Broad Colney mastic sealing
Mastic sealing for building owners, managing agents and housing associations in Broad Colney and across Hertfordshire. CHAS accredited, Constructionline member, with a 12-month guarantee on workmanship.
- Patchy repairs in mismatched sealant
- Leaks at window and door perimeters
- Damaged joints in communal entrances and corridors
Mastic sealing across Broad Colney
Tell us what needs sealing and where, with photos or drawings if you have them, and we’ll price it.
About our mastic sealing in Broad Colney
In buildings from before 2000, some old mastics contain asbestos. Before we disturb it, we ask to see the asbestos register or survey, and work stops for testing if there’s any doubt. We don’t remove asbestos-containing materials. We work on balcony and threshold joints, communal entrances and stairwells and external wall and movement joints, and the failures we’re asked to look at most are complaints coming in block by block and patchy repairs in mismatched sealant. Whoever orders the work in Broad Colney, the brief is normally the same: a clear scope, tidy work and joints that don’t fail again.
In and around smaller places like Broad Colney, landlords and agents often look after small groups of housing association properties, converted farm buildings and community buildings. Mastic around frames and on external joints wears out in time, whatever the building.
Guaranteed is the last step of every job. Our workmanship is backed for 12 months, and the quote explains what it covers.
- Place
- Broad Colney (AL2)
- Region
- Hertfordshire
- Cover
- A 12-month guarantee
- Quote
- Quoted before any work starts
- Telephone
- 01277 525 020
- Page updated
- 3 November 2026
Diagnose, treat, sign off
When we get to site, we report to your site contact and complete whatever induction the building runs. Floors, finishes and fittings next to the joints are covered before anything is cut or cleaned, with the work itself typically taking a day or two for a single block, longer for an estate programme. Rural sites near Broad Colney may need directions, gate codes or a contact on site. Add it to your enquiry and we’ll build it into the plan.
- We check the asbestos register for older buildings and look at the joints.
- 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.
Getting the site ready
- Share the asbestos register for older buildings
- Make sure the joints can be reached
- Share your working hours and any access restrictions
Request a quote
The quickest route to a quote is a few photographs and the site postcode. Send them through the quote form, or speak to us on 01277 525 020 or email the details over if you’d rather talk the job through.
Related advice
Why deal with it now?
Piecemeal repairs over the years often leave mismatched sealant. Resealing a whole building gives a consistent finish. Around Broad Colney, it’s better to renew all the failing joints at once. Photos of every joint help us quote for the whole job.
Access often affects the price as much as the sealing: joints within easy reach take less time than ones that need access equipment. Mention the access as part of your enquiry.
Why appoint us
- Constructionline member for supplier checks
- CSCS-carded applicators
- Workmanship guaranteed for 12 months
- One contact handling all your sites
Read our cost guide and our accreditations.
Block-wide mastic in Broad Colney
Rainfall across the South East, Broad Colney included, is lower than in many parts of the UK. External mastic still waits for dry faces and the right temperature, while the elevations that take the most sun tend to show hardened mastic first. Broad Colney lies roughly 17 miles out from central London. Managed blocks of flats are a big part of commuter-belt property; their frame mastic often ages block-wide.
Site managers at schools like Saint Bernadette Catholic Primary School can fit frame mastic into the summer works. Student blocks close to universities like University of Hertfordshire (3.6 miles north-east of Broad Colney) are easiest to work on between tenancies.
Broad Colney is about 3 miles south-east of St Albans, in Hertfordshire. Any commercial site in Broad Colney is covered, for single jobs and planned programmes alike. Our Hertfordshire coverage takes in 371 places. Our London page has more on work in that area (17 miles or so).
If you need mastic sealing in AL2, the process matches everywhere else we work: details, then a fixed price, then sealing and a 12-month guarantee. If your building is just outside Broad Colney, we cover London Colney (1 mile north), Shenleybury (1 mile south-east), Tyttenhanger (2 miles north), Sleapshyde (3 miles north-east) and Colney Heath (3 miles north-east). A short drive away, we cover Watford (6 miles south-west), Hemel Hempstead (7 miles west), Stevenage (14 miles north), St Albans (3 miles north-west), Welwyn Garden City (7 miles north-east) and Harpenden (7 miles north).
What’s near Broad Colney
Locally, jobs take us to sites close to The White Lion pub and Samuel Ryder Academy and the streets around them. The closest station to Broad Colney is Park Street station, about 1.9 miles north-west of the centre. A little further out are Hilfield Castle (4.5 miles south) and Radlett and District Museum (2.5 miles south). Open spaces near Broad Colney include Verulamium Lake and Broad Colney Lakes.
Also near Broad Colney
Other services in Broad Colney
What we can’t put right
Our job is the joint, not everything around it. On its own, sealant can’t deal with:
- Broken glass or failed sealed units
- Roof leaks, gutters or failed flashings that aren’t sealant joints
- Old mastic suspected of containing asbestos, which must be tested and dealt with by a specialist first
If in doubt, speak to us on 01277 525 020 or email us and we’ll say what we think.
Where we work in Broad Colney
- Shopfronts below residential blocks
- Communal kitchens and washrooms
- Window and door perimeters on blocks
- Balcony and threshold joints
- External wall and movement joints
- Communal entrances and stairwells
Work for main contractors and building owners
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.
Facilities managers want contractors who arrive with the paperwork sorted. Tell us what site paperwork you need, such as RAMS, an insurance certificate or CSCS details, and we will confirm with the quote.
Common questions from Broad Colney clients
Does your area include sites such as Colney Fields Shopping Park, near Broad Colney?
Yes. Estates, retail parks and business parks around Broad Colney, Colney Fields Shopping Park among them, are all within reach. Photos and a short description are enough for a first look.
Will you take on a block within reach of Park Street station?
Yes, and several blocks can go on one quote. Send the address, photos of the elevations and your access arrangements, and we will give a fixed quote.
How long does a job like this take?
That varies with the scale of the job, but the work typically takes a few days for most blocks, with larger programmes scheduled building by building. Larger or phased jobs take longer, and we will give you a timescale with the quote.
Do you do block-wide mastic programmes?
Block-wide and estate programmes are common. The quote can be split however suits your budgeting.
Do you check for asbestos in old sealant?
In older buildings, old mastic can contain asbestos. We check the asbestos register or survey before disturbing it and suspect material is tested first.
Do you cover Broad Colney?
Yes. Sites across Broad Colney are covered, with one number for every area we cover.
Can you follow the specification on our project?
Yes. Include it with the drawings when you ask for a quote, and we will price the work to it.
Site staff or a sealant specialist?
Some joints are best left to specialists: fire-rated seals that must follow a tested detail, trafficked floor joints and external movement joints among them. Getting these wrong usually costs more in the end than doing them right.
The visible bead is only part of the job. Backing rod, primer where specified and a joint designed to move with the building are where general trades tend to cut corners.
What we’re called out for in Broad Colney
Topping up old mastic is a common shortcut. New sealant won’t grip failed sealant, so these repairs rarely last.
Common reasons buildings call us in:
- Cracked, hardened mastic round windows on a block
- Complaints coming in block by block
- Draughts at frames across a block
- Water getting in round frames after rain
Churches, halls and community buildings such as Church of St Peter are looked after by trustees and committees like any other owner, and their frames, doors and external joints need mastic renewed in time.
What your quote should include
- Proof of insurance
- Whether their applicators hold CSCS cards
- Which product they’ll use, and why it suits the joint
- Health and safety accreditation such as CHAS