Greater London · England
St Johns Gutter Sealing
Professional gutter sealing in and around St Johns, with every bit of old sealant taken out first and a 12-month guarantee.
- Streaks down the brickwork from a leaking joint
- Fascia boards with gaps between them
- Leaking gutter joints and stop ends
Keeping the joints in good condition
No joint lasts for ever, but care makes a real difference. Our tips:
- Rest ladders on the wall, not the gutter
- Keep the gutters clear of debris
- Have sagging gutters refixed early
- Look at the gutters while it’s raining
Keep downpipes clear, so water can get away. Blockages push water back along the gutter.
A drip from a gutter joint will not stop on its own. The same spot gets soaked every time it rains and that can cause damp inside.
Gutter sealing for homes and businesses in St Johns
Garage door frames let rain in when the sealant around them fails. The frame joint is cut out and resealed with an exterior sealant. If you have garage door frames letting rain in and water dripping where gutter sections meet, we can put it right.
Newer London blocks are built with movement joints in brick and render, and with cladding joints sealed with mastic. Older terraces have their own weak points: gutter joints, roofline trims and the joint where an extension meets the original wall, and both kinds of building are found across London.
You get a one-year guarantee, the same in St Johns as everywhere else we work.
- Location
- St Johns (SE13, SE10, SE8)
- Region
- Greater London
- Cover
- One year on every job
- Price
- A clear quote up front
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
How the visit works
On the day, we look over the joints with you first, so there are no surprises. Surfaces next to the work are protected before we start. Most jobs take anything from an hour or two to a few hours. For a job in St Johns, parking and access are the things to plan: tell us about permits, visitor bays or off-street space, which floor we are working on and whether there’s a lift.
- First we agree which joints need sealing.
- Each joint is cleaned and any old sealant removed.
- The joints are dried.
- The sealant is applied and finished.
- We check our work before we leave.
Preparing for the visit
- Let us know about earlier repairs to the joints
- For business premises, tell us about site rules or sign-in
- Mention any tricky access
Get a quote
Want a quote for gutter sealing? Please call 0345 464 0079 or drop us an email and tell us about the job. We’ll explain what we’d do and give you a clear quote before work begins.
Related advice
Signs you need gutter sealing in St Johns
Stop ends take pressure from water running along the gutter. If the seal fails, water escapes at the end.
Common reasons people contact us are:
- Wet patches on the wall under a gutter joint
- Open joints in fascias and soffits
- Old gutter sealant that has let go
- Dripping gutter ends
Letting a property close to St Johns station? Then a gutter joint that drips onto the wall can turn into a damp complaint, so it’s worth checking.
Questions to ask before booking
- Whether they seal over old material or remove it
- What preparation is included
- What happens if the job turns out different
- What the cure time is
Should I try it myself first?
Some sealant jobs are within reach of a careful DIYer, like a short, easy-to-reach joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
Overfilling a joint is a classic DIY mistake. A heavy bead looks messy and copes badly with movement, and the joint depth matters as much as the finish.
What gutter sealing looks like in St Johns
Historic houses like Queen's House (about 1.1 miles north-east) are a reminder that the area around St Johns has older buildings as well as new. In older buildings, older brick and stone need a sealant that suits them, at the right joint depth. 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.
If you live in an older home near Church of St John, an extension built onto an older house moves differently, and the joint between them takes the strain. For site and facilities teams at buildings such as Ashmead Primary School, movement joints, cladding joints and gutters on larger buildings need the same care as a house’s.
St Johns is about 4 miles south-east of London, in Greater London. St Johns gets the same service as everywhere we cover: old sealant removed completely, careful preparation and a one-year guarantee. Our Greater London coverage runs to 764 places, and St Johns is one of them.
Work in SE13, SE10 and SE8 works the same way as everywhere else we cover. We cover properties on Avon Road, Mill Lane and Clare Road and the roads around them. With the A2210 and A2211 close by, St Johns is easy for our applicators to reach. Neighbouring places we cover for gutter sealing include New Cross (1 mile west), Deptford (1 mile north), Lewisham (1 mile south-east), Telegraph Hill (1 mile west) and Ladywell (1 mile south). Within a short drive, we also cover London (4 miles north-west), City of Westminster (6 miles north-west), Marylebone (6 miles north-west), Kensington (8 miles west), St Pancras (6 miles north-west) and Shoreditch (5 miles north-west).
Around St Johns
In St Johns, that means homes and buildings near Wickham Arms, Brookmill Park and Addey and Stanhope School. You’ll also find St. Paul's (0.7 miles north) and Laban Centre (0.8 miles north). There’s a railway station in St Johns itself: St Johns station. Nearby you’ll also find Fan Museum (0.9 miles north-east) and Lewisham Shopping Centre (0.7 miles south-east). The countryside around St Johns includes Brookmill Road Local Nature Reserve and Tower Hill.
What we cannot put right
We won’t take on work that won’t last, so these are the limits:
- Blocked downpipes
- Gutters that have dropped or pulled away
- A gutter length that has split
If you’re not sure, just call 0345 464 0079 or email us and we will give you a straight answer before you book.
Joints and surfaces we work on
- Roofline trims
- Soffit joints
- Gutter joints
- Garage door frames
- uPVC fascias
- Gutter end caps
St Johns questions
Is St Johns in your area for gutter sealing?
Yes. Our work covers London and the South East, and St Johns is part of that. Just call 0345 464 0079 or email us with a few details of the job.
Can parking be tricky for a visit in St Johns?
Parking in St Johns, 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.
Is it OK to seal over old sealant?
No, it will not last. It may look fine at first, but the new layer lifts away from the old one. Removing the old sealant completely is the only lasting way.
Can tenants book the work?
Yes. Ask your landlord first, and we can send them the quote if that helps.
Can you seal fascia and soffit joints?
Yes. We seal the joints, not replace the boards, and if a board is damaged, we will tell you.
How long will you be here?
As a guide, most jobs take a few hours, depending on the number of joints and the access. Larger jobs naturally take longer, and we will tell you how long to expect.
Can I do it myself?
You can, for simple jobs. Preparation is everything: all the old sealant out, and a clean, dry joint. If it does not work out, we can redo it.
Can I choose the sealant colour?
We help you choose a colour that suits, from white and clear to greys and other shades. The choice depends on the product the joint needs.
Landlords, agents and businesses in St Johns
Landlords and agents in St Johns can book us as well as householders. Sealant work between tenants keeps a property looking cared for.
We also work for property managers and facilities teams. We can quote a run of properties together.
Why deal with it now?
A dripping stop end can soak the wall right through the wet months. It’s a small job to put right before the damage spreads. 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 St Johns, the repair is bigger than the sealant job would have been.
The cost depends on how much there is to do, how hard the old material is to remove and how easy the joints are to reach. You will have a clear quote before any work starts, so you know where you stand.
Why choose Mr Mastic in St Johns
- A sealant colour to suit the surroundings
- We agree the colour with you first
- 180+ five-star Google reviews
- Neat joints and a tidy finish
See our cost guide and customer reviews.