Greater London · England
External Mastic in Temple Fortune
We cover Temple Fortune for sealing brickwork movement joints, render, cladding and façade joints. Old sealant removed completely, joints prepared properly.
- Panel joints letting water in
- Old sealant gone brittle and cracked
- Movement joints with cracked, split or missing sealant
When to call us in Temple Fortune
Buildings move more than people expect. Clay bricks expand slightly over their life, concrete and block shrink, and everything moves with temperature and wet. All of that ends up in the joint sealant.
Keep an eye out for any of the following:
- Failed sealant between panels on a façade
- Joints where the bead has come unstuck
- Brick movement joints where the sealant has split
- Movement joints filled with mortar instead of sealant
Letting a property close to Brent Cross West station? Then outside joints that have cracked can let damp into a rental, so check them between lets.
Questions to ask before booking
- What happens if they find a problem under the old sealant
- What the cure time is
- How the surfaces are prepared before sealing
- Whether you can choose the colour
How we handle external mastic in Temple Fortune
We’re ARBOMaster approved applicators, and each external joint gets a sealant suited to it. Porous or awkward surfaces are primed where the sealant needs it. If you’re dealing with cracked joints where brick meets render or frames and weathered mastic that no longer stretches, we can help, whatever the surface.
Modern London flats rely on sealed movement joints and cladding joints. Older terraces have their own weak points: gutter joints, roofline trims and the joint where an extension meets the original wall.
Our work is backed for twelve months, in Temple Fortune and everywhere else we cover.
- Where
- Temple Fortune (NW11, NW4, N3)
- Wider area
- Greater London
- Guarantee
- One year on every job
- Quote
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
Why act early in Temple Fortune
An open joint keeps letting water into the wall with every downpour. In cold weather, frost can damage wet brick and render around the joint, so the problem grows beyond the joint itself. Converted houses in London often have a bathroom above someone else’s living room, so a small leak from tired sealant can mean a neighbour’s ceiling and a lot of disruption. Dealing with it early is far simpler for homes in Temple Fortune.
A failed joint rarely gets cheaper to fix by waiting. If you’re not sure whether it needs doing, phone 0345 464 0079 or drop us an email and we’ll give you an honest view and a quote.
Why choose Mr Mastic in Temple Fortune
- Domestic, commercial and hotel work
- A choice of colours where the product allows
- Approved under the ARBOMaster scheme
- A sealant colour to suit the surroundings
How to look after the new joints
How long the joints last depends on use and care. We suggest:
- Make sure movement joints aren’t pointed over
- Show decorators and builders where the movement joints are
- Keep high-pressure jets off the joints
- Walk round the building once a year and look at the joints
Look over the joints once a year, ideally after winter. Watch for splits, edges coming away or growth in the joint.
Gaps, plants or missing sealant in a joint are worth getting looked at. Early work is quicker and leaves a better finish.
Also near Temple Fortune
What else we do in Temple Fortune
For landlords and businesses
If you manage several properties in or around Temple Fortune, jobs at different addresses can go on one quote. Send us the addresses and the work at each, and pictures by email help.
Water getting past a failed joint can damage the building, which is a bigger problem in a rented property. Keeping joints in good order is simple maintenance.
Walls and rooflines in Temple Fortune
With historic houses such as Heath Hall (about 1.3 miles east) nearby, there’s older building stock in the area around Temple Fortune as well as newer homes. In older buildings, older walls and rooflines need a sealant that moves with them and suits the material. In terraces and conversions, gutters and walls are often shared with the neighbours, so it’s worth agreeing who is responsible before work starts.
Homes close to Saint Mary and Archangel Michael Church include some older properties, and older walls, gutters and the joints where extensions meet them need a flexible sealant. Temple Fortune is in London, so parking needs planning: tell us about permits, visitor bays or off-street space when you book.
Temple Fortune is about 1 mile south-west of Finchley, in Greater London. Across the NW11 area, we cover external mastic for homes and businesses. Temple Fortune is one of 764 places in Greater London where we work. We also work in London, around 7 miles away.
