Greater London · England
Pentonville Window Mastic
Mastic around window and door frames, sills and patio doors for homes and businesses in Pentonville and across Greater London. Fully insured, ARBOMaster approved and guaranteed for a year.
- Water coming in at the bottom corners of a door
- Untidy mastic left by window fitters
- Cold air getting in at the frame edge
Why deal with it now?
Running fresh sealant over the old joint is tempting, but new sealant can’t bond to old, crumbling mastic. It peels before long, and water still gets in behind. Proper resealing starts with removing the old joint. In a London flat, a failed joint rarely stays your problem alone: water from a shower or window joint can reach the flat below, and gaps in fire-stopping matter to everyone in the building.
Leaving a failed joint usually makes the job bigger, not smaller, because water and mould keep working on it. If you are unsure, phone 0345 464 0079 or send us an email and we will give you an honest view and a quote.
Why book with us
- Domestic, commercial and hotel work
- An ARBOMaster approved applicator
- Full insurance on every job
- Over 20 years’ experience
See what affects the cost and what customers say.
Window mastic for homes and businesses in Pentonville
Frames and walls do not move together. Plastic and aluminium frames move with the temperature, while masonry stays fairly still. That is why the joint needs a flexible, low-modulus sealant rather than something rigid. If you are dealing with damp patches on the reveal after heavy rain and a bead that doesn’t match the frame, we can help, whatever the surface.
From mansion-block windows to modern glazing in new flats, London has every kind of frame. Over the years, the sealant around them shrinks, cracks and pulls away, which is when draughts and damp patches appear in homes in Pentonville.
Every job is covered by our one-year guarantee.
- Where
- Pentonville (N1, N1P, EC1V)
- Wider area
- Greater London
- Cover
- One year on every job
- Price
- A clear price before any work starts
- Call
- 0345 464 0079
- Last updated
- 26 October 2026
Also near Pentonville
What else we do in Pentonville
Pentonville questions
Do you cover Pentonville for window mastic?
Yes, Pentonville is within the area we cover. We work across London and the South East. Just ring 0345 464 0079 or send us an email with a few details of the job, and we will give you a clear quote.
I let a flat near Essex Road station. Can you help?
Yes, rental work is part of what we do. Just phone 0345 464 0079 or drop us an email and tell us about the property, and we’ll give you a clear quote.
Do you do commercial work?
Yes. Hotels, offices and other businesses use us, and we are fully insured.
Can you do the inside joint as well?
Yes. Indoors, we seal between the frame and the plaster or reveal, using a paintable sealant if you want to decorate.
Does someone need to be in?
If the work is inside, we need someone to let us in. Once we have agreed the job, you don’t need to watch us work.
Can you seal over the old sealant?
No. Fresh sealant doesn’t stick to old sealant, and it traps any mould or water underneath. We remove it all first.
How long before the joint can be used?
Most sealants are touch-dry well before they’re fully cured. We’ll give you the cure time for the product we used before we leave.
Do you have sealant for grey or black windows?
Yes, in most cases. Tell us the frame colour when you get in touch and we will use the nearest match.
How to look after the new joints
Simple care keeps the joints in good condition. We recommend:
- Make sure the drainage slots aren’t blocked
- Keep paint off silicone joints
- Ventilate rooms so frames don’t stay wet inside
- Repaint timber before it’s bare
A yearly look round the frames is enough. Cracks and lifting edges are easy to spot early.
A small gap around a frame only grows. As old mastic keeps shrinking, the gap widens, and a cold room gets colder. Resealing closes it.
What affects the quote in Pentonville
Your quote is based on your job. We take into account:
- Whether there’s mould to deal with
- Whether the work is at height
- How much old sealant there is and how hard it is to remove
- Working hours on commercial sites
Homes and businesses are quoted the same way: the amount of work, the access and the products needed, along with when we can work on site. Call for a quick quote and we will explain what it covers.
