Essex · England

Window Mastic in Harlow

Window mastic in Harlow from a team with over 20 years’ experience. Rated 4.9 on Google from 180+ five-star reviews.

  • Gaps where the sill meets the wall
  • Old mastic that has gone black or come away
  • Rain getting in at the frame or under the sill

Window mastic in Harlow

How we handle window mastic in Harlow

There are two joints on most windows. Outside, the mastic keeps rain out; the internal joint closes the gap to the plaster and stops draughts. Either or both can be done. If you have draughts coming in around windows and doors and leaking joints at the ends of sills, we can put it right, whatever the surface.

Plenty of homes in a town like Harlow have had conservatories, patio doors or new windows added over the years. Every addition brings more joints, each wearing at its own pace. Leaks generally start at a sill, a frame head or a glazing joint.

The work is guaranteed for twelve months. If there’s a problem with our work within the year, let us know and we’ll sort it.

Outdoor mastic being applied where a white frame meets red brickwork, below the fascia and gutter
Where
Harlow (CM17, CM20, CM18, CM19)
Region
Essex
Cover
One year on every job
Quote
A clear price before work begins
Phone
0345 464 0079
Updated
26 October 2026

What window mastic looks like in Harlow

Harlow is one of the post-war new towns. With many homes from the post-war decades, replacement windows and doors are common. The mastic around replacement frames ages too, and gaps at sills and frame heads are where water gets in. The South East is one of the drier parts of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.

Rented homes near Harlow Town station change hands often, and renewing tired window mastic between tenants heads off draught and damp complaints. Managing a site like Cooks Spinney Primary Academy and Nursery? Then the mastic around its windows and doors needs looking after like any other building’s.

Harlow is about 21 miles north-east of London, in Essex. Our applicators cover window mastic for homes and businesses in Harlow and nearby, as part of our work across Essex. Our area takes in 644 places across Essex, large and small. Chelmsford is on our list too, around 16 miles away.

We work across the CM17, CM20, CM18 and CM19 postcode area for window mastic and the streets around it. We cover properties on London Road, Soper Square and Square Street and the roads around them. With the A414 and A1019 close by, Harlow is simple for us to get to. If you are just outside Harlow, we cover Mark Hall South (1 mile north-east), Netteswell (1 mile west), Latton (1 mile south-east), Mark Hall North (1 mile north) and Bush Fair (1 mile south). Within a short drive, we also cover Brentwood (13 miles south-east), Loughton (9 miles south), Waltham Abbey (7 miles south-west), Great Dunmow (13 miles north-east), Epping (5 miles south) and Stansted Mountfitchet (10 miles north). As one of the bigger places in Essex, Harlow has homes, rented property and businesses of every kind.

Landmarks near Harlow

Around Harlow, our work takes us to homes and buildings near Harlow Marsh, Purple Emperor pub and BMAT STEM Academy. Harlow’s nearest station is Harlow Town station, about 1.2 miles north-west. Other landmarks nearby include Princess Alexandra Hospital (1.2 miles west) and Mark Hall Cycle Museum (0.7 miles north-east). For a walk, there’s Hunsdon Mead.

Map of Harlow © OpenStreetMap contributors

Work for landlords, hotels and businesses

Housing providers, facilities teams and property managers book us too in Harlow and across Essex. We can quote a run of properties together, and we are fully insured for the work.

Water getting past a failed joint can damage the building, which is a bigger problem in a rented property. Keeping joints in good order is simple maintenance.

What we do, step by step

We bring everything the job needs with us. Once we’ve agreed what’s being done, we protect the area and start. Most jobs take a morning for a couple of windows and a door. A visit in Harlow needs access to the work and a place to park close by. For outside work, let us know about side access, gates and any upper-floor joints.

  1. We start by checking each window and door with you.
  2. Next the failed sealant is cut away and the joint cleaned.
  3. We fit backing rod in deep gaps so the sealant is the right depth.
  4. We apply a weatherproof sealant to match the frame and tool it neatly.
  5. Every joint is checked before we leave.

