Greater London · England
Sand Mastic in Brockley
Sand mastic for Brockley, by sealant specialists with 20+ years’ experience. Rated 4.9 on Google from 180+ five-star reviews.
- Crumbling sand mastic round a window
- Tired mastic found when preparing windows for paint
- Gaps where the frame meets the masonry
Sand mastic in Brockley
Silicone on a period window often looks wrong and is not always the right material. Sand mastic gives a finish that matches the age of the house, and we can replace one with the other. If you’re dealing with silicone on a period window that looks wrong and gaps where the frame meets the masonry, we can help, on period & listed homes, stone surrounds and sash and case windows alike.
From mansion-block windows to modern glazing in new flats, London has every kind of frame. The mastic around them dries out and cracks with age, which is when draughts and damp patches appear in homes in Brockley.
All our work comes with our 12-month guarantee, wherever you are in Greater London.
- Location
- Brockley (SE4, SE23, SE6)
- Wider area
- Greater London
- Cover
- One year on every job
- Price
- Quoted before any work starts
- Call
- 0345 464 0079
- Updated
- 26 October 2026
Why it’s worth doing now in Brockley
A silicone bead can be quicker, but on period stone or brick it often looks out of place. Sand mastic is the traditional material and finishes neatly against the masonry. In a flat in Brockley, failed sealant seldom stays inside your own four walls: water can reach the neighbours below, and gaps in fire-rated joints affect the whole building.
A failed joint rarely gets cheaper to fix by waiting. If you’re unsure, ring 0345 464 0079 or send us an email and we’ll give you an honest view and a quote.
Why choose Mr Mastic in Brockley
- We’re fully insured
- 180+ five-star Google reviews
- Neat joints and a tidy finish
- An ARBOMaster approved applicator
Take a look at our cost guide and what customers say.
Nearby places to Brockley
What else we do in Brockley
Brockley questions
Is parking a problem for a job in Brockley?
London parking needs a little planning, so let us know about permits, bays or a driveway when you book. The visit is then planned around what’s available.
Is Brockley in your area for sand mastic?
Yes, Brockley is within the area we cover. We work across 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’ll give you a clear price.
Where do you work from?
Our base is in Crawley, West Sussex, and we cover South East England, London and all of Scotland.
Is it possible to paint over sand mastic?
The usual advice is to leave sand mastic unpainted. If you are redecorating the window, ask us first and we’ll talk you through it.
Do you offer different sealant colours?
In most cases you can choose. We’ll explain which colours are available and agree one before work begins.
What exactly is sand mastic?
A traditional pointing material made from sand and a linseed-oil-based binder, used between timber frames and stone or brick.
Will there be a smell?
Some sealants have a smell while they cure, but it fades. Opening a window helps.
Do you have insurance?
Yes. We are fully insured.
What sealant work cannot fix
In fairness, some problems need a different trade:
- Decisions on consent for listed homes
- Sashes that need overhauling
- Damaged stone surrounds
If you’re not sure, just call 0345 464 0079 or drop us an email and we will give you a straight answer before booking.
What we seal
- Timber door frames
- Brick reveals
- Stone surrounds
- Sash and case windows
- Period & listed homes
- Tenement windows
Quotes for sand mastic in Brockley
Your quote is based on your job. We look at:
- Access and height
- Whether there’s mould to deal with
- How many areas need sealing
- The number and length of the joints
Rather than a set price list, we price the job in front of us: the amount of work, the old material and the access. You’ll know the price before we begin.
What to tell us for a quote
There’s no need for technical detail. Just tell us:
- Access, such as stairs, a lift or height
- The address or postcode of the job
- If it’s domestic, commercial or a hotel
- What’s wrong with the joints now
We quote each job on its own, so start by telling us what you need. Simply ring 0345 464 0079 or email us and describe the job, and photos are welcome.
Landlords, agents and businesses in Brockley
If you manage several properties in or around Brockley, jobs at different addresses can be quoted together. Just tell us the addresses and what each one needs.
Failed sealant is one of the commonest items on a check-out report, and it’s easy to sort out between tenants. We can quote for more than one property at once.
When to call us in Brockley
Decorating can disturb tired mastic. Many people find it crumbling when they prepare the windows.
Signs it’s time to call us include:
- Draughts and rain around sash boxes
- A silicone bead on a sash window that spoils the look
- Crumbling sand mastic round a window
- Open joints round the window box
Homes close to Church of St Hilda include some older properties, and the joint between an old wall and a newer frame is usually the first place rain gets in.
Comparing quotes
- Whether you can choose the colour
- Who does the work, and how experienced they are
- What insurance they hold
- Whether VAT is included
Brockley homes and the weather
Rainfall in the South East is lower than in much 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 Queen's House (about 2.4 miles north-east) nearby, there’s older building stock in the area around Brockley as well as newer homes. In older buildings, older frames set in brick or stone need a sealant that suits them, and sometimes that is traditional sand mastic.
If you let a flat or house near Crofton Park station, any sash windows need sound mastic to keep draughts and rain out. As a London address, Brockley can be tricky for parking: tell us about permits, visitor bays or off-street space when you book.
Brockley is about 1 mile south of New Cross, in Greater London. Our applicators cover sand mastic for householders, landlords and businesses in Brockley and the surrounding area. Across Greater London, we cover 764 places, and Brockley is one of them.
Work in SE4, SE23 and SE6 is quoted and booked the same way as anywhere else. Sand mastic is available to properties on Ivy Road, Nash Road and Lindal Road and the roads around them. Close by, we work in Crofton Park (1 mile south-east), Honor Oak (1 mile west), Ladywell (1 mile east), Forest Hill (1 mile south-west) and Nunhead (1 mile north-west). We also work in nearby towns such as London (4 miles north-west), City of Westminster (7 miles north-west), Marylebone (7 miles north-west), Kensington (8 miles north-west), St Pancras (6 miles north-west) and Shoreditch (5 miles north).
Around Brockley
Locally, jobs take us to homes and businesses close to Blythe Hill Tavern, Allenby Tutorial Trust and Blythe Hill Fields. There’s a railway station in Brockley itself: Crofton Park station. Other landmarks nearby include Horniman Museum and Gardens (1.4 miles south-west) and University Hospital Lewisham (0.7 miles east). For a walk, there’s One Tree Hill and Knight's Hill.
How the visit works
On the day, there’s very little for you to do. Show us the job and we will take it from there. The job generally takes a few hours for a single window, longer for several from start to finish. In a London area like Brockley, the main things to plan are parking and access: let us know about parking, the floor we will be working on and any lift or shared entrance.
- We start by checking each surround and agreeing the joints to renew.
- The loose and crumbling mastic is raked out and the joint cleaned.
- We pack any deep gaps so the mastic sits at the right depth.
- The mastic is mixed, pressed into the joint by hand and shaped.
- The mastic is finished to sit tidily against the stone or brick.
Getting ready for the visit
- Clear items away from the joints we’re working on
- Where the joints are inside, avoid wetting them before we arrive
- Let us know about stairs, lifts or work at height
How to get a quote
Quotes start with a quick conversation. Tell us what’s wrong, where it is and how much there is, and we’ll explain how we’d tackle it. When it suits you, call 0345 464 0079 or email us.
Related advice
DIY versus a professional finish
If you do try it yourself, take your time over the preparation: take out all the old sealant, make sure the joint is clean and dry, and give it the full cure time. If it doesn’t work out, we can still put it right.
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.