Hertfordshire · England
Oaklands Window Mastic
Mastic around window and door frames, sills and patio doors in Oaklands, with a 12-month guarantee on every job. Ask us for a quote.
- Untidy mastic left by window fitters
- Cracked internal joints between frame and plaster
- Leaking joints at the ends of sills
Aftercare tips
A little care helps the new joints last. Our advice:
- Don’t aim a pressure washer at the joints
- Repaint timber before it’s bare
- Don’t use solvent cleaners on the joint
- Check the mastic once a year
Clean the frames with mild soapy water, and keep solvents and harsh chemicals off the joint.
A small gap around a frame only grows. As old mastic keeps shrinking, the gap widens, and heat escapes around the frame. A new joint closes it up.
How we handle window mastic in Oaklands
The new joint does not have to be white. White, brown, anthracite grey, black and clear sealants are all available, so the line suits the frame instead of standing out. We work on patio & French doors, composite doors and uPVC windows, and the jobs we see most are mastic that has split away from the wall and mastic that’s falling out in pieces.
Homes around Oaklands range from older properties to newer houses, and their windows range just as widely. The right sealant depends on the frame and on what it sits in.
Big or small, it’s backed by our one-year guarantee.
- Location
- Oaklands (AL6)
- Wider area
- Hertfordshire
- Guarantee
- 12 months on all our work
- Quotes
- A clear price before any work starts
- Call
- 0345 464 0079
- Updated
- 26 October 2026
DIY sealant or a professional job?
Some jobs are best left to a professional: work at height, external movement joints, fire-rated sealant and large areas need the right product, the right access and the right method.
Sealing over old silicone is the commonest DIY error. Silicone doesn’t stick to old silicone, so it lifts and traps water and mould underneath. Everything old must be removed first.
Common questions in Oaklands
Is Oaklands in your area for window mastic?
Yes. Our work covers London and the South East, and Oaklands is part of that. Just call 0345 464 0079 or drop us an email with a few details of the job, and we will give you a clear quote.
Can you help a landlord with a rental near Welwyn North station?
Yes, landlords and agents are among the people we work for. You can call 0345 464 0079 or send us an email with the details for a clear quote.
Where are you based?
We are based in Crawley, and we cover South East England, London and all of Scotland.
Will you leave a mess?
No. We protect the surfaces around the joints, and we clear up the old sealant and our materials before we leave.
Are you an approved applicator?
Yes. We’re approved under the ARBOMaster scheme, the approved applicator scheme for Arbo sealants.
Is there any odour?
Sometimes, a little. It fades as the sealant cures, and ventilation helps.
How long before the joint can be used?
Many sealants skin over quickly but take longer to cure fully. We will tell you how long to leave the joint before we leave.
Do you do commercial work?
Yes. Hotels, offices and other businesses use us and we’re fully insured.
Window mastic in Oaklands: local notes
Compared with the north and west, the South East gets less rain, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind. With historic houses such as Digswell House (about 1.8 miles south) nearby, there’s older building stock in the area around Oaklands as well as newer homes. In older buildings, older timber frames in brick or stone need a different approach from a modern uPVC window.
For landlords with property near Welwyn North station, sound mastic around windows and doors keeps out the draughts and damp that tenants notice first. For site and facilities teams at buildings such as Oaklands Primary School, the mastic around its windows and doors needs looking after like any other building’s.
Oaklands is about 3 miles north of Welwyn Garden City, in Hertfordshire. Every kind of property in Oaklands can book us for window mastic. Every job comes with our 12-month guarantee. Oaklands is one of 381 towns and villages in Hertfordshire we cover for window mastic. We also work in London, around 24 miles away.
