Mastic sealing for building owners and managing agents in Northwood, Greater London
Mastic sealing in Northwood, backed by over 20 years in commercial sealing. Fully insured, with a 12-month guarantee.
- Draughts at frames across a block
- Patchy repairs in mismatched sealant
- Damaged joints in communal entrances and corridors
Mastic sealing across Northwood
Share the site address and what’s failing, and we’ll reply with a fixed quote or arrange a visit.
Common problems we fix in Northwood
Much failed sealant was laid on dirty, dusty or damp surfaces. Without clean, sound faces and a primer where the product needs one it comes away from one face.
Things that typically lead to an enquiry:
- Movement joints with sealant missing
- Water getting in round frames after rain
- No planned programme for sealant
- The same joint failures repeated across a portfolio
Older community buildings, Emmanuel Church among them, often have frames of mixed ages whose mastic varies.
What to look for in a quote
- Their public liability cover
- Health and safety accreditation such as CHAS
- How joint depth will be controlled
- How long is the guarantee, and what does it include?
Mastic sealing in Northwood
In buildings from before 2000, some old mastics contain asbestos. Before we disturb it, we ask to see the asbestos register or survey and if it’s suspected, work stops until it’s tested. We don’t remove asbestos-containing materials. If you are dealing with cracked, hardened mastic round windows on a block and mastic failing across several blocks on an estate, we can put it right. Facilities teams, main contractors and managing agents in Northwood tend to want the same three things: a fixed quote, no surprises on site and a 12-month guarantee behind the result.
London has a large stock of purpose-built blocks, mansion flats and converted buildings managed by agents and housing associations. Window and door perimeters, balcony joints and communal areas all have mastic that ages together across a building.
Whoever the client is, the cover is the same: twelve months on the work we carried out. Faults in the structure, damage and other trades’ work fall outside it, and we say so plainly.
- Location
- Northwood (HA6)
- Region
- Greater London
- Guarantee
- 12 months on our workmanship
- Quote
- Fixed quote, scope in writing
- Telephone
- 01277 525 020
- Last updated
- 3 November 2026
What happens if it’s left?
Dealing with failed joints one report at a time is slow and scattered. A planned programme treats each building once, under a single quote and a single programme. In a London building, a failed joint rarely affects only one party. Putting it right early is less disruptive than dealing with the consequences.
No two sites price the same: joint size, product, access and site hours all play a part. A fixed quote follows once we understand the job.
What you get with us
- One number for every site we cover
- Our applicators hold CSCS cards
- 12 months’ guarantee on every job
- Constructionline member
See our cost guide and our accreditations.
Different surfaces, different methods
Window and door perimeters on blocks
Window and door perimeters are where most mastic failure shows. We remove the failed mastic, prepare the faces, add backing rod if the joint is deep and reseal.
Estate-wide resealing programmes
Priority order can follow condition, complaints or your maintenance plan. Quotes can be per block or for the full programme.
Block-wide mastic in Northwood
Blocks in London are typically run by managing agents, landlords or housing associations, with residents to notify and access to arrange. We plan around the notices and access you arrange.
For agents with blocks near Carpenders Park station, which lies north-east of Northwood, a block-wide mastic programme deals with frames, balconies and entrances in one go. If your remit includes a building such as Frithwood Primary School, frame and door mastic can be programmed for the holidays.
Northwood is about 3 miles south-east of Rickmansworth, in Greater London. Our applicators travel to Northwood for work on mastic joints, handled exactly as we handle every other area. Across Greater London, 764 places are covered, Northwood among them. Our London page has more on work in that area.
Business premises anywhere in HA6 are within our area. Among the streets we cover are Little Stream Close and Sandy Lodge Way. Just outside Northwood, we also work in Eastbury (1 mile north-east), Moor Park (1 mile north-west), Batchworth Heath (1 mile west), Batchworth (2 miles north-west) and Holywell (2 miles north). Nearby towns on our patch include City of Westminster (14 miles south-east), Marylebone (14 miles south-east), Kensington (12 miles south-east), St Pancras (14 miles south-east), Hampstead (11 miles south-east) and Ruislip (3 miles south).
Local landmarks in Northwood
Around Northwood, our work takes us to commercial buildings near King George V Playing Fields, The Gate Public House and London School of Theology and the streets around them. Northwood’s nearest station is Carpenders Park station, about 1.7 miles north-east of the centre. Nearby you will also find Harlequin Centre (2.9 miles north-east) and Heath Robinson Museum (2.2 miles south-east). Not far away are Dews Farm Sand Pits and Tumbling Bay.
Common questions from Northwood clients
Will you take on work at estates like Wolsey Business Park, close to Northwood?
Yes, sites like Wolsey Business Park are within our area, along with the rest of Northwood. Photos and a short description are enough for a first look.
Do you work in London buildings with loading restrictions?
Yes, most London buildings have access rules of some kind, and we plan around them. Send the building rules and access times with your enquiry.
Do you guarantee the mastic work?
Every building we reseal has a 12-month guarantee. It applies to our workmanship rather than damage or problems with the frames.
Do you supply RAMS and insurance details?
Our credentials include CHAS, Constructionline and public liability insurance. For specific documents, tell us what site paperwork you need (RAMS, insurance certificate, CSCS details) and we will confirm with the quote.
Do you need to see the site first?
That depends on the size and complexity of the job. Straightforward work can often be priced from photographs and measurements, while larger or less clear jobs get a site visit first.
Will you quote for a small job?
We quote for single jobs as well as large packages and programmes. Send details for a fixed quote.
Who decides which product is used?
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.
Maintenance after handover
To get the most from the new sealant:
- Look at the sunniest and most exposed elevations first
- Keep bins and bikes away from communal door frames
- Share your contractor requirements early
- Include mastic in your cyclical inspections
Keep bins, bikes and deliveries away from low-level joints where you can. 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.
Honest limits
Not every problem is a sealant problem, and we’re upfront when that’s the case. It won’t fix:
- Cracked or crumbling render, brick or stone at the joint edges (we will tell you if so)
- Broken glass or failed sealed units
- Failed window or door frames, which need a window contractor
Not sure which it is? You can call 01277 525 020 or email the details over and we will tell you honestly before you book.
Surfaces we seal
- Window and door perimeters on blocks
- Communal kitchens and washrooms
- External wall and movement joints
- Shopfronts below residential blocks
- Communal entrances and stairwells
- Balcony and threshold joints
Places near Northwood
More services for Northwood
How a job runs
Diagnose, treat, sign off: that’s the shape of every visit. We inspect the joints and confirm what’s in scope, then we prepare and seal each joint with the specified product, and the job ends with a walk round and sign-off. All of Greater London is in the ULEZ, and kerbside space in Northwood can be scarce. If there’s a loading bay, a car park or a permit we can use, tell us when you send details.
- Each block or building is walked and the failed joints recorded with the likely cause.
- We send a fixed quote that sets out the joints, the products and the programme.
- The programme is fixed with you, including dates you can pass on to residents or tenants.
- Old sealant is stripped and each face prepared back to firm material.
- Backing rod and primer go in as the joint requires, then the new bead is placed and tooled.
- Completed joints are inspected and carry a 12-month workmanship guarantee.
Preparing the site
- Let building users know which areas are affected
- Arrange parking or a loading space
- Tell us what induction or permit system the site runs
Quotes
A handful of photographs and a postcode is the fastest way to a quote. Upload them with the quote form, or call the office on 01277 525 020 or email a schedule or drawings if you’d rather talk the job through.