Jobs for external mastic in NW11, NW4 and N3 is quoted and booked the same way as anywhere else. External mastic is available to properties on Hoop Lane, Bridge Lane and Limes Avenue. Main roads around Temple Fortune include the A598, so getting to you is simple. We also cover the places around Temple Fortune: Golders Green (1 mile south), Hampstead Garden Suburb (1 mile east), East Finchley (1 mile north-east), North End (1 mile south-east) and Childs Hill (1 mile south). Further out, we also cover London (7 miles south-east), City of Westminster (5 miles south-east), Marylebone (5 miles south-east), Kensington (6 miles south), St Pancras (5 miles south-east) and Shoreditch (6 miles south-east).
What’s near Temple Fortune
In Temple Fortune, that means homes and buildings near The Henrietta Barnett School, The King Alfred School and Princes Park. The nearest railway station is Brent Cross West station, roughly 1.5 miles south-west of the centre. A little further out are Highgate Private Hospital (1.9 miles east) and Jewish Museum - Finchley (1 mile north-east). The countryside around Temple Fortune includes Darland's Lake and Parliament Hill.
Should I try it myself first?
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. Everything old must be removed first.
If you’ve already had a go yourself, that’s fine. We remove it and do the joint properly.
What happens on the day
Our applicators work methodically: protection first, then preparation, sealing and a tidy-up. For most jobs that takes a few hours to a few days, depending on the length of joint and the access, and the area is left clean. In Temple Fortune, flats, stairs and shared entrances are part of the routine. Mention any building rules, key holders or managing agents when you book.
- We start by checking each joint, agreeing the ones to redo and how we’ll reach them.
- We cut out the failed sealant and rake out any dirt or growth.
- The joint faces are cleaned and primed where the sealant needs it.
- Closed-cell backing rod is fitted to set the depth and stop three-sided bonding.
- A flexible exterior sealant is applied and tooled in a colour to suit the wall.
Getting ready for the visit
- Tell us about any water getting in
- Tell us about access, such as stairs, a lift or high-level joints
- Mention any parking rules near the property
How to get a quote
Want a quote for external mastic? Please ring 0345 464 0079 or drop us an email and tell us about the job. We’ll explain what we’d do and send you a clear quote before any work starts.
Related advice
FAQs for Temple Fortune
Do you work for landlords with property near Brent Cross West station?
Yes, we work for letting agents and landlords. You can phone 0345 464 0079 or send us an email with the address and a few details, and we will give you a fixed price before any work starts.
Can parking be tricky for a visit in Temple Fortune?
Parking in Temple Fortune, as in most of London, takes a little planning: a visitor permit or a bay close to the door helps a lot, so mention what’s available when you book.
What colours does the sealant come in?
Exterior sealants are made in a range of colours, from greys and browns to whites and stone shades. We pick the one that suits your wall best so the joint doesn’t draw the eye.
Where are you based?
We work from Crawley. Our applicators cover Temple Fortune, along with the rest of our area.
Do you take out the old sealant first?
Yes. All of the old material is cut out and the joint cleaned before resealing.
What sealant do you use?
Each joint gets the product that suits it. Movement, water and weather all affect the choice, and we’ll explain our choice.
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.
Do you work at height?
That depends on how high the joints are and the ground below. Low-level joints are straightforward; for higher work, tell us about the building and we’ll confirm what’s needed.
What affects the cost of external mastic
Jobs vary more than people expect. The main factors:
- Whether old sealant or filler has to be cut out
- Whether there’s mould to deal with
- Access and height
- Which sealant suits the joint
Doing several joints on one visit is generally more efficient than separate visits, so it’s worth mentioning everything you’d like done. We’ll give you a clear quote for the lot.
What to tell us for a quote
Photos by email are helpful but not essential. Try to tell us:
- Roughly how big the job is
- Any access issues, like height or stairs
- A few pictures by email, if you can
- The type of property
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 photos by email if you can.