All of AL6 is covered for window mastic. Whether your property is on Briary Wood End, Lower Mardley Hill and Heathbrow Road or anywhere close by, our applicators can take on the job. Other places close to Oaklands include Woolmer Green (1 mile north-east), Harmer Green (1 mile south-east), Burnham Green (1 mile south-east), Datchworth (2 miles north-east) and Knebworth (2 miles north). Further out, we also cover Watford (15 miles south-west), Hemel Hempstead (13 miles south-west), Stevenage (5 miles north), St Albans (9 miles south-west), Bishop's Stortford (15 miles east) and Welwyn Garden City (3 miles south).
Local landmarks in Oaklands
We work in homes and buildings around Monk's Walk School, Danesbury Park and The North Star pub and the streets around them. Oaklands’s nearest station is Welwyn North station, roughly 1.3 miles south of the centre. Other landmarks nearby include Queen Elizabeth II Hospital (4.2 miles south) and Datchworth Museum (1.5 miles east). The countryside around Oaklands includes Mardley Heath.
Why deal with it now?
Getting a straight, even bead on an outside frame takes practice, especially on upper floors. We cut out properly, back deep gaps and tool every joint neatly, using a product chosen for the frame and wall. In an older home around Oaklands, damp from a failed joint can get into timber and plaster, which is far harder to put right than the sealant itself.
No two jobs are quite the same, so we quote each one individually. Size, access and the product the joint needs all make a difference, and we’ll explain the quote if you ask.
Why us?
- Anti-fungal silicone where joints get wet
- Approved under the ARBOMaster scheme
- Tidy, careful work
- Fully insured
See our cost guide and what customers say.
Towns and villages near Oaklands
Also in Oaklands
Surface by surface
Timber windows & doors
Wood swells when it’s wet and shrinks when it dries, so the joint must stay flexible. We seal onto sound, dry paintwork or timber.
Composite doors
If the door itself is draughty, the issue may be the door seals or hinges rather than the frame mastic. We’ll tell you if that is what we find.
What affects the quote in Oaklands
Some jobs are bigger than they look, and some smaller. The main factors:
- Whether the work is at height
- How much there is to do
- Any working-time requirements on site
- Any mould that needs treating
We do not show prices on the website, because the cost depends so much on the job itself. For a quick quote, please phone 0345 464 0079 or drop us an email and we will talk you through it.
What we need to know
To make quoting easier, let us know:
- How many joints, rooms or windows are involved
- Access, such as stairs, a lift or height
- The address or postcode of the job
- Whether it has been sealed before
To get a quote, call 0345 464 0079 or send us an email and tell us where the job is and what the problem looks like. You will have a clear quote before work begins.
What we do, step by step
Once we’re on site, we compare the joints with what we discussed. If we find something unexpected, we talk it through with you first. After that, the work takes a few hours for a handful of frames, longer for a whole house. For a job in Oaklands, we agree the time, the access and parking before the day. If the work is outside, the weather plays a part, as sealant needs a dry surface.
- Each frame is looked over and we agree which ones need resealing.
- We remove the old mastic and clean the frame edge and wall.
- Deep gaps get closed-cell backing rod to set the depth.
- A flexible exterior sealant is applied in a colour to suit the frame.
- Every joint is tooled smooth and checked before we leave.
Before we arrive
- Clear items away from the joints we’re working on
- Where the joints are inside, avoid wetting them before we arrive
- Tell us about access, such as stairs, a lift or high-level joints
Ask for a quote
Want a quote for window mastic? Please phone 0345 464 0079 or email us and tell us about the job. You will know what we plan to do, and what it will cost, before any work begins.
Related advice
Common problems we fix in Oaklands
A lot of older mastic was never designed to stay flexible. Once it’s rigid, every bit of frame movement pulls at it, and a gap opens along one edge.
The most common problems we see are:
- White mastic on grey or black frames
- Old mastic that has gone black or come away
- Whistling draughts around closed windows
- Draughty joints inside around the window
If you live in an older home near Church of St Michael and All Angels, the joint between an old wall and a newer frame is usually the first place rain gets in.
Before booking anyone
- What insurance they hold
- Which sealant they’ll use, and why
- What happens if they find a problem under the old sealant
- How long to leave it before use