West Sussex · England
Window & door mastic in Portslade, West Sussex
Problem with your window and door frames in Portslade? We remove the old material, prepare the joints and seal them properly.
- Rushed sealant from a window installation
- Mastic that has split away from the wall
- Water coming in at the bottom corners of a door
Window mastic in Portslade
A cold draught around a closed window often comes from the frame edge. A new joint stops the air getting through. If the draught is through the window seals instead, we’ll tell you. We work on timber windows & doors, uPVC windows and patio & French doors, and the jobs we see most are mastic that’s falling out in pieces and draughts coming in around windows and doors.
Around Portslade, conservatories, garden rooms and patio doors are often part of the house. Their glazing joints and frame seals are as much a part of the job as the windows, and any older timber or sash windows need a sealant that suits them.
We stand behind the work with a 12-month guarantee.
- Place
- Portslade (BN41, BN3, BN42)
- Wider area
- West Sussex
- Cover
- One year on every job
- Quotes
- Quoted before any work starts
- Call
- 0345 464 0079
- Updated
- 26 October 2026
Different surfaces, different methods
uPVC windows
Plastic frames move a lot between a hot afternoon and a cold night, so we use a flexible, low-modulus sealant. We match white, brown, anthracite grey and black frames.
Composite doors
If the door itself is draughty, the issue may be the door seals or hinges rather than the frame mastic. We seal the frame and let you know about anything else.
What window mastic looks like in Portslade
Portslade is close to the coast, and homes near the sea take more wind-driven rain, with salt in the air closer to the shore. Both are hard on the mastic around window and door frames, which can dry out and crack sooner where a building faces the weather. Historic houses like Portslade Manor (about 0.1 miles south-west) are a reminder that the area around Portslade 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.
Managing a site like Peter Gladwin Primary School? Then the mastic around its windows and doors needs looking after like any other building’s. Letting a property close to Fishersgate station? Then cracked frame mastic tends to show up as a draught or damp complaint, so it’s worth checking between lets.
Portslade is about 1 mile west of Brighton and Hove, in West Sussex. From the centre of Portslade to the outskirts, we cover window mastic for every kind of property. Portslade is one of 371 towns and villages in West Sussex where we work for window mastic.
All of BN41, BN3 and BN42 is covered for window mastic, from the main roads to the quietest streets. You’ll find streets such as Mill Lane, Crown Road and Drove Road. Portslade sits on or near the A293, which makes travel easy. Nearby, we also carry out window mastic in Hangleton (1 mile north-east), Southwick (1 mile south-west), Kingston by Sea (1 mile west), Shoreham-by-Sea (2 miles west) and Old Shoreham (3 miles west). We also work in nearby towns such as Worthing (8 miles west), Haywards Heath (12 miles north-east), Burgess Hill (9 miles north-east), Littlehampton (14 miles west), Lancing (5 miles west) and Rustington (13 miles west).
What’s near Portslade
Locally, jobs take us to homes and businesses close to King's School, Benfield Hill and The Mill House. The nearest railway station is Fishersgate station, roughly 0.7 miles south of the centre. Well-known places in the area include British Engineerium (1.8 miles east) and Southlands Hospital (1.8 miles west). Not far away are Shoreham Beach and Thundersbarrow Hill.
Also near Portslade
What else we do in Portslade
What we’re called out for in Portslade
Frames are never completely still. A plastic or aluminium frame lengthens in sunshine and shortens as it cools, while the brick or render around it hardly moves. A sealant that cannot keep up eventually tears.
The problems people usually mention when they call are:
- Cracked sealant at the sill ends
- Cracked internal joints between frame and plaster
- Cold air getting in at the frame edge
- A bead that doesn’t match the frame
In the older streets around St Nicolas Church, the windows may be timber, sash or later replacements, and each needs the right sealant against the wall.
Comparing quotes
- How hidden problems are handled
- Is the old sealant removed completely?
- What insurance they hold
- Which sealant they’ll use, and why
Looking after it afterwards
How long the joints last depends on use and care. Here’s what we suggest:
- Check the mastic once a year
- Wipe condensation off the frames
- Avoid blasting the frames with a pressure washer
- Keep drainage slots and sill grooves clear
Most silicone sealants won’t take paint, so if you are planning to paint the frames or walls, tell us beforehand. We can use a paintable sealant where that matters.
Signs to watch for: split or missing mastic, gaps, damp patches inside or black mould on the reveal. Any of these is worth a call.
What happens on the day
On the day, there’s very little for you to do. Show us the job and we’ll take it from there. The job generally takes most of a day for a typical house, less for a few frames, including the tidy-up. In a smaller place like Portslade, parking is seldom the issue; lanes, gates and long drives are worth mentioning. If the job is outside, tell us about side access and how high the joints are.
- Each frame is looked over and we agree which ones need resealing.
- We remove the old mastic and clean the frame edge and wall.
- Where the gap is deep, backing rod goes in first.
- The new sealant goes on in white, brown, anthracite grey, black or clear to suit.
- We tool each bead neatly and check every joint is closed.
How to prepare
- Plan for the work area to be out of bounds to pets and children
- For business premises, tell us about site rules or sign-in
- Let us know about parking restrictions
Get a quote
The more we know about the job, the more useful the quote. Let us know the location, the problem and roughly how many joints, and add pictures by email if you can.
Advice
Honest limits
Some problems need a builder, plumber or other trade rather than us:
- Faulty window hardware
- Soft or decayed wood in the frame
- Damp coming through the wall itself rather than the frame joint
Not sure which it is? You can phone 0345 464 0079 or drop us an email and we will tell you honestly.
What we seal
- Timber windows & doors
- Composite doors
- Window sills
- Aluminium frames
- uPVC windows
- Patio & French doors
Your questions about window mastic in Portslade
Can you help a landlord with a rental near Fishersgate station?
Yes. We work for landlords and letting agents as well as homeowners, and several properties can go on one quote. You can call 0345 464 0079 or drop us an email with the details for a clear quote.
Does the coastal weather in Portslade affect outside sealant?
Coastal homes put outside sealant through more weather than inland ones, so preparation and the right sealant matter all the more. Walls facing the sea are normally the first to need attention.
What information do you need?
Tell us what needs doing and where, plus pictures if you have them. If we need more, we will ask.
What does window mastic cost?
There’s no set price, as it depends on the job: its size, the old material, access and the product needed. We agree the price before any work begins.
Where are you based?
We are a Crawley-based firm. We work across South East England, London and Scotland.
How long does it take to reseal the windows on a house?
That depends on the number of frames, how they’re reached and the state of the old mastic. You will know the timing when we quote.
Can I do it myself?
That depends on the joint. High-level, external movement and fire-rated joints are professional jobs, while a short indoor joint may be within reach.
Do you hold any approvals?
Yes. We’re an ARBOMaster approved applicator, the approved applicator scheme for Arbo sealants.
How we quote for window mastic
We quote each job individually. This is what makes a difference:
- Which sealant suits the joint
- How many areas need sealing
- The number and length of the joints
- When we can work, for business premises
Instead of a standard rate, we look at what your job involves: how many joints, what’s in them now and how we reach them. You will know the price before we begin.
Helping us quote
To make quoting easier, let us know:
- A few pictures by email, if you can
- Whether it’s a home or a business
- Any previous sealing or DIY work
- Where the job is, and your postcode
There’s no standard price list. Instead, your job gets its own clear quote. To get started, phone 0345 464 0079 or send us an email.
Can I do it myself?
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.
Overfilling a joint is a classic DIY mistake. A heavy bead looks messy and copes badly with movement, and getting the depth right matters as much as the look.