Facade Sealing in Old Knebworth
Facade sealing for Old Knebworth, from a contractor working since 2005. Fully insured, with a 12-month guarantee.
- Facade joints cracked through the middle
- Water coming in around window frames
- Unsightly perimeter sealant on a visible elevation
Facade sealing near Old Knebworth
Tell us what needs sealing and where, with photos or drawings if you have them, and we’ll price it.
Sites and facades in and around Old Knebworth
The South East is one of the drier parts of the UK. Winter mornings still bring frost and condensation on frames and panels, so the external programme keeps a little slack. At about 26 miles from central London, Old Knebworth is within reach of the capital. Building activity in the commuter belt runs from new flats near stations to business park refurbishments, and each scheme needs its mastic sealed to programme.
For contractors at a school such as Barnwell School, sealing has to be finished before term starts. Projects at colleges like North Hertfordshire College - Stevenage Campus (to the north of Old Knebworth) tend to run to term dates, so the mastic is planned tightly.
Old Knebworth is about 3 miles south-west of Stevenage, in Hertfordshire. Any commercial site in Old Knebworth is covered. We work across 371 places in Hertfordshire, large and small. For work in that direction, see our London page.
If you need facade sealing in SG3, the process matches everywhere else we work: send details, get a quote, we seal, guaranteed. Buildings on Old Knebworth Lane and Park Lane are within our area. We also cover Nup End Green (1 mile south-west), Driver's End (1 mile south-west), Rableyheath (1 mile south), Pottersheath (1 mile south) and Langley (2 miles north-west). A short drive away, we cover Hemel Hempstead (13 miles south-west), Stevenage (3 miles north-east), St Albans (10 miles south-west), Welwyn Garden City (5 miles south), Harpenden (7 miles south-west) and Hitchin (6 miles north-west).
Local landmarks in Old Knebworth
In Old Knebworth, that means premises near Knebworth Park and Robin Hood And Little John Public House. For rail, the closest station is Knebworth station, roughly 1 mile east. Well-known places in the area include Lister Hospital (3.7 miles north) and Stevenage Museum (2.2 miles north). For a walk, there’s Mardley Heath.
Facade sealing for commercial buildings in Old Knebworth
We are often asked to look at water coming in around frames. Failed perimeter sealant is a frequent cause, though that isn’t the only cause. We will tell you if we think the leak is coming from somewhere sealant won’t fix. If you’re dealing with perimeter joints where frames meet the structure and gaps between rainscreen or cladding panels, we can help. Sealant applicators who only do sealant are a different proposition from a general trade with a gun in the van: in Old Knebworth, that means joint design, primers and backing rod as standard.
Conversions of older rural buildings near smaller places such as Old Knebworth bring stone, flint, brick and timber up against new glazing. Those joints need a sealant that suits an uneven, sometimes porous surface, and often a colour chosen for the building.
Whoever the client is, the cover is the same: twelve months on the work we carried out. It doesn’t extend to damage, faults in the building or work by others, and we are upfront about that.
- Place
- Old Knebworth (SG3)
- Region
- Hertfordshire
- Cover
- A 12-month guarantee
- Price
- Fixed quote, scope in writing
- Telephone
- 01277 525 020
- Page updated
- 3 November 2026
Nearby places to Old Knebworth
Other services in Old Knebworth
How a job runs
Our CSCS-carded applicators arrive with the sealants, primers and backing rod the job calls for. Joint faces are cleaned back to sound, dry surfaces, the manufacturer’s primer is applied where it’s called for, and the sealant is tooled off neatly. Smaller jobs around Old Knebworth can be grouped with others nearby, which keeps travel down. You will have a fixed quote before work starts.
- Photos, drawings or a visit tell us about the joints and the access.
- We confirm the joint type, movement and the specified product.
- Failed beads are removed in full and both faces cleaned back.
- Primer is applied where the maker specifies it.
- Backing rod is fitted and the new sealant gunned in and tooled.
- The finished joints are checked with you.
What we need from you
- Send your site hours and access windows
- Share the asbestos register for older buildings
- Arrange parking or a loading space
Quotes
We quote a fixed sum against the scope you give us, so the cost is agreed before work starts. To ask for one, give us a call on 01277 525 020 or use the quote form.
Related advice
What we can’t put right
Honesty saves time and money. New sealant won’t cure:
- Damp caused by condensation inside the building
- Replacing glass or failed glazing units
- Cracked or spalling substrates that need repair before sealing
Not sure which it is? You can call 01277 525 020 or send photos by email and we will tell you honestly before you book.
Joints and surfaces we work on
- Shopfront frames
- Stone and brick facade joints
- Cladding panel joints
- Coping and flashing joints
- Perimeter joints where frames meet the structure
- Window and door perimeters
Leave it or put it right?
Patch repairs over old sealant tend to come back. A full cut-out and reseal costs more on the day but lasts much longer. Around Old Knebworth, it’s better to renew all the failing joints at once, rather than one at a time. Send photos of each area and we’ll quote for the lot.
Quantities, awkward access and phased working all shape the price. Site requirements like inductions and permits play a part as well, along with the time of year for external work.
What you get with us
- Colours confirmed for the specified product
- Fixed quotes based on photographs, drawings or a visit
- Over 20 years of commercial sealing
- One contact handling all your sites
Read how commercial sealant jobs are priced and our accreditations and insurance.
Questions we’re asked in Old Knebworth
Does your area include sites such as Arlington Business Park, near Old Knebworth?
Yes. Estates, retail parks and business parks around Old Knebworth, Arlington Business Park among them, are all within reach. Send details of the unit and the work through our quote form for a quick quote.
Can work at a site such as North Hertfordshire College - Stevenage Campus fit around teaching?
Yes. Tell us the term dates, vacation periods and access windows, and we’ll plan the work around them. We’re CHAS accredited and a Constructionline member, and paperwork such as RAMS is confirmed with the quote.
Can you follow the specification on our project?
Yes. Send it with your enquiry, and the quote will be based on it.
How do I request a quote?
It works in four steps: send details