Getting ready for the visit

  • For indoor joints, keep the area dry beforehand if you can
  • Let us know if you’ve seen damp or leaks
  • Tell us about access, such as stairs, a lift or high-level joints

Get a quote

Asking for a quote is easy: tell us what needs doing and where, and roughly how big it is. A few pictures by email make the job easier to understand, and we will come back to you with a quote.

Ask for a quote

Related advice

Harlow questions

Is Harlow in your area for window mastic?

Yes, Harlow is within the area we cover. Our work covers London and the South East. Just call 0345 464 0079 or drop us an email with a few details of the job, and we’ll give you a clear price.

Can you help a landlord with a rental near Harlow Town station?

Yes, rental work is part of what we do. Just ring 0345 464 0079 or email us and tell us about the property, and we will give you a clear price.

How do I get a quote for window mastic in Harlow?

It depends on the job, so we quote each one individually. To get one, phone 0345 464 0079 or drop us an email with a short description of the job.

What information do you need?

Tell us what needs doing and where, with pictures by email if possible. We’ll ask anything else we need to know.

Where do you work from?

We are a Crawley-based firm, with over 20 years’ experience. Our area covers South East England, London and Scotland.

Does someone need to be in?

That depends on where the joints are. For work indoors, someone needs to let us in.

Are you fully insured?

Yes. Mr Mastic is fully insured, with over 20 years’ experience in sealant work.

Can I do it myself?

Sometimes. The key is preparation: remove all the old material and work on a clean, dry joint. If it does not work out, we can redo it.

DIY versus a professional finish

A careful DIYer can reseal a simple joint, like a short, easy-to-reach joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.

If you do try it yourself, take your time over the preparation: take out all the old sealant, make sure the joint is clean and dry, and give it the full cure time. If it doesn’t work out, we can still put it right.

What the job involves on each surface

Aluminium frames

Metal frames expand in the sun and are often slim, with little room for error. A neat, narrow bead in a colour to match keeps the clean look.

Composite doors

Front doors take the weather head on, and the top and bottom corners tend to fail first. Those corners get the most care.

Aftercare tips

Once the sealant has cured, a few habits help it last:

  • Keep paint and stain on wooden frames in good order
  • Use gentle cleaners on frames and sealant
  • Paint up to the joint, not over it
  • Air rooms to keep condensation down around windows

Have a look at the joints once a year, ideally after winter. Cracks and lifting edges are easy to spot early, and if anything looks wrong, just call 0345 464 0079 or email us.

A small gap around a frame only grows. As old mastic keeps shrinking, the gap widens, and a cold room gets colder. Resealing closes it.

What affects the quote in Harlow

Jobs vary more than people expect. The main factors:

  • The type of sealant required
  • Access and height
  • Working hours on commercial sites
  • How much old sealant there is and how hard it is to remove

Rather than a set price list, we look at what your job involves: the amount of work, the old material and the access. You’ll know the price before we begin.

What to tell us for a quote

Photos by email are helpful but not essential. Try to tell us:

  • What the problem is, such as mould, gaps, leaks or cracking
  • The type of property
  • Pictures of the joints, sent by email
  • Where the property is

If you’re in Harlow and need window mastic, ring 0345 464 0079 or drop us an email. Tell us what the problem is and where, and you will get a clear quote before any work starts.

Common problems we fix in Harlow

Every frame moves through the day. Sun on a frame makes it expand, and it contracts again overnight, while the brick or render around it hardly moves. A sealant that cannot keep up eventually tears.

Signs it’s time to call us include:

  • Draughty joints inside around the window
  • A bead that doesn’t match the frame
  • Untidy mastic left by window fitters
  • Hard, cracked sealant around windows

For an older house near a landmark such as St Andrew's Methodist Church, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint.

Questions to ask before you book

  • What guarantee comes with the work
  • Which sealant they’ll use, and why
  • How much experience the applicator has
  • Whether VAT is included

10 questions to ask before booking

20+ yearsMastic and sealant specialists
ARBOMaster approvedApproved applicator for Arbo sealants
Fully insuredDomestic, commercial and hotels
One-year guaranteeOn every job