Mastic sealing for building owners and managing agents in Greenhill, Greater London
Planning work on a mastic joint in Greenhill? We assess it, carry out the work and guarantee our workmanship for 12 months.
- Brittle perimeter mastic across a building
- Damp patches beside frames
- Mastic failing across several blocks on an estate
Need mastic sealing in Greenhill?
Tell us what needs sealing and where, with photos or drawings if you have them, and we’ll price it.
What we are called out for in Greenhill
UV and rain age external sealant. The surface chalks, the body stiffens and cracks appear, especially on south and west faces.
Look out for the following:
- Open joints in brickwork or panels
- Patchy repairs in mismatched sealant
- Draughts at frames across a block
- Estate-wide sealant that is simply worn out
Schools and community buildings such as The Royal School need frame and external mastic kept sound like any building.
What your quote should include
- Is depth set with backing rod, or bond-breaker tape in shallow joints?
- Will RAMS and insurance details be available?
- What the guarantee covers, and for how long
- Who will actually carry out the work
Mastic sealing in Greenhill, done properly
Managing agents and housing associations usually need paperwork before anyone starts. For documents, tell us what site paperwork you need (RAMS, insurance certificate, CSCS details) and we will confirm with the quote. We are CHAS accredited and a Constructionline member, with public liability insurance. The enquiries we see most involve cracked, hardened mastic round windows on a block and occupiers reporting cold air round windows, on communal entrances and stairwells, window and door perimeters on blocks and communal kitchens and washrooms. A specialist sealant contractor works differently from a general builder: on jobs in Greenhill, preparation and product choice get the time they need.
Across Greater London, Greenhill included, the ULEZ applies, and parking and loading rules differ from street to street. For block-wide work, a place to park and store materials saves time on every visit.
Building owners and contractors get the same cover: a 12-month guarantee on our workmanship. It doesn’t extend to damage, faults in the building or work by others, and we’re upfront about that.
- Place
- Greenhill (NW3, NW6)
- Region
- Greater London
- Cover
- 12 months on every job
- Quote
- Fixed quote, scope in writing
- Phone
- 01277 525 020
- Last updated
- 3 November 2026
Planned mastic for Greenhill portfolios
London blocks come with residents to inform, access to agree and often a concierge or estate office to work with. Our programme follows the access you agree with residents. The 2 miles around Greenhill include five care or nursing homes. For owners and operators of care buildings, window perimeters and external joints are best renewed in planned phases around residents.
Trustees of buildings like Rosslyn Hill Unitarian Chapel can bring frame and external mastic into a planned maintenance list. If you own or manage units on a site such as Regis Road Business Park, 1.3 miles east of Greenhill, failed mastic on frames, door surrounds and external joints can be dealt with unit by unit.
Greenhill is about 1 mile north-east of Hampstead, in Greater London. We send applicators to Greenhill for mastic joints, handled exactly as we handle every other area. Across Greater London, 764 places are covered, Greenhill among them.
Postcode districts covered here: NW3 and NW6. Buildings on Back Lane, Well Road and Ornan Road are within our area for mastic joints. Just outside Greenhill, we also work in Hampstead (1 mile south-west), Vale of Health (1 mile north), West Hampstead (1 mile west), Fortune Green (1 mile west) and Haverstock (1 mile south-east). Further afield, our area takes in London (5 miles south-east), City of Westminster (3 miles south), Marylebone (3 miles south-east), Kensington (4 miles south), St Pancras (3 miles south-east) and Shoreditch (5 miles south-east).
Around Greenhill
In Greenhill, that means premises near Cecil Sharp House, Fitzjohn's Primary School and King William IV Public House. Also close by are South Hampstead High School (0.6 miles south) and Hampstead Heath (0.7 miles north-east). Greenhill has its own railway station: Hampstead Heath station. Other landmarks nearby include New End Hospital (under half a mile north-west) and Montfichet's Tower (4.3 miles south-east). Green spaces nearby include Belsize Wood and Parliament Hill.
Towns and villages near Greenhill
Other services in Greenhill
What the job involves on each surface
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
Consistent products and colours across an estate make future maintenance simpler and easier to manage.
Why act early in Greenhill
Looking at mastic during planned maintenance costs little. Waiting until leaks appear means working under pressure with less control over timing. 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: the joint sizes, the specified product, access and working hours each have a bearing. A fixed quote follows once we understand the job.
Why choose Mastic Doctor in Greenhill
- One number for every site we cover
- Colour agreed before work starts
- Public liability insurance in place
- CSCS-carded applicators
Take a look at how commercial sealant jobs are priced and our accreditations.
From enquiry to sign-off
Before any cutting starts, the area is protected: masking tape along the joint edges and sheeting over anything nearby. On site, the work typically takes a day or two for a single block, longer for an estate programme, and our waste is bagged and taken away as we go. The ULEZ covers the whole of Greater London, and parking near a job is rarely simple. Let us know about any on-site parking or loading arrangements when you send the job details.
- 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.
- Joints are resealed and tooled.
- Each building is checked and signed off with the 12-month guarantee.
What we need from you
- Warn occupants and staff about the work
- Let us know about inductions and permits
- Tell us which areas need to stay in use
Get a fixed quote
Photos, drawings or a schedule of the joints and a fixed quote comes back to you. If the job needs a look first, we will arrange a site visit.
Advice
When something else is needed
Not every problem is a sealant problem, and we are upfront when that’s the case. It won’t fix:
- Substrate edges that need repairing first
- Asbestos-containing sealant, which we don’t remove
- Misted or failed double-glazed units
If you’re not sure, just give us a call on 01277 525 020 or email a schedule or drawings and we’ll give you a straight answer before you book.
What we seal
- Balcony and threshold joints
- Communal kitchens and washrooms
- Communal entrances and stairwells
- Window and door perimeters on blocks
- Shopfronts below residential blocks
- External wall and movement joints
Cost factors for mastic joints
We price every job individually. The main factors are:
- Location, for remote and island sites
- The product specified
- Backing rod, priming and other preparation
- Working within restricted access windows
Cost follows what’s involved: removing old material, preparing the joints, the product, the access and how the work is phased. Call for a quote.
Before you send an enquiry
A good diagnosis starts with the right details. Tell us:
- Any dates the work must fit around
- Approximate linear metres or a joint schedule
- Access details, including height
- The site address and postcode
Quotes are fixed against the scope you send, so the cost is agreed before work starts. To start the process, give us a call on 01277 525 020 or email a schedule or drawings.
Common questions from Greenhill clients
Can you work at a site such as Regis Road Business Park, by Greenhill?
Yes, sites like Regis Road Business Park are within our area, along with the rest of Greenhill. Photos and a short description are enough for a first look.
Can you work in a London building with booked loading and goods-lift slots?
Yes, most London buildings have access rules of some kind, and we plan around them. The building manager’s rules go straight into our method.
Will you come and look before quoting?
Photos, drawings or a schedule are often enough to quote. If the job needs a look first, we’ll arrange a visit before quoting.
Can you take on resealing for a block portfolio?
Yes, that’s exactly who this service is for. We work through buildings in a planned order so you can plan around it.
Can weather delay the job?
Outside, yes. Sealant needs a dry joint and a temperature within the product’s range, so damp, frosty or very cold days can stop external work. Inside work is seldom held up.
What about access for upper-floor joints?
It depends on the building. We agree access with you at quote stage so there are no surprises.
Do you do block-wide mastic programmes?
Yes. We survey and price each building, then work through them in order starting wherever is most urgent.