Cosham mastic sealing
Our CSCS-carded applicators take on mastic sealing for building owners, managing agents and housing associations in Cosham and the surrounding area. Send details for a fixed quote.
- Damaged joints in communal entrances and corridors
- Estate-wide sealant that is simply worn out
- Brittle perimeter mastic across a building
Mastic sealing for businesses in Cosham
Photos, a specification or a quick description of the joints is enough to start a fixed quote.
About our mastic sealing in Cosham
Owners and agents normally inherit a building’s mastic rather than choose it and it slowly wears out: it sits round windows and doors, along external joints and through communal areas. When it hardens, splits or pulls away, water and draughts follow along with complaints. We work on external wall and movement joints, window and door perimeters on blocks and shopfronts below residential blocks, and what we are called in for most is communal area joints that look neglected and water getting in round frames after rain. Searching for sealant specialists in Cosham? We’ve been sealing commercial buildings since 2005.
Places the size of Cosham normally have some housing association stock, small blocks and mixed-use buildings. Their window perimeters and external joints need renewing as the mastic ages.
Our workmanship is guaranteed for 12 months, in Cosham as everywhere else we work. If our installation lets you down in that time, we return and fix it.
- Place
- Cosham (PO6, PO3, PO2)
- Wider area
- Portsmouth
- Cover
- 12 months on every job
- Quotes
- Fixed quote, scope in writing
- Telephone
- 01277 525 020
- Updated
- 3 November 2026
Diagnose, treat, sign off
We bring the products specified for the job, along with primers and backing rod. Joint faces are cleaned back to sound, dry surfaces, primer goes on where the manufacturer specifies it, and the sealant is tooled off neatly. What matters most for a job in Cosham is a clear list of what needs doing, so send photos of each area. A fixed quote follows.
- First comes a look at the joints and, for older buildings, the asbestos records.
- A fixed quote covers the joints, products and order of work.
- Failed mastic is removed completely.
- The joints are prepared and resealed with the right product.
- We finish each building before moving to the next.
Before we start on site
- Send any specification or drawings in advance
- Send your site hours and access windows
- Send asbestos survey details if the building is pre-2000
Ask for a quote
A handful of photographs and a postcode is the fastest way to a quote. Upload them with the quote form, or ring 01277 525 020 or email the details over if you’d rather talk the job through.
Advice
Looking after the joints
To get the most from the new sealant:
- Mention RAMS, insurance or CSCS requirements up front
- Track which buildings were done and when
- Share the asbestos register when you send details
- Reduce knocks to communal area joints
Keep records of when each building was resealed. It helps plan the next round and shows what was done.
Joints on a building age together so a single failure is a sign to check the rest. A planned reseal saves repeated visits.
Honest limits
We seal joints; we don’t mend everything behind them. On its own, sealant can’t deal with:
- Substrate edges that need repairing first
- Leaks through the frame itself rather than the perimeter
- Materials that need asbestos testing before work
If you’re not sure, just speak to us on 01277 525 020 or email a schedule or drawings and we will give you a straight answer.
What we seal
- Communal kitchens and washrooms
- External wall and movement joints
- Window and door perimeters on blocks
- Balcony and threshold joints
- Communal entrances and stairwells
- Shopfronts below residential blocks
Places near Cosham
More services for Cosham
Your questions answered
Our building in Cosham is near the coast: does that change the sealant?
It can. Wind-driven rain and, closer to the shore, salt air are harder on external joints. Product choice and preparation matter more, and sea-facing elevations are worth inspecting more often.
Is Oak Park Industrial Estate, near Cosham, within your area?
Yes. We cover Cosham and the area around it, including industrial estates, business parks and retail parks such as Oak Park Industrial Estate. Photos and a short description are enough for a first look.
Can you plan resealing across several buildings?
Block-wide and estate programmes are common. You get a fixed quote per building or for the whole job.
Is Cosham in your area?
Yes. We cover Cosham, and the simplest way to start is to phone 01277 525 020 or email the details over.
When is resealing likely to be due?
It depends on movement, UV and weather, cleaning, traffic and the product. Sealant joints are maintenance items, so inspect them regularly.
How do you choose the sealant?
If the job is specified, we follow the specification. If not, we choose for the movement, the surfaces and the conditions, in line with the manufacturer’s guidance.
Can people stay in the building while you reseal?
Occupiers stay in the building throughout. If any flats or units need access, we’ll tell you in advance so it can be arranged.
Mastic sealing around Cosham: points for this area
Cosham sits close to the coast, within about 1 mile. On buildings near the shore, the side facing the weather usually needs its mastic renewed first. Cosham sits in one of the drier corners of the country, the South East. Outside work still depends on dry joints, and the sunniest, most exposed sides of a building usually need attention first.
If your remit includes a building such as Court Lane Junior Academy, frame and door mastic can be programmed for the holidays. Buildings close to stations like Cosham station, under half a mile south-west of Cosham, are often flats over shops, with frame mastic to keep sound. If you are responsible for a building such as Church of St Philip, frame and door mastic needs the same attention as any other property.
Cosham is about 2 miles south-west of Purbrook, in Portsmouth. Cosham sits inside our coverage and the rest of Portsmouth, and jobs here get the same fixed quote and 12-month guarantee as anywhere else. Across Portsmouth, 19 places are covered, Cosham among them.
We take on mastic joints across the PO6, PO3 and PO2 postcode area. Among the streets we cover are Dean Road, Park Lane and Elgin Road, and sites on any of them can send details for a fixed quote. You’ll find Cosham on or near the A397, so getting applicators and materials to site is simple. Nearby places we also cover include Wymering (1 mile north-west), Hilsea (1 mile south), Drayton (1 mile east), Widley (1 mile north-east) and Paulsgrove (1 mile west) for mastic joints. Further afield, our area takes in Southsea (4 miles south), Milton (3 miles south), Landport (3 miles south), Portsea (3 miles south-west), Portsmouth Point (4 miles south-west) and Fratton (3 miles south).
Local landmarks in Cosham
We work on buildings around The First Post pub, Alexandra Park and Springfield School and the streets around them. There’s a railway station in Cosham itself: Cosham station. A little further out are Tricorn Centre (2.9 miles south) and World War I Remembrance Centre (1 mile south-east). For a walk, there’s Southmoor Nature Reserve and Portsdown Hill.
Building owners, agents and FMs in Cosham
For main contractors, we work as the sealant subcontractor, on new build and refurbishment alike. We work to your programme, your specification and your site rules.
Agents, factors and owners’ representatives all follow the same route: send details, get a fixed quote, we seal, guaranteed. Keys, access and contacts can be agreed in advance.
Why act early in Cosham
Piecemeal repairs over the years often leave mismatched sealant. A block-wide reseal gives one product, one colour and one guarantee. In a smaller place such as Cosham, getting a contractor back for a second visit takes time, so we’d suggest renewing all the joints that are going, not just the worst.
Access often affects the price as much as the sealing: easy-to-reach joints are quicker than those that need equipment to get to. Mention the access as part of your enquiry.
Why us?
- A Constructionline member, so easy to vet
- Colour options checked against the specified product
- One phone line for London, the South East and Scotland
- CSCS-carded applicators
Read what affects the cost or our accreditations.
What the job involves on each surface
Communal areas
We keep entrances and stairs open throughout. Work is planned in sections.
Tenement and older buildings
Natural stone can be marked by the wrong sealant, so we pick a grade that won’t mark it.