South East England and London

Window Mastic in Greater London

Window mastic in all 764 towns and villages of Greater London, done properly, quoted clearly before any work starts and a one-year guarantee.

Call 0345 464 0079

Get a quick quote

Where we work in Greater London

Mastic around window and door frames, sills and patio doors. Pick your town below to see the details for your area, and get in touch for a quick quote.

Largest places

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Postcode districts

Window mastic across Greater London: what to expect

Colour matters on a frame. White, brown, anthracite grey, black and clear sealants are all available, so the line suits the frame instead of standing out. Common call-outs are for a bead that doesn’t match the frame and mastic that has split away from the wall, on composite doors, uPVC windows and window sills.

Most of a good job is in the preparation, so that is where we spend the time. Joints are cleaned back and dried before anything new goes in. In total, it generally takes a few hours for a few frames, or a day or more for a whole house.

We check each frame and agree which ones need doing.
We remove the old mastic and clean the frame and the wall.
Deep gaps are filled with backing rod to set the depth.
New exterior sealant goes on in a matching colour and is tooled smooth.
Every joint is checked before we leave.

What you will pay

A failed joint rarely gets cheaper to fix by waiting, as water and mould keep getting in. If you are not sure whether it needs doing, phone 0345 464 0079 or email us and we’ll give you an honest view and a quote.

Why choose Mr Mastic

A sealant colour to suit the surroundings
More than 20 years in sealant work
Trusted Arbo and Everbuild sealants
Experience in homes, commercial sites and hotels

Get a quote

Quotes start with a quick conversation. Tell us what’s wrong, where it is and how much there is. When it suits you, call 0345 464 0079 or send us an email.

Near you in London

In London, that means homes and buildings near St Mary-at-Hill, St George the Martyr and The BFI Reuben Library, among other places. Nearby too are Trinity Arms Public House (less than half a mile south-east), Ark Globe Academy (less than half a mile south), Charles Dickens Primary School (within half a mile north-west) and Newington Gardens (under half a mile south). There’s a railway station in London itself: Elephant & Castle station. Nearby you will also find Surrey Dispensary (less than half a mile south-east) and Baynard's Castle (0.9 miles north). Open spaces near London include Bellenden Road Nature Garden and St. James's Park Lake.

Local schools include London School of Musical Theatre (within half a mile west)

Windows and doors across Greater London

Homes across Greater London range from period properties with timber or sash windows to new builds with uPVC. Walls facing the weather take the most punishment.

Most of the South East has hard water, so limescale builds up on sealant, grout and fittings. Whatever the job in Greater London, surfaces are cleaned back properly before new sealant goes in.

London: If you let a flat or house near Elephant & Castle station, cracked frame mastic tends to show up as a draught or damp complaint, so it’s worth checking between lets. For site and facilities teams at buildings such as Charles Dickens Primary School, larger buildings have plenty of frames, and the mastic around each one ages.

Signs you need window mastic

Timber windows bring their own problems. Old mastic gets painted over and cracks under the paint, and timber moves with moisture as well as temperature.

These are the problems we’re asked about most:

Gaps between the frame and the inside reveal
Untidy mastic left by window fitters
Cold air getting in at the frame edge
White mastic on grey or black frames

What happens if it’s left?

Draughts and leaks don’t always mean new windows. Where the frames are sound, new mastic usually deals with draughts and leaks at the edges. Problems with the glass or gaskets are for a window company, and we’ll say so.

Questions to ask before you book

What the quote includes, VAT included or not
Whether the sealant suits the joint
Whether they’re fully insured
How long the guarantee is

Landlord and commercial work in Greater London

Housing providers, facilities teams and property managers book us too across Greater London. Several sites can be quoted together, and we’re fully insured.

A neglected joint can let water reach the structure, which matters even more when someone else lives there. Resealing at the right time is simple maintenance.

Should I try it myself first?

Some jobs are best left to a professional: high-level joints, fire-rated gaps, external movement joints and big jobs need the right product, the right access and the right method.

Sealing over old silicone is the commonest DIY error. Silicone does not stick to old silicone, so it lifts and traps water and mould underneath. Everything old must be removed first.

Quotes for window mastic in Greater London

Your quote is based on your job. We take into account:

Whether old sealant or filler has to be cut out
The number of rooms or windows
Whether there’s mould to deal with
Whether the work is at height

Some things make a job bigger or smaller: the old material and how easily it comes out, any mould to treat, and whether we need extra access for height. We take all of that into account in your quote.

What to tell us for a quote

When you call or email, it’s useful to know:

Whether it has been sealed before
Pictures of the joints, sent by email
Access, such as stairs, a lift or height
Whether it’s a home or a business

Need a quote? Please ring 0345 464 0079 or email us and tell us about the job. You’ll know what we plan to do, and what it will cost, before any work begins.

FAQs for Greater London

Do you take out the old sealant first?

Yes. We cut out all the old sealant and clean the joint before resealing.

Do you come to Greater London?

Yes. We work in Greater London. To book, phone 0345 464 0079 or email us.

Will you leave a mess?

Very little: the area around the joints is protected first, and we tidy up before we go.

How long before the joint can be used?

Many sealants skin over quickly but take longer to cure fully. We will tell you how long to leave the joint before we leave.

Where are you based?

Mr Mastic is based in Crawley. Our applicators cover Greater London, along with the rest of our area.

What sealant do you use?

Each joint gets the product that suits it. Where it moves, gets wet or faces the weather makes a difference, and we will tell you what we are using.

Do you work on first-floor windows?

Yes, where they can be reached safely. Let us know about access when you ask for a quote and we will plan for it.