Mastic sealing for building owners and managing agents in Portsmouth
Our CSCS-carded applicators take on mastic sealing for building owners, managing agents and housing associations in Portsmouth and the surrounding area. Send details for a fixed quote.
- Window mastic that has split and shrunk
- Damp patches beside frames
- Movement joints with sealant missing
Mastic sealing in Portsmouth
Tell us what needs sealing and where, with photos or drawings if you have them, and we’ll price it.
How we handle mastic sealing in Portsmouth
Different joints need different sealants. Window perimeters and external joints often take a low-modulus neutral-cure silicone, and MS polymer sealants stick well to many substrates and often take paint, and colours are confirmed for whichever product is used. We work on window and door perimeters on blocks, balcony and threshold joints and external wall and movement joints, and what we’re called in for most is failed external movement joints and damaged joints in communal entrances and corridors. Looking for mastic applicators who cover Portsmouth? We’ve been sealing commercial buildings since 2005, with CSCS-carded applicators.
In a large town like Portsmouth, landlords and agents with a portfolio usually have mastic of similar age across many buildings. One contractor, one programme and one fixed quote can cover the lot.
Work we carry out in Portsmouth comes with a 12-month guarantee. Should something we installed fail, give us a call on 01277 525 020 or email drawings and photos and we’ll come back to it.
- Where
- Portsmouth (PO6, PO4, PO1, PO2)
- Region
- Portsmouth
- Cover
- A 12-month guarantee
- Price
- Fixed quote, scope in writing
- Phone
- 01277 525 020
- Page updated
- 3 November 2026
Your questions answered
Do you cover business parks and estates near Portsmouth, such as Victory Retail Park?
Yes, sites like Victory Retail Park are within our area, along with the rest of Portsmouth. To start, just give us a call on 01277 525 020 or send photos by email with the unit, the joints involved and your access times.
Will you work in a care home in Portsmouth without moving residents out?
Yes. We agree rooms and times with the manager and work a few areas at a time. Any site rules, from signing in to infection control, are agreed before we start.
Do you supply RAMS and insurance details?
Let us know your requirements: tell us what site paperwork you need (RAMS, insurance certificate, CSCS details) and we’ll confirm with the quote. We hold CHAS accreditation and Constructionline membership.
Can you quote from photos?
It depends on the job. Simple work can often be priced from photos, while larger or less clear jobs get a site visit first.
Is it fine to apply new sealant on top of old?
No, never. Overlaying old sealant is a frequent cause of early failure, so it all comes out first.
Do you guarantee the mastic work?
A 12-month guarantee covers our work. It covers our workmanship, not later building movement, damage or frame failures.
Is Portsmouth in your area?
Yes. Portsmouth falls within our area, and the simplest way to start is to ring 01277 525 020 or send details through our quote form.
Also in Portsmouth
Diagnose, treat, sign off
On arrival, we sign in, go through any site induction and check how permits are handled. Floors, finishes and fittings next to the joints are covered before anything is cut or cleaned, and the work usually takes anything from a day to a few weeks, depending on the number of buildings and joints. In a large town like Portsmouth, work on busy buildings is planned area by area, keeping disruption low. Photos and drawings let us propose a sequence with the quote.
- A building-by-building inspection lists the failed joints.
- You get a fixed quote, per block or for the whole programme.
- Dates and areas are agreed so occupiers can be told.
- Old mastic is removed and the joint faces prepared.
- Joints are resealed and tooled.
- Each building is checked and signed off with the 12-month guarantee.
Preparing the site
- Make sure the joints can be reached
- Tell us what induction or permit system the site runs
- Point out parking and an unloading spot
Getting a fixed quote
The quickest route to a quote is a few photos and the site postcode. Upload them with the quote form, or ring 01277 525 020 or email drawings and photos if you’d rather talk the job through.
Related advice
When to bring in a specialist
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.
What you see is the finished bead, but most of the work is hidden. Backing rod, primer where specified and a joint designed to move with the building are where general trades tend to cut corners.
Why deal with it now?
Failed perimeter mastic lets cold air in around frames and the windows normally get the blame. In many cases, new perimeter sealant deals with it where the frames themselves are sound. If one joint has failed on your building in Portsmouth, others of the same age may be close behind. Dealing with them together saves repeat visits.
Access can matter as much as the joints themselves: joints within easy reach take less time than ones that need access equipment. Tell us how the joints are reached and call for a quote.
Why choose Mastic Doctor in Portsmouth
- Old sealant cut out, never sealed over
- A Constructionline member, so easy to vet
- One contact handling all your sites
- Workmanship guaranteed for 12 months
See what affects the cost or our accreditations and insurance.
Planned mastic for Portsmouth portfolios
Portsmouth is within about 1 mile of the coast. For owners and agents with buildings near the sea, exposed elevations are where frame mastic fails first, and they deserve more regular inspection. At about 64 miles from central London, Portsmouth is within reach of the capital. Within reach of London, blocks run by agents and associations are common around stations.
If your remit includes a building such as Manor Infant School, frame and door mastic can be programmed for the holidays. If you manage student housing near a university such as University of Portsmouth, 1.1 miles to the south of Portsmouth, the summer turnaround is the time for mastic. Landlords with units on estates such as Victory Retail Park (0.5 miles west of Portsmouth) can bring frame, door and external mastic across several units into one programme.
Portsmouth is in England. Any commercial site in Portsmouth is covered, whether it’s a single job or part of a planned programme. We work across 19 places in Portsmouth, from busy centres to rural villages.
Business premises anywhere in PO6, PO4, PO1 and PO2 are within our area. We cover commercial and managed buildings on Church Road, April Square and Rudmore Square and the roads nearby. Main routes into Portsmouth include the A3 and A27, useful when we plan access and materials. Sites close to Portsmouth are covered too, including Rudmore (1 mile north-west), Landport (1 mile south-west), North End (1 mile north), Fratton (1 mile south-east) and Kingston (1 mile south-east). Further afield, our area takes in Wymering (3 miles north), Paulsgrove (3 miles north), Drayton (3 miles north-east) and Farlington (3 miles north-east).
Landmarks near Portsmouth
Locally, jobs take us to sites close to The Portsmouth Academy, Alexandra Park and St Edmund's Catholic School. The nearest railway station is Fratton station, roughly 0.9 miles south of the centre. A little further out are Royal Portsmouth Hospital (0.7 miles south-west) and Charles Dickens Birthplace Museum (less than half a mile west). For a walk, there’s Milton Locks and Portsdown Hill.
After the work
For the best life from the joints:
- List the paperwork your organisation requires when you send details
- Reduce knocks to communal area joints
- Start inspections with the most exposed faces
- Avoid piecemeal callouts where you can
Protect entrance and corridor joints from knocks where possible. Damage at low level is the most common reason communal joints fail early.
Planned resealing is easier to budget than emergency repairs. We can quote buildings in priority order and work down the list.
When something else is needed
Being straight saves everyone time. Fresh joints won’t solve:
- Water coming in from the roof or rainwater goods
- Frames that are rotten, warped or broken
- Glazing that needs replacing
If in doubt, call 01277 525 020 or send details through our quote form and we will say what we think.
Surfaces we seal
- External wall and movement joints
- Communal kitchens and washrooms
- Communal entrances and stairwells
- Shopfronts below residential blocks
- Balcony and threshold joints
- Window and door perimeters on blocks
How the job changes by surface
External movement joints
The joint width has to suit the movement and the sealant’s capability with the width-to-depth ratio set as the manufacturer advises.
Estate-wide resealing programmes
Housing associations and agents often manage many similar blocks. We quote building by building and work through them in turn.