Portchester mastic sealing
We carry out mastic sealing for building owners, managing agents and housing associations in Portchester and the surrounding area. Send details for a fixed quote.
- A mix of products and colours from past repairs
- Estate-wide sealant that is simply worn out
- Draughts at frames across a block
Mastic sealing in Portchester
Tell us what needs sealing and where, with photos or drawings if you have them, and we’ll price it.
Mastic sealing in Portchester, done properly
Different joints need different sealants. Low-modulus neutral-cure silicone suits many window perimeters and external movement joints, while hybrid polymer sealants grip many materials and are often paintable. We’ll confirm the colours available for the specified product. The enquiries we see most involve patchy repairs in mismatched sealant and leaks at window and door perimeters, on communal kitchens and washrooms, balcony and threshold joints and window and door perimeters on blocks. Most enquiries from Portchester start with one failed joint and grow into a wider look at the building: we look at the rest while we’re there and tell you what we find.
Converted and older buildings in and around Portchester often put modern windows into old walls. The mastic there needs to suit both surfaces.
Our workmanship is guaranteed for 12 months, in Portchester as everywhere else we work. If our installation lets you down in that time, we return and fix it.
- Where
- Portchester (PO16, PO6, PO17)
- Region
- Hampshire
- Guarantee
- A 12-month guarantee
- Price
- Quoted before any work starts
- Phone
- 01277 525 020
- Last updated
- 3 November 2026
Should maintenance staff do it?
Site maintenance staff can often handle a short internal joint. The usual problems come from preparation: sealing over old material, sealing onto damp or dusty surfaces, or a product that can’t take the movement.
There’s also the paperwork. Many sites expect CSCS cards, RAMS and proof of insurance, and we will confirm the paperwork you need with the quote.
Also near Portchester
Also in Portchester
Common problems we fix in Portchester
Frames, panels and masonry expand and contract through the year, and every joint has to stretch and squeeze with them. If the joint or the product wasn’t suited to the movement, it splits and fails early.
Clients normally get in touch after noticing one or more of the following:
- Damp patches beside frames
- Movement joints with sealant missing
- Communal area joints that look neglected
- Draught complaints from residents or tenants
Blocks of flats and mixed-use buildings often cluster around stations such as Portchester station (0.5 miles north-west of Portchester) and their window and balcony mastic tends to age at the same rate across a building.
Questions to ask before you book
- What the guarantee covers, and for how long
- What level of public liability insurance do they hold?
- Is the sealant right for the movement and the substrate?
- Will CSCS-carded applicators be on site?
Aftercare for building managers
Keep the joints in good shape with a few simple steps:
- Log resealing dates block by block
- Share your contractor requirements early
- Plan resealing building by building rather than complaint by complaint
- Keep bins and bikes away from communal door frames
Ask residents or tenants to report draughts or leaks round windows early. Early reports catch failures before damage spreads.
Failed mastic often goes unnoticed until heavy rain finds it. Resealing when cracking first shows avoids water damage and saves internal repairs.
For managing agents and facilities managers
Building owners and managing agents use us on everything from one building to a spread of sites. One quote can cover more than one site, which keeps the paperwork simple.
As a CHAS accredited contractor and Constructionline member, we make supplier vetting simple. Our insurance certificate can be sent along with the quote.
From enquiry to sign-off
Diagnose, treat, sign off: every visit follows that pattern. We inspect the joints and confirm what’s in scope, then the work is carried out to the specified product and detail, and the job ends with a walk round and sign-off. What matters most for a job in Portchester is a clear list of what needs doing, so send photographs of each area. You’ll then get a fixed price for the work.
- We inspect each building and record the joints that have failed.
- You get a fixed quote, per block or for the whole programme.
- Dates and areas are agreed so occupiers can be told.
- Failed sealant is removed and the faces prepared.
- New sealant goes in with backing rod and primer where needed.
- We check the finished work and confirm the guarantee.
Before we start on site
- Share your working hours and any access restrictions
- Tell staff and tenants when we’ll be in
- For older buildings, check the asbestos register before work
Request a quote
The quickest route to a quote is a few photographs and the site postcode. Send them through the quote form, or phone 01277 525 020 or email the details over if you’d rather talk the job through.
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FAQs: Portchester
Do you work for managing agents with blocks near Portchester station?
Yes, we work for agents, landlords and housing associations with blocks of every size. Photos of each elevation help us quote accurately.
Does the sea air around Portchester change the choice of sealant?
It can. Wind-driven rain and, closer to the shore, salt air are harder on external joints. We check the specified product suits the exposure and pay close attention to preparation.
Will residents or tenants be disturbed?
We plan around people living or working in the building. Dates and areas are agreed with you so residents or tenants can be told and communal access is kept open.
Does the weather affect the work?
For external joints, yes. The joint has to be dry and within the product’s temperature range, so frost, rain or cold mornings can delay outside work. Internal work is rarely affected.
Can you follow the specification on our project?
Yes. Include it with the drawings when you ask for a quote, and we’ll price the work to it, flagging anything that needs clarifying.
Do you guarantee the mastic work?
A 12-month guarantee covers our work. It applies to our workmanship rather than damage or problems with the frames.
How long before the joints can be used?
Curing time varies by product, and we confirm it on the day, and sign any area that should be left alone.
Frames, entrances and external joints in Portchester
Portchester sits close to the coast, within about 1 mile. Blocks and commercial buildings facing the sea take the most weather on their window perimeters and external joints. Central London is about 64 miles from Portchester. Managed blocks of flats are a big part of commuter-belt property, and window and balcony mastic on them tends to age at the same rate.
Schools and community buildings such as Castle Primary School need frame and external mastic kept sound like any building. Trustees of buildings like Church of St Mary can bring frame and external mastic into a planned maintenance list.
Portchester is about 3 miles north-east of Gosport, in Hampshire. Looking for mastic sealing in Portchester? We can help. Portchester is one of 723 places in Hampshire on our list.
If you need mastic sealing in PO16, PO6 and PO17, the process matches everywhere else we work: details, then a fixed price, then sealing and a 12-month guarantee. If your site is on Cow Lane, Hill Road and Ralph Road or close by, we can quote for mastic joints. Just outside Portchester, we also work in Boarhunt (2 miles north-west), Southwick (2 miles north), Elson (2 miles south-west), Wallington (2 miles west) and Priddy's Hard (2 miles south). Nearby towns on our patch include Gosport (3 miles south-west), Havant (6 miles east), Eastleigh (13 miles north-west), Fareham (3 miles west), Horndean (7 miles north-east) and Chandler's Ford (15 miles north-west).
Around Portchester
Recent enquiries here include premises near Portchester Community School and The Cormorant pub and the streets around them. For rail, the closest station is Portchester station, about 0.5 miles north-west. A little further out are Portchester Castle (under half a mile south-east) and Queen Alexandra Hospital (2.3 miles east). Open spaces near Portchester include West of the River Alver and Portsdown Hill.
Why deal with it now?
Leaving failed external joints lets water reach the structure behind. That can lead to damp, staining and damage to finishes and those cost far more to put right. Small buildings around Portchester suffer from failed joints as much as large ones. Early resealing avoids the damage that follows a leak.
The specified product makes a difference, and so does the preparation, from cutting out to priming and backing rod. Access, phasing and site requirements come into it too.
Why clients in Portchester choose us
- One phone line for London, the South East and Scotland
- CHAS accredited
- Matching to RAL references, product permitting
- Public liability insurance in place
Read what affects the cost and how we’re accredited.