Greater London · England
Sand mastic for sash & case windows in Bexleyheath, Greater London
Window and door surrounds in Bexleyheath need attention? We cut out the old, prepare the joints and apply the right sealant.
- Gaps between timber frames and stone or brick
- Patchy fillers round a sash window
- Weathered mastic on the most exposed windows
Sand mastic in Bexleyheath
Across Bexleyheath, we renew sand mastic around sash and case windows. Each joint is raked out, prepared and pointed by hand, finished to suit the masonry. We are often asked to deal with mastic round period door frames that has failed and window mastic to renew ahead of painting, on period & listed homes, timber door frames and brick reveals.
London homes have every kind of window, from timber sashes in period terraces to aluminium and uPVC in newer blocks. Over the years, the sealant around them shrinks, cracks and pulls away, which is when draughts and damp patches appear in homes in Bexleyheath.
We guarantee the work for a year. If there’s a problem with our work within the year, let us know and we will sort it.
- Place
- Bexleyheath (DA7, DA6, DA16)
- Region
- Greater London
- Guarantee
- A year, on every job
- Price
- A clear quote up front
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
Keeping the joints in good condition
How long the joints last depends on use and care. Here’s what we suggest:
- Keep modern sealant off the mastic
- Check with your local planning authority if your home is listed
- Make sure water runs off the sill
- Plan mastic work ahead of painting
When preparing windows for paint, take care around the mastic. Hard scraping can loosen it.
An open joint round the box lets weather through. Left, the gap tends to get bigger as more mastic falls out.
What affects the quote in Bexleyheath
Call for a quick quote. The main things that affect it are:
- Any mould that needs treating
- How many areas need sealing
- When we can work, for business premises
- The size of the job
Every job is a little different, so each one gets its own quote. Size, access and the product the joint needs all make a difference, and we will explain the quote if you ask.
What we need to know
Before you ask for a quote, have a think about:
- What the problem is, such as mould, gaps, leaks or cracking
- A few pictures by email, if you can
- The type of property
- Any previous sealing or DIY work
Asking for a quote is easy: tell us what needs doing and where, and roughly how big it is. Photos by email help us understand the job, and we’ll come back to you with a quote.
Frames and glazing around Bexleyheath
With historic houses such as Red House (about 0.4 miles south-west) nearby, there’s older building stock in the area around Bexleyheath as well as newer homes. Where a home is older, older frames set in brick or stone need a sealant that suits them, and sometimes that’s traditional sand mastic. 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.
For an older house near a landmark such as Trinity Baptist Church, frames set in older brick or stone need a sealant that suits the wall as well as the frame. Bexleyheath is in London, so parking needs planning: tell us about permits, visitor bays or off-street space when you book.
Bexleyheath is about 3 miles south-east of Plumstead, in Greater London. Wherever you are in the DA7 postcode area, we cover sand mastic for homes and businesses. Bexleyheath is one of 764 places in Greater London where we work. We also work in London, around 10 miles away.
Postcode districts we cover here for sand mastic: DA7, DA6 and DA16. That includes homes and businesses on Lion Road, Hyde Road and Upton Road. Nearby, we also carry out sand mastic in Upton (1 mile west), Crook Log (1 mile west), Blendon (1 mile south-west), Bexley (1 mile south) and Welling (1 mile west). Further out, we also cover London (10 miles west), City of Westminster (13 miles west), Marylebone (13 miles west), Kensington (15 miles west), St Pancras (12 miles north-west) and Shoreditch (10 miles north-west).
Near you in Bexleyheath
In Bexleyheath, that means homes and buildings near Danson Park, The Volunteer pub and Bexleyheath Academy. There’s a railway station in Bexleyheath itself: Bexleyheath station. Other landmarks nearby include Bexley Hospital (within half a mile west) and Bexley Museum (1.2 miles south-east). Green spaces nearby include Summer Hill and Wansunt Pit.
How the job changes by surface
Tenement and terrace windows
Upper-floor windows need access planning. Let us know the floor and we’ll confirm access.
Sash and case windows
The box of a sash and case window sits in the stone or brick opening. Sand mastic seals the joint round it.
FAQs for Bexleyheath
Can you do sand mastic in Bexleyheath?
Yes. We work across London and the South East, and Bexleyheath is part of that. You can phone 0345 464 0079 or drop us an email and tell us what needs doing, and we’ll send you a clear quote.
Is parking a problem for a job in Bexleyheath?
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.
How long does sand mastic take?
Most jobs take a few hours per window, depending on the condition of the joints, including the preparation. We’ll confirm how long when we quote.
Where is Mr Mastic based?
Our base is in Crawley, and we cover South East England, London and all of Scotland.
Which products do you use?
Products from Arbo and Everbuild, among others, picked for each joint. We explain the product when we quote.
Are you fully insured?
Yes, we’re fully insured.
What exactly is sand mastic?
It’s the traditional filler for the joint round timber windows and doors. It combines sand with a linseed-oil-based binder.
Can I choose the sealant colour?
We help you choose a colour that suits, from white and clear to greys and other shades. The product needed can limit the range.
Other services in Bexleyheath
Why it’s worth doing now in Bexleyheath
If you are redecorating, renew the mastic first. Paint over cracked mastic won’t stop the gaps and traditional guidance is to leave the new mastic unpainted. In a London flat, a failed joint rarely stays your problem alone: water can reach the neighbours below, and gaps in fire-rated joints affect the whole building.
We don’t show prices on the website, because the cost depends so much on the job itself. Call for a quick quote and we’ll talk you through it.
Why Bexleyheath clients choose us
- An ARBOMaster approved applicator
- Anti-fungal sanitary silicone in wet areas
- Fully insured
- Homes, businesses and hotels
Read our cost guide and our reviews.
Signs you need sand mastic in Bexleyheath
Timber frames move with the seasons. That movement opens up the mastic joint little by little.
Common reasons people contact us include:
- Modern sealant on a period surround
- Patchy fillers round a sash window
- Failed mastic on an exposed elevation
- Window mastic to renew ahead of painting
Letting a property close to Bexleyheath station? Then older sash windows in a rental need their mastic kept sound to keep the weather out.
Comparing quotes
- What happens if the job turns out different
- What the quote includes, VAT included or not
- What preparation is included
- What product goes in the joint
How it works
On the day, we start by going over the job with you. Surfaces next to the work are protected before any work begins. Most jobs take a few hours per window, depending on the condition of the joints. For a job in Bexleyheath, parking and access are the things to plan: let us know about parking, the floor we’ll 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.
- We mix the sand mastic and apply it by hand, shaping it to the joint.
- The mastic is finished to sit tidily against the stone or brick.
Before we arrive
- Tell us about access, such as stairs, a lift or high-level joints
- Tell us about any previous sealing or DIY attempts
- Keep pets and children clear of the area while we work
Get a quote
If you are in Bexleyheath and need sand mastic, call 0345 464 0079 or send us an email. Tell us what the problem is and where, and you’ll get a clear quote before we start.
Related advice
What sealant work can’t fix
To be straight with you, some problems need a different trade:
- Timber that has rotted
- Cracked or broken glass
- Sashes that need overhauling
If in doubt, ring 0345 464 0079 or send us an email and we’ll say what we think.
Joints and surfaces we work on
- Brick reveals
- Sash and case windows
- Stone surrounds
- Tenement windows
- Period & listed homes
- Timber door frames