, a failed joint rarely stays your problem alone: water from a shower or window joint can reach the flat below, and gaps in fire-stopping matter to everyone in the building.
Leaving a failed joint generally makes the job bigger, not smaller. If you are not sure whether it needs doing, call 0345 464 0079 or email us for an honest opinion and a quote.
Why Crook Log customers choose us
- White, clear, grey or another colour, product permitting
- ARBOMaster approved applicator
- Fully insured
- Domestic, commercial and hotel work
See what affects the cost and what customers say.
Work for landlords, hotels and businesses
If you manage several properties in or around Crook Log, several properties can be quoted together. Send us the addresses and the work at each, and photos by email help.
A neglected joint can let water reach the structure, which is a bigger problem in a rented property. Keeping joints in good order is simple maintenance that we can handle for you.
Places near Crook Log
What else we do in Crook Log
Do you need external mastic in Crook Log?
Poor preparation causes many early failures: dusty or wet faces, no primer where one was needed, or old sealant left in. The new sealant then lets go long before it should.
People generally contact us when they notice something like this:
- Sealant pulling away from one side of the joint
- Leaking joints around cladding and façade panels
- Joints with sealant missing in places
- Rain getting behind render or cladding at a joint
Rented homes near Bexleyheath station change hands often, and failed wall and movement joints let damp in, so they’re worth checking between tenancies.
What your quote should include
- Whether you can choose the colour
- What the cure time is
- Whether all the old sealant comes out first
- Who turns up on the day
How the visit works
A visit follows a simple pattern: we check the joints, protect the area around them, carry out the job and tidy away. It normally takes a few hours for a handful of joints, longer for a whole elevation. In Crook Log, flats, stairs and shared entrances are part of the routine. Mention any building rules, key holders or managing agents when you book.
- Each joint is checked and the colour of the new sealant agreed.
- Failed sealant is removed back to clean, sound faces.
- Closed-cell backing rod is pushed in so the sealant bonds to two sides only.
- We prime the faces where required.
- We gun in low-modulus sealant and tool it neatly.
How to prepare
- Where the joints are inside, avoid wetting them before we arrive
- Let us know about parking restrictions
- Tell us about any previous sealing or DIY attempts
Get a quote
Asking for a quote is easy: tell us what needs doing and where. A few photos by email make the job easier to understand.
Advice
Crook Log: your questions answered
Do you cover Crook Log for external mastic?
Yes, Crook Log is within the area we cover. Our work covers London and the South East. Just phone 0345 464 0079 or email us with a few details of the job, and we’ll send you a clear quote.
Is parking a problem for a job in Crook Log?
In much of London, parking needs planning: a visitor permit or a nearby bay makes the day run more smoothly, so mention what’s available when you book.
Why is there a gap in my brick wall?
A vertical gap in a long brick wall is generally a movement joint. It lets the bricks expand without cracking.
Do you seal joints where cladding meets other materials?
Yes. Different materials move at different rates, so the joint between them must be flexible. We choose one that suits both surfaces.
Do you work for landlords and businesses?
Yes, regularly. We can quote for several properties at once, and between tenancies is a good time for the work.
Do I need to be at home?
We need access to the joints, so we’ll agree that with you when we book. For inside work, that normally means someone being in.
Can you quote for more than one area?
Yes. Just list everything you need and we will quote it together.
Where are you based?
We work from Crawley. We cover Crook Log and the rest of Greater London, along with the rest of our area.
Walls and rooflines in Crook Log
Rainfall in the South East is lower than in much of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day. London terraces and converted houses often share gutters, downpipes and walls, so check who is responsible for the outside before booking.
In the older streets around Trinity Baptist Church, an extension built onto an older house moves differently, and the joint between them takes the strain. Crook Log is in London, so parking needs planning: let us know about parking bays, permits or a driveway.
Crook Log is about 3 miles south-east of Plumstead, in Greater London. If you need external mastic in Crook Log, please ring 0345 464 0079 or email us for a quick quote. We’re based in Crawley and cover Greater London, Crook Log included. Crook Log is one of 764 places in Greater London where we work. Our London page covers work nearby.
Our applicators cover all of DA7, DA6 and DA16 for external mastic and the streets around it. We cover properties on Bean Road, Lion Road and Alers Road. Other places close to Crook Log include Upton (1 mile east), Bexleyheath (1 mile east), Welling (1 mile west), Blendon (1 mile south) and Bexley (1 mile south). Larger places within reach include London (10 miles west), City of Westminster (13 miles west), Marylebone (12 miles west), Kensington (14 miles west), St Pancras (11 miles north-west) and Shoreditch (10 miles north-west).
Local landmarks in Crook Log
In Crook Log, that means homes and buildings near Danson Park, St Columba's Catholic Boys' School and The Crook Log Public House. Crook Log has its own railway station: Bexleyheath station. Other landmarks nearby include Bexley Museum (1.7 miles south-east) and Broadway Shopping Centre (0.9 miles east). For a walk, there’s Summer Hill and Wansunt Pit.