West Sussex · England
Sand mastic for sash & case windows in Portslade, West Sussex
Sand mastic in Portslade from a team with over 20 years’ experience. 180+ five-star Google reviews and a 4.9 rating.
- Silicone on a period window that looks wrong
- Failed mastic on an exposed elevation
- Gaps round a timber door in stone or brick
Windows and doors 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. That is hard on the mastic around older windows and doors, especially on the side facing the sea. London and the South East are among the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
Managing a site like Peter Gladwin Primary School? Then its window and door frames need their mastic kept sound, just like a home’s. Homes close to St Nicolas Church include some older properties, and the windows may be timber, sash or later replacements, and each needs the right sealant against the wall.
Portslade is about 1 mile west of Brighton and Hove, in West Sussex. Portslade gets the same service as everywhere we cover: the old material taken out, joints prepared properly and a 12-month guarantee. Across West Sussex, we cover 371 places, and Portslade is one of them.
Postcode districts we cover here for sand mastic: BN41, BN3 and BN42. If you need sand mastic at a property on Mill Lane, Crown Road and Drove Road or anywhere close by, our applicators can take on the job. With the A293 close by, Portslade is simple for us to get to for sand mastic. We also cover 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). Further out, we also cover 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).
Local landmarks in Portslade
Typical jobs here are in homes near King's School, Benfield Hill and The Mill House. For rail, the closest station is Fishersgate station, about 0.7 miles south. Well-known places in the area include British Engineerium (1.8 miles east) and Southlands Hospital (1.8 miles west). Green spaces nearby include Shoreham Beach and Thundersbarrow Hill.
Sand mastic in Portslade
Old sand mastic cracks, crumbles and falls out over time, leaving gaps round the window. Renewing it closes the gap and tidies the surround. Common call-outs are for window mastic to renew ahead of painting and gaps round a timber door in stone or brick, on period & listed homes, stone surrounds and tenement windows.
In smaller places like Portslade, homes range from older cottages to newer houses, with windows to match: timber, uPVC and aluminium. The right sealant depends on the frame and on what it sits in.
Whatever the size of the job, you get the same 12-month guarantee.
- Location
- Portslade (BN41, BN3, BN42)
- Region
- West Sussex
- Cover
- 12 months on all our work
- Price
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
Places near Portslade
What else we do in Portslade
Aftercare tips
Simple care keeps the joints in good condition. We recommend:
- Plan mastic work ahead of painting
- Keep sills and gutters clear so water drains away
- Go gently near the mastic when preparing windows
- Have rotten timber repaired before new mastic goes in
Don’t run silicone over the new mastic. If you see a crack, ask us to take a look rather than patching it.
It’s best to renew mastic before painting the windows. Paint over cracked mastic only covers it up.
For landlords and businesses
We work for letting agents and landlords as well as homeowners. Resealing between tenancies is a simple way to keep a property in good order before the next move-in.
Mouldy or split sealant often shows up at the end of a tenancy, and it’s quick to put right between tenancies. We can quote for more than one property at once.
What we do, step by step
A visit follows a simple pattern: we look at the joints together, protect the area around them, do the work and tidy away. Most jobs take a few hours for a single window, longer for several. For a job in Portslade, we agree the time, the access and parking before the day. Outdoor jobs depend on a dry day, since sealant needs a dry surface.
- We check each window surround and the condition of the joint.
- The joint is raked out and cleaned.
- We fill deep gaps so the new mastic isn’t too thick.
- New sand mastic is applied and shaped by hand.
- The finish is dressed neatly.
Before we arrive
- Tell us about any previous sealing or DIY attempts
- On commercial sites, let us know about site rules
- Let us know about parking restrictions
How to get a quote
A good description makes for an accurate quote. Let us know the location, the problem and roughly how many joints, and add photos by email if you can.
Read more
Portslade questions
Can you help a landlord with a rental near Fishersgate station?
Yes. We work for landlords and agents as well as homeowners, and several properties can be quoted together. You can call 0345 464 0079 or email us with the details for a clear quote.
Will you come out to Portslade?
Yes, smaller places are covered as well as towns. We work across London and the South East. Just mention lanes, gates or anything else about the route when you book.
Do you do commercial work?
Yes, regularly. Larger jobs can be planned room by room or area by area.
Will the old sealant be removed?
Yes. Sealing over the old bead is the commonest cause of early failure, so we never do it.
Will it make a mess?
We keep the work tidy. We protect what’s around the joints, and we clear up when we’re done.
How long will you be here?
Most jobs take anything from a few hours to a full day, depending on how many windows. Your quote will say how long we expect yours to take.
Do I have to be there?
We need access to the joints, so we’ll agree that with you when we book. Indoors, that generally means someone at home.
Which products do you use?
Products from Arbo and Everbuild, among others, picked for each joint. We explain the product when we quote.
Should I try it myself first?
If you’re set on DIY, put the effort into preparation: remove every trace of old sealant, clean and dry the joint, and follow the product’s cure time. If it fails, we can still redo it.
Too much sealant is as bad as too little. A thick, smeared bead looks untidy and doesn’t move well, and the joint depth matters as much as the finish.
How we quote for sand mastic
The price is agreed before any work begins. It’s based on:
- The type of sealant required
- The number and length of the joints
- Mould in or behind the old joints
- The number of rooms or windows
What it costs depends on the size of the job, how hard the old material is to remove and access to the work. You will have a clear quote before any work starts.
What we need to know
There’s no need for technical detail. Just tell us:
- Whether it has been sealed before
- What’s wrong with the joints now
- Photos by email, if that is easy
- The type of property
Asking for a quote is easy: let us know the job and the location. A few photos by email make the job easier to understand.
How the job changes by surface
Timber door frames
Door frames get knocked and soaked, so their mastic can fail sooner. We rake it out and renew it.
Period and listed homes
Many older homes were built with sand mastic round the windows. On listed buildings, check with your planning authority first.
Common problems we fix in Portslade
Some old mastic was never deep enough. Mastic that’s too thin cracks and drops out so we make sure the new mastic is the right thickness.
People usually contact us when they notice one of these:
- Window mastic to renew ahead of painting
- Silicone on a period window that looks wrong
- Mastic worn away on windows facing the weather
- Gaps where the frame meets the masonry
Letting a property close to Fishersgate station? Then cracked sand mastic around sash windows lets in the draughts tenants complain about.
Questions to ask before booking
- Is the old sealant removed completely?
- How hidden problems are handled
- How the colour is chosen
- Who turns up on the day