Greater London · England
Northfields Sand Mastic
Sand mastic across Northfields and nearby, with old sealant always removed completely and a 12-month guarantee.
- Cracked mastic round a front door frame
- Weathered mastic on the most exposed windows
- Silicone on a period window that looks wrong
What affects the quote in Northfields
The price is agreed before any work begins. It’s based on:
- Which sealant suits the joint
- How many rooms, windows or areas are involved
- Any working-time requirements on site
- Mould in or behind the old joints
A failed joint rarely gets cheaper to fix by waiting, as water and mould keep getting in. If you are unsure, phone 0345 464 0079 or drop us an email and we’ll give you an honest view and a quote.
Asking for a quote
Photos by email are helpful but not essential. Try to tell us:
- If it’s domestic, commercial or a hotel
- What the problem is, such as mould, gaps, leaks or cracking
- Where the property is
- The rough size of the job
For a quick quote, get us on the phone, or send an email if you’d rather. Describe what needs sealing and we’ll explain what’s involved before giving you a price.
Sand mastic in Northfields, done properly
If your home is listed or in a conservation area, check with your local planning authority if consent is needed before window work. Sand mastic is often favoured as a like-for-like material. If you have gaps where the frame meets the masonry and mastic worn away on windows facing the weather, we can put it right, on brick reveals, period & listed homes and tenement windows alike.
Much of London’s older housing was built with timber sash windows, some still in place and some long since replaced. Whatever is in the opening now, the joint between frame and wall is what keeps the weather out.
Our work is backed for twelve months, and the guarantee is the same wherever you are.
- Where
- Northfields (W5, W13, TW8)
- Region
- Greater London
- Cover
- A year, on every job
- Quotes
- A clear quote up front
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
What sealant work cannot fix
Some problems need a builder, plumber or other trade rather than us:
- Sashes that rattle, stick or won’t open
- Cracked or broken glass
- Decisions on consent for listed homes
Not sure which it is? You can phone 0345 464 0079 or email us and we’ll tell you honestly before you book.
What we seal
- Period & listed homes
- Brick reveals
- Tenement windows
- Stone surrounds
- Sash and case windows
- Timber door frames
DIY versus a professional finish
Overfilling a joint is a classic DIY mistake. A thick, smeared bead looks untidy and does not move well, and the joint depth matters as much as the finish.
If you’ve already had a go yourself, that is fine. We remove it and do the joint properly, so just mention it when you contact us.
Why deal with it now?
Gaps round a sash window let in rain and draughts. Water can get to the frame and the masonry, so dealing with it now protects both. In a flat in Northfields, failed sealant seldom stays inside your own four walls: water from a shower or window joint can reach the flat below, and gaps in fire-stopping matter to everyone in the building.
Homes and businesses are quoted the same way: the amount of work, how we reach it and what it needs. Ask us for a quote and we will go through it with you.
Why Northfields clients choose us
- Over 20 years’ experience
- Fully insured
- Arbo and Everbuild products
- Experience in homes, commercial sites and hotels
Take a look at what affects the cost or what customers say.
Nearby places to Northfields
Also in Northfields
Questions from Northfields
Can parking be tricky for a visit in Northfields?
Parking in Northfields, as in most of London, takes a little planning: a visitor permit or a nearby bay makes the day run more smoothly.
Do you cover Northfields for sand mastic?
Yes, Northfields is within the area we cover. We work across London and the South East. You can call 0345 464 0079 or send us an email and tell us what needs doing, and we’ll send you a clear quote.
Do you take out the old sealant first?
Yes, always, and completely. New silicone does not stick to old silicone, so the joint is cleaned back first.
What sealant do you use?
The product depends on the job: anti-fungal sanitary silicone in wet areas, and other sealants where joints move or face the weather. Brands we use include Arbo and Everbuild.
Do you have insurance?
Yes. We’re fully insured, and we can confirm the details when we quote.
Do you work for hotels and businesses?
Yes. Hotels, offices and other businesses use us.
Is it worth trying it myself?
For a simple, easy-to-reach joint, a careful DIYer can do a reasonable job. The usual mistakes are sealing over old sealant, sealing a damp joint and using too much.
Where are you based?
We work from Crawley. We cover Northfields and the rest of Greater London, along with the rest of our area.
How the job changes by surface
Brick reveals
Sand mastic is also used where timber frames meet brick. It suits older brickwork.
Period and listed homes
Period homes look their best with traditional materials.
Windows and doors in Northfields
In a converted house or block, who looks after the windows depends on the lease, so check that before booking. 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 site and facilities teams at buildings such as Mount Carmel Catholic Primary School, its window and door frames need their mastic kept sound, just like a home’s. As a London address, Northfields can be tricky for parking: let us know about parking bays, permits or a driveway. For landlords with property near Brentford station, any sash windows need sound mastic to keep draughts and rain out.
Northfields is about 1 mile south of Ealing, in Greater London. Across the W5 area, we cover sand mastic for homes and businesses. Northfields is one of 764 towns and villages in Greater London where we work. There’s also a page for London, about 9 miles away.
Our applicators cover all of W5, W13 and TW8 for sand mastic. Whether your property is on Burns Road, South Road and Elers Road or anywhere close by, our applicators can take on the job. Main roads around Northfields include the A3002, so getting to you is simple. If you are just outside Northfields, we cover Brentford (1 mile south-east), Gillette Corner (1 mile south-west), Brentford End (1 mile south), Osterley (2 miles south-west) and Spring Grove (2 miles south-west). Larger places within reach include London (9 miles east), City of Westminster (7 miles east), Marylebone (7 miles east), Kensington (5 miles east), St Pancras (9 miles east) and Shoreditch (10 miles east).
What’s near Northfields
We work in homes and buildings around Ealing Fields High School, Great Ealing School and Ealing Park Tavern and the streets around them. You will also find Library for Iranian Studies (1.8 miles east) and Lammas Park (less than half a mile north). The nearest railway station is Brentford station, about 0.8 miles south of the centre. Other landmarks nearby include Gunnersbury Park House - Large Mansion (1.2 miles east) and Treaty Centre (3 miles south-west). The countryside around Northfields includes Middle Lake and Long Wood.
Keeping the joints in good condition
Once the sealant has cured, a few habits help it last:
- Avoid heavy scraping on the mastic joint
- Renew mastic before redecorating the windows
- Check with your local planning authority if your home is listed
- Ask us before painting near the mastic
Avoid painting over the new mastic, which is the traditional advice. If you’re redecorating, ask us first.
Small cracks are a sign the mastic is ageing. Renewing it then is simpler than waiting until it falls out.
How the visit works
At the end, we look at the finished work together. The visit itself generally takes a few hours for a single window, longer for several, depending on the size of the job. In Northfields, as in most of London, parking needs a little planning. It helps if you can point us to a visitor permit or a bay close to the door.
- We look at the surrounds with you and agree the joints to renew.
- Old mastic and any loose material are raked out.
- We pack any deep voids first.
- We apply the mastic by hand and shape it.
- We dress the finish so it sits neatly against the masonry.
Before we arrive
- Clear the area around the work
- Let us know if you’ve seen damp or leaks
- Mention any parking rules near the property
Get a quote
The more we know about the job, the more useful the quote. Tell us where the job is, what’s wrong and how much there is, and add pictures by email if you can.