What to tell us for a quote
To make quoting easier, please include:
- The type of property
- The rough size of the job
- Where the property is
- What the problem is, such as mould, gaps, leaks or cracking
For a quick quote, get us on the phone, or email us if that’s easier. Tell us about the joints that need doing and we will talk you through the work before giving you a price.
What we can’t put right
It helps to know what we can’t do too:
- A failed sealed unit that has misted up
- Broken hinges, locks or handles
- Draughts through the window seals rather than the frame
Not sure which it is? You can call 0345 464 0079 or drop us an email and we will tell you honestly before you book.
Surfaces we seal
- uPVC windows
- Window sills
- Timber windows & doors
- Composite doors
- Patio & French doors
- Aluminium frames
How it works
Good joint work is mostly preparation, and we don’t rush it. Joints are cleaned back and dried before anything new goes in. In total, it usually takes a few hours for a handful of frames, longer for a whole house. In Pentonville, as in most of London, parking needs a little planning. A visitor permit or a nearby bay makes the visit run more smoothly.
- First, we confirm safe access to each frame.
- All the failed sealant is cut away.
- The surfaces are cleaned and left dry, and primed where the sealant calls for it.
- Backing rod fills deep voids and the sealant goes in on top.
- We tool the joint so water runs off, then clear up.
How to prepare
- Clear the area around the work
- 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
Asking for a quote is easy: tell us what needs doing and where and its rough size. Photos by email help us understand the job.
Related advice
Can I do it myself?
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, and the work is guaranteed for a year.
If you’re set on DIY, put the effort into preparation: take out all the old sealant, make sure the joint is clean and dry, and give it the full cure time. If it fails, we can still redo it.
What the job involves on each surface
uPVC windows
uPVC expands and contracts noticeably with temperature, so we use a flexible, low-modulus sealant. White is the usual colour, with brown, anthracite grey and black for coloured frames.
Aluminium frames
Coated aluminium needs a compatible sealant and we avoid acetoxy silicones, which can react with some metals. Neutral-cure sealant is the safe choice.
Window mastic in Pentonville: local notes
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. With historic houses such as Dr Johnson's House (about 1.4 miles south) nearby, there’s older building stock in the area around Pentonville as well as newer homes. Where a home is older, older timber frames in brick or stone need a different approach from a modern uPVC window.
As a London address, Pentonville can be tricky for parking: let us know about parking bays, permits or a driveway. If you let a flat or house near Essex Road station, sound mastic around windows and doors keeps out the draughts and damp that tenants notice first. If you look after a building such as St John Evangelist RC Primary School, the mastic around its windows and doors needs looking after like any other building’s.
Pentonville is about 1 mile north-east of St Pancras, in Greater London. We provide window mastic to homes and businesses in Pentonville and the surrounding area. Across Greater London, we cover 764 places, and Pentonville is one of them.
Work in N1, N1P and EC1V works the same way as everywhere else we cover. You will find streets such as City Road, Noel Road and Dewey Road, all of which we cover. You will find Pentonville on the A1200, which makes it straightforward to reach with everything needed for window mastic. Other places close to Pentonville include Angel (1 mile south-west), Islington (1 mile north), Clerkenwell (1 mile south), Barnsbury (1 mile north-west) and St Pancras (1 mile south-west). Within a short drive, we also cover City of Westminster (3 miles south-west), Kensington (5 miles south-west), Walthamstow (5 miles north-east), Hampstead (4 miles west), Ruislip (13 miles west) and Brompton (4 miles south-west).
Near you in Pentonville
Locally, jobs take us to homes and businesses close to Islington Green School, The Camden Head Public House and Pilsudski Institute of London. Also close by are City of London Academy Islington (under half a mile east) and Barnard Park (under half a mile west). The closest station to Pentonville is Essex Road station, roughly 0.5 miles north-east. Well-known places in the area include Museum of Funeral History (0.7 miles south-west) and Brunswick Centre (1.2 miles south-west). The countryside around Pentonville includes Ludgate Hill and St. James's Park Lake.