Greater London · England
Northolt Sand Mastic
Traditional burnt sand mastic around sash and case windows and doors in stone and brick for Northolt, backed by a 12-month guarantee. Ask us for a quote.
- Gaps where the frame meets the masonry
- Old sand mastic that has cracked, crumbled or fallen out
- Mastic round period door frames that has failed
Do you need sand mastic in Northolt?
Timber swells and shrinks with the weather. The movement cracks the mastic little by little.
The most common problems we see are:
- Open joints round the window box
- Window mastic to renew ahead of painting
- Gaps round a timber door in stone or brick
- Failed mastic on an exposed elevation
Homes close to St Richard's Church include some older properties, and frames set in older brick or stone need a sealant that suits the wall as well as the frame.
Comparing quotes
- Whether the sealant suits the joint
- What preparation is included
- Whether you can choose the colour
- Is the old sealant removed completely?
Sand mastic in Northolt, done properly
If your home is listed or in a conservation area, check with your local planning authority whether consent is needed for work to windows. Like-for-like sand mastic is often the preferred finish. If you’re dealing with gaps where the frame meets the masonry and cracked mastic round a front door frame, we can put it right.
Many London homes are flats, with windows high above the street. Who looks after the outside of the frames can depend on the lease, so check that first.
The work is guaranteed for twelve months. If there’s a problem with our work within the year, let us know and we will sort it.
- Where
- Northolt (UB5, UB6)
- Wider area
- Greater London
- Guarantee
- One year on every job
- Quotes
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
How the job changes by surface
Timber door frames
Door frames get knocked and soaked and the mastic can crack early. We rake it out and renew it.
Brick reveals
An open joint at a brick reveal lets weather in. Renewing the mastic closes it.
Towns and villages near Northolt
Also in Northolt
Leave it or put it right?
Not every filler suits an old window surround. Sand mastic matches what was there and that can be important for listed homes. In older London homes, water behind a failed joint soaks into brick and timber without much sign, and by the time it shows on a wall or ceiling in Northolt, the repair is bigger than the sealant job would have been.
Doing several joints on one visit is usually more efficient than separate visits, so it’s worth mentioning everything you’d like done. You will get one clear quote for the whole job.
What you get with us
- Quality sealants from Arbo and Everbuild
- Neat joints and a tidy finish
- Experience in homes, commercial sites and hotels
- Every job guaranteed for a year
Take a look at our cost guide or what customers say.
The process
Most of a good job is in the preparation, so that is where we spend the time. Every joint is cleaned and dried before new material goes in. In total, it usually takes a few hours for a single window, longer for several. Many London jobs are in flats, so we come ready for stairs, narrow hallways and shared entrances. Mention any building rules, key holders or managing agents when you book.
- Each surround is checked first.
- The joint is raked out and cleaned.
- Large voids are packed out.
- New sand mastic is applied and shaped by hand.
- We finish the mastic to a tidy line.
Before we arrive
- Tell us about any previous sealing or DIY attempts
- For indoor joints, keep the area dry beforehand if you can
- Mention any tricky access
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, and we’ll come back to you with a quote.
Advice
Frames and glazing around Northolt
Historic houses like Northolt Manor (about 0.3 miles south) are a reminder that the area around Northolt 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. The South East is one of the drier parts of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
For landlords with property near Northolt Park station, cracked sand mastic around sash windows lets in the draughts tenants complain about. Northolt is in London, so parking needs planning: let us know about parking bays, permits or a driveway.
Northolt is about 2 miles south-west of Harrow, in Greater London. Across the UB5 area, our applicators can take on sand mastic. Our area takes in 764 places across Greater London, large and small. Our London page covers work nearby.
Postcode districts we cover here for sand mastic: UB5 and UB6. Sand mastic is available to properties on Church Road, Eastcote Lane North and Tenby Gardens. We also cover South Ruislip (1 mile north-west), Greenford (1 mile south-east), South Harrow (1 mile north-east), Yeading (2 miles south-west) and Yiewsley (2 miles south-west). Further out, we also cover London (12 miles east), City of Westminster (10 miles east), Marylebone (10 miles east), Kensington (8 miles south-east), St Pancras (11 miles east) and Shoreditch (13 miles east).
Around Northolt
Typical jobs here are in homes near Northala Fields, The Greenwood Public House and Northolt High School and the streets around them. The nearest railway station is Northolt Park station, about 0.7 miles north-east of the centre. A little further out are Heath Robinson Museum (3.1 miles north) and Clementine Churchill Hospital (2 miles north-east). Not far away are Islip Manor Meadows and Northala Fields.
Your questions about sand mastic in Northolt
Do you work for landlords with property near Northolt Park station?
Yes. We work for letting agents and landlords as well as homeowners, and several properties can be quoted together. You can phone 0345 464 0079 or email us with the details for a clear quote.
Is Northolt in your area for sand mastic?
Yes, Northolt is within the area we cover. Our work covers London and the South East. You can phone 0345 464 0079 or send us an email and tell us what needs doing, and we’ll send you a clear quote.
Is it worth trying it myself?
That depends on the joint. Work at height, movement joints, fire-rated gaps and large areas are best left to a professional, while a short indoor joint may be within reach.
How long does sand mastic take to go off?
Not right away. It skins first and hardens fully later and we will give you an idea for your job.
How long does sand mastic take?
That depends on how much there is to do, but most jobs take anything from a few hours to a full day, depending on how many windows. We’ll tell you when we quote.
What do you need from me for a quote?
Where the job is, what the problem is and roughly how big it is. If you can, email a few photos.
Is it OK to seal over old sealant?
No, and we never do. It can look neat for a few weeks, but the new layer lifts away from the old one. Removing the old sealant completely is the only lasting way.
What do you put in the joint?
The product depends on the job: anti-fungal sanitary silicone in wet areas, and other sealants where joints move or face the weather. We use products from Arbo and Everbuild.
Keeping the joints in good condition
Once the sealant has cured, a few habits help it last:
- Don’t run silicone over sand mastic
- Look over the window mastic once a year
- Ask the planning authority about consent for listed or conservation-area homes
- Get any rot dealt with first
Check the mastic when you check the paintwork. Small cracks are easier to deal with early.
Fine cracks show the mastic is starting to fail. It’s easier to renew it before it drops out.
Quotes for sand mastic in Northolt
Every job gets its own quote. This is what makes a difference:
- Access and height
- Any mould that needs treating
- The type of sealant required
- The number of rooms or windows
What you pay reflects the work, not a rough estimate. That is why we ask a few questions first.
Helping us quote
A few details help us give you an accurate quote. When you ask for a quote, tell us:
- Where the job is, and your postcode
- Photos by email, if that’s easy
- What’s wrong with the joints now
- How we’d reach the joints
We do not publish a price list, as no two jobs are quite the same. Instead, your job gets its own clear quote. To get started, ring 0345 464 0079 or send us an email.
Can I do it myself?
The biggest DIY mistake is sealing over old sealant. Silicone doesn’t stick to old silicone, so it lifts and traps water and mould underneath. All the old material has to come out first.
What a professional job adds is preparation and the right product. Joints are cleaned back to sound surfaces and dried, and the sealant is matched to the joint and its conditions.