West Sussex · England
Portfield Window Mastic
Problem with your window and door frames in Portfield? We remove the old material, prepare the joints and seal them properly.
- Gaps where the sill meets the wall
- Sealant in the wrong colour for the frame
- Rushed sealant from a window installation
Window mastic for homes and businesses in Portfield
Every window and door frame has a gap around it, and mastic is what closes it. When it cracks, hardens or pulls away, draughts and rain get in. Our applicators cut it out and replace it with a flexible, weatherproof sealant. We work on uPVC windows, aluminium frames and patio & French doors, and the jobs we see most are leaking joints at the ends of sills and damp patches on the reveal after heavy rain.
In a smaller place like Portfield, some walls face open ground and catch the full force of the weather, so exposed windows and doors face the weather head on. The mastic around frames on those walls tends to age faster.
Whatever the size of the job, you get the same one-year guarantee.
- Place
- Portfield (PO19, PO20, PO18)
- Wider area
- West Sussex
- Guarantee
- A year, on every job
- Quotes
- A clear price before we start
- Phone
- 0345 464 0079
- Updated
- 26 October 2026
DIY sealant or a professional job?
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. All the old material has to come out first.
Some jobs are best left to a professional: work at height, external movement joints, fire-rated sealant and large areas need the right product, the right access and the right method.
Towns and villages near Portfield
More services for Portfield
Why it’s worth doing now in Portfield
Once mastic fails, rain can get between the frame and the wall. Over time that can mean damp patches, damaged plaster and rotting timber. A reseal is a much smaller job. Homes in smaller places like Portfield can face more weather, and failed outside joints let damp into walls. Indoors, a failed seal lets water into floors and panels as it would anywhere.
No two jobs are quite the same, so we quote each one individually. The number of joints, how easy they are to reach and the sealant needed all play a part.
Why choose Mr Mastic in Portfield
- ARBOMaster approved applicator
- A 12-month guarantee on all work
- 20+ years of sealant experience
- Trusted Arbo and Everbuild sealants
Take a look at what affects the cost or customer reviews.
Common questions in Portfield
I let a flat near Chichester station. Can you help?
Yes, rental work is part of what we do. You can phone 0345 464 0079 or email us with the address and a few details, and we will give you a fixed price before we start.
Can you do window mastic in Portfield?
Yes. We work across London and the South East, and Portfield is part of that. Just ring 0345 464 0079 or email us with a few details of the job.
How long should I leave it?
Different products cure at different speeds, so follow the cure time we give you when we finish.
Can you do several jobs on one visit?
Yes. More than one area can go on one quote.
Do you take out the old sealant first?
Yes, always, and completely. New sealant won’t bond properly to old, so the joint is cleaned back first.
Will you leave a mess?
Tidy work is part of the job. We protect what’s around the joints, and the area is left clean when we finish.
Do the sealants smell?
It depends on the product. Some smell for a while, some hardly at all.
What do you put in the joint?
Products from Arbo and Everbuild, among others, picked for each joint. We explain the product when we quote.
How to look after the new joints
So the new joints stay in good condition:
- Ventilate rooms so frames do not stay wet inside
- Keep jet washers away from the mastic
- Keep paint and stain on wooden frames in good order
- Make sure the drainage slots are not blocked
Silicone cannot generally be painted, so if you are planning to paint the frames or walls, tell us beforehand. There are paintable sealants for joints that need it.
Signs to watch for: cracks in the mastic, gaps you can see light through, damp on the reveal or mould around the inside of the frame. Any of these is worth a call.
What we can’t put right
Before booking, it’s worth knowing the limits too:
- Condensation trapped between the panes
- Worn gaskets, brush seals or a door that has dropped
- Rotten timber, which needs a joiner first
Not sure which it is? You can ring 0345 464 0079 or email us and we’ll tell you honestly.
Where we work in Portfield
- Window sills
- uPVC windows
- Patio & French doors
- Aluminium frames
- Composite doors
- Timber windows & doors
How we quote for window mastic
You’ll get a clear quote before we start. It’s based on:
- The size of the job
- Access and height
- The number of rooms or windows
- How much old sealant there is and how hard it is to remove
What you pay reflects the work, not guesswork. That’s why we ask a few questions first and agree the price before starting.
What to tell us for a quote
Photos by email are helpful but not essential. Try to tell us:
- What the problem is, such as mould, gaps, leaks or cracking
- Roughly how big the job is
- A few photos by email, if you can
- Whether it’s a home or a business
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 drop us an email.
Windows and doors in Portfield
Compared with the north and west, the South East gets less rain, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day. Historic houses like Goodwood House (about 2.5 miles north) are a reminder that the area around Portfield has older buildings as well as new. In older buildings, older frames set in brick or stone need a sealant that suits them, and sometimes that’s traditional sand mastic.
For an older house near a landmark such as St George's, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint. If you look after a building such as Portfield Primary Academy, its window and door frames need their mastic kept sound, just like a home’s. Rented homes near Chichester station change hands often, and sound mastic around windows and doors keeps out the draughts and damp that tenants notice first.
Portfield is about 1 mile east of Chichester, in West Sussex. Jobs in Portfield get the same care as everywhere else we work: old sealant removed completely, careful preparation and a one-year guarantee. Our West Sussex coverage runs to 371 places, Portfield among them. There’s also a page for Portsmouth, roughly 14 miles from Portfield.
Work in PO19, PO20 and PO18 works the same way as everywhere else we cover. Whether your property is on Kent Road, York Road and Spur Road or anywhere close by, our applicators can take on the job. Portfield is on the A259 and A285, so it’s easy for us to get to with everything needed for window mastic. Nearby, we also carry out window mastic in Chichester (1 mile west), Westhampnett (1 mile north-east), Shopwyke (1 mile east), Maudlin (1 mile north-east) and North Mundham (2 miles south). Larger places within reach include Bognor Regis (5 miles south-east), Selsey (7 miles south), Littlehampton (10 miles east), Emsworth (8 miles west), Rustington (11 miles east) and Storrington (15 miles north-east).
Around Portfield
In Portfield, that means homes and buildings near The Prebendal School, The East Gate Public House and Chichester High School For Girls. For rail, the closest station is Chichester station, roughly 0.9 miles west. Other landmarks nearby include The Chichester City Museum (0.6 miles west) and Chichester Castle (0.6 miles west). Open spaces near Portfield include Kingley Vale National Nature Reserve and Stoke Down.
What we do, step by step
Good joint work is mostly preparation, and we don’t rush it. Every joint is cleaned and dried before new material goes in. All told, the work takes anything from an hour or two to a full day, depending on how many frames there are. For a job in Portfield, we agree the time, the access and parking before the day. If the work is outside, the weather plays a part, as sealant needs a dry surface.
- 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.
- A flexible exterior sealant is applied in a colour to suit the frame.
- We tool each bead neatly and check every joint is closed.
Before we arrive
- Tell us about any previous sealing or DIY attempts
- For indoor joints, keep the area dry beforehand if you can
- Mention any leaks or damp you’ve noticed
How to get a quote
For a quick quote, get us on the phone, or send an email if you’d rather. Tell us about the joints that need doing and we’ll explain what’s involved and give you a clear quote.
Advice
Surface by surface
Aluminium frames
Aluminium needs a sealant that bonds to coated metal, and acetoxy silicones are not used, as they can attack some metals. Neutral-cure sealant is the safe choice.
Composite doors
An exposed front door gets wind-driven rain. Those corners get the most care.