Greater London · England
Welling Sand Mastic
Problem with your window and door surrounds in Welling? We cut out the old, prepare the joints and apply the right sealant.
- Mastic round period door frames that has failed
- Weathered mastic on the most exposed windows
- Mastic that needs renewing before redecorating
How we handle sand mastic in Welling
Across Welling, we renew sand mastic around sash and case windows. Every joint is cleaned out and filled by hand for a neat, traditional finish. We work on timber door frames, tenement windows and sash and case windows, and people most often call us about draughty sash windows at the surround and mastic round period door frames that has failed.
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 Welling.
The work is covered for a year after we finish. If anything is not right with it, call 0345 464 0079 or drop us an email.
- Place
- Welling (DA16, DA15, DA6)
- Region
- Greater London
- Guarantee
- 12 months on all our work
- Quotes
- A clear price before work begins
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
When to call us in Welling
Water gets into small cracks in the mastic and pushes it out. Windows facing the weather tend to go first.
The most common problems we see are:
- Failed mastic on an exposed elevation
- A silicone bead on a sash window that spoils the look
- Window mastic to renew ahead of painting
- Gaps round a timber door in stone or brick
As a London address, Welling can be tricky for parking: let us know about parking bays, permits or a driveway.
Before booking anyone
- How the colour is chosen
- What the quote includes, VAT included or not
- How the joint is cleaned and prepared
- Who does the work, and how experienced they are
Leave it or put it right?
Not every filler suits an old window surround. Sand mastic matches what was there, which can matter on listed and conservation-area homes. In London conversions, one flat’s bathroom is often above another flat’s ceiling, so a small leak from tired sealant can mean a neighbour’s ceiling and a lot of disruption. Putting it right early is much less trouble.
There are no prices on our website, because the cost depends so much on the job itself. Call for a quick quote and we will talk you through it.
Why book with us
- Quality sealants from Arbo and Everbuild
- 12-month guarantee on every job
- Homes, businesses and hotels
- Sanitary silicone with an anti-fungal additive in wet areas
Take a look at our cost guide and customer reviews.
How the job changes by surface
Sash and case windows
On a sash window, the mastic joint shows on the outside, so a neat, even finish matters.
Tenement and terrace windows
Where a building is shared, window work may involve neighbours so it’s worth checking responsibilities.
Towns and villages near Welling
Other services in Welling
Welling homes and the weather
Historic houses like Danson House (about 0.4 miles south-east) are a reminder that the area around Welling has older buildings as well as new. Where a home is older, older timber frames in brick or stone need a different approach from a modern uPVC window. In London conversions and blocks, the lease decides who is responsible for the frames, so it’s worth checking before booking.
Letting a property close to Welling station? Then cracked sand mastic around sash windows lets in the draughts tenants complain about. If you live in an older home near St John's Church, frames set in older brick or stone need a sealant that suits the wall as well as the frame.
Welling is about 9 miles east of London, in Greater London. Wherever you are in the DA16 postcode area, we cover sand mastic for homes and businesses. Our Greater London coverage runs to 764 places, Welling among them. Our London page covers work nearby, about 9 miles away.
Postcode districts we cover here for sand mastic: DA16, DA15 and DA6. Whether your property is on Days Lane, Hook Lane and Lyme Road or a nearby road, we can help. With the A207 close by, Welling is easy for our applicators to reach for sand mastic. If you are just outside Welling, we cover Crook Log (1 mile east), Blendon (1 mile south-east), Upton (1 mile east), Bexleyheath (1 mile east) and West Heath (1 mile north-east). Larger places within reach include London (9 miles west), City of Westminster (12 miles west), Marylebone (12 miles west), Kensington (14 miles west), St Pancras (11 miles north-west) and Shoreditch (9 miles north-west).
Near you in Welling
We work in homes and buildings around Nags Head pub, Danson Park and Bexley Grammar School, among other places. The nearest railway station is Welling station, about 0.5 miles north-west. Other landmarks nearby include Greenwich Castle (5 miles west) and Broadway Shopping Centre (1.6 miles east). For a walk, there’s The Tarn and Summer Hill.
Honest limits
In fairness, some problems need a different trade:
- Crumbling stone or brickwork round the window
- Sash cords, weights and draught-proofing of the sashes
- Planning or listed building consent (your local planning authority decides)
Not sure which it is? You can ring 0345 464 0079 or email us and we’ll tell you honestly.
Surfaces we seal
- Period & listed homes
- Timber door frames
- Brick reveals
- Stone surrounds
- Tenement windows
- Sash and case windows
DIY sealant or a professional job?
What a professional job adds is preparation and the right product. We take joints back to clean, dry surfaces, and the sealant is matched to the joint and its conditions.
Sealing over old silicone is the commonest DIY error. New silicone will not bond to old, so it lifts and traps water and mould underneath. Everything old must be removed first.
How the visit works
Good joint work is mostly preparation, and we do not rush it. Joints are cleaned back and dried before anything new goes in. In total, it usually takes a few hours for a single window, longer for several. For a job in Welling, 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.
- The mastic is mixed, pressed into the joint by hand and shaped.
- The mastic is finished to sit tidily against the stone or brick.
Before we arrive
- Mention any leaks or damp you’ve noticed
- Tell us about access, such as stairs, a lift or high-level joints
- Tell us if parking is tricky
How to get a quote
If you’re in Welling and need sand mastic, phone 0345 464 0079 or drop us an email. Tell us what the problem is and where, and you’ll get a clear quote before we start.
Advice
How to look after the new joints
Once the sealant has cured, a few habits help it last:
- Take care around the mastic when scraping paint
- Keep sills and gutters clear so water drains away
- Have rotten timber repaired before new mastic goes in
- Check with your local planning authority if your home is listed
Look at the mastic when you look over the windows. Catching cracks early keeps repairs small.
An open joint round the box lets weather through. Left, the gap tends to get bigger.
Common questions in Welling
Is Welling in your area for sand mastic?
Yes. We work across London and the South East, and Welling is part of that. Just ring 0345 464 0079 or email us with a few details of the job, and we will give you a clear price.
Can you help a landlord with a rental near Welling station?
Yes, we work for letting agents and landlords. You can ring 0345 464 0079 or email us with the address and a few details, and we’ll give you a fixed price before we start.
Can you match the sealant colour?
We help you choose a colour that suits. The product needed can limit the range.
Is sand mastic better than silicone for my windows?
We will help you decide. Sand mastic suits many period homes and newer frames suit modern sealant.
Can you seal over the old sealant?
No, it won’t last. It can look neat for a few weeks, but the new bead soon lifts. The old sealant has to come out completely.
Are you an approved applicator?
Yes. We’re ARBOMaster approved, the scheme for applicators of Arbo sealants.
Do I need to be at home?
Access is agreed with you when the job is booked. Indoors, that generally means someone at home.
Will there be a smell?
Possibly a little. It fades as the sealant cures.