South East England and London

Sand Mastic in Hertfordshire

From the largest town to the smallest village in Hertfordshire, our applicators can help with sand mastic. A clear quote before we start, and a one-year guarantee.

Sand Mastic across Hertfordshire

Call 0345 464 0079

Get a quick quote

Towns we cover in Hertfordshire

Traditional burnt sand mastic around sash and case windows and doors in stone and brick. Choose your town from the list to see local details, or call or email us for a quick quote.

Largest places

Our sand mastic service in Hertfordshire

Traditional burnt sand mastic that sits naturally against stone and brick. It suits period and listed homes where a modern sealant bead would stand out. We work on sash and case windows, period & listed homes and stone surrounds, and common reasons people get in touch are gaps round a timber door in stone or brick and open joints round the window box.

Good joint work is mostly preparation, and we don’t rush it. Every joint is cleaned and dried before new material goes in. In total, it generally takes anything from a few hours to a full day, depending on how many windows.

We check the window surrounds and agree which joints need renewing.
The loose and crumbling mastic is raked out and the joint cleaned.
Large voids are packed out first, so the mastic is not too thick.
We mix the sand mastic and apply it by hand, shaping it to the joint.
The finish is dressed so it sits neatly against the stone or brick.

How we quote

A failed joint rarely gets cheaper to fix by waiting, as water and mould keep getting in. If you’re unsure, phone 0345 464 0079 or email us and we’ll give you an honest view and a quote.

Why choose Mr Mastic

12-month guarantee on every job
Full insurance on every job
20+ years of sealant experience
Homes, businesses and hotels

How to get a quote

Quotes start with a quick conversation. Describe the problem, the location and the size of the job. Whenever you’re ready, phone 0345 464 0079 or send us an email.

What’s near Watford

Locally, jobs take us to homes and businesses close to The Estcourt Arms, Watford St John's Church of England Primary School and Church of St Andrew, among other places. You will also find Cassiobury Park (0.8 miles west) and The Watford UTC (0.5 miles east). There’s a railway station in Watford itself: Watford Junction station. A little further out are Hilfield Castle (2.8 miles east) and Charter Place (0.5 miles south). Open spaces near Watford include Harrow Weald Common.

Windows and doors across Hertfordshire

In Hertfordshire, sand mastic work takes in houses, flats, conservatories and commercial glazing, in Watford, Hemel Hempstead and Stevenage and well beyond. Every outside joint is sealed dry and clean, so the forecast plays its part.

London and the South East have homes from every era, from period terraces to post-war new towns and new estates. The right sealant depends on the age and materials of the building, wherever it is in Hertfordshire.

Watford: For landlords with property near Watford Junction station, cracked sand mastic around sash windows lets in the draughts tenants complain about. Homes close to Church of St Andrew include some older properties, and replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint.

Signs you need sand mastic

Scraping and sanding before painting can loosen old mastic. It’s often found when windows are being prepared for paint.

The most common problems we see are:

Mastic that needs renewing before redecorating
Mastic dropping out of the joint
Draughty sash windows at the surround
Gaps round a timber door in stone or brick

When it isn’t the sealant

In fairness, some problems need a different trade:

Timber that has rotted
Cracked or broken glass
Decisions on consent for listed homes

Aftercare tips

No joint lasts for ever, but care makes a real difference. A few tips:

Plan mastic work ahead of painting
Don’t run silicone over sand mastic
Find out about consent before window work on a listed home
Check the mastic when you check the paintwork

Check the mastic when you check the paintwork. Catching cracks early keeps repairs small.

Small cracks are a sign the mastic is ageing. It’s easier to renew it before it drops out.

Can I do it myself?

If you are set on DIY, put the effort into preparation: remove every trace of old sealant, clean and dry the joint, and follow the product’s cure time. If it fails, we can still redo it.

The difference is mostly in the preparation and the product. Joints are cleaned back to sound surfaces and dried, and the sealant is chosen for how the joint moves and where it is, and the work is guaranteed for a year.

Why act early?

Draughts round a sash window aren’t always the sashes. Gaps between the frame and the wall can be just as bad and new mastic seals them.

What your quote should include

What happens if the job turns out different
Which colour the sealant will be
Whether all the old sealant comes out first
The length of the guarantee

FAQs for Hertfordshire

Can tenants book the work?

Yes, though it’s best to check with your landlord first. Landlords are often happy for the work to be arranged.

Is there any odour?

There can be a smell while the sealant cures, but it fades. Opening a window helps.

What is sand mastic?

It’s the traditional filler for the joint round timber windows and doors. It combines sand with a linseed-oil-based binder.

Is consent needed for window work on a listed home?

Check with your local planning authority. They’ll tell you if consent is needed for work to your windows.

How long does sand mastic take?

Typically it takes anything from a few hours to a full day, depending on how many windows. Bigger jobs take longer, and we will say how long yours will take.

Do you hold any approvals?

Yes. We are ARBOMaster approved, the scheme for applicators of Arbo sealants.

Are you insured?

Yes. Mr Mastic is fully insured, and we have been doing sealant work for more than 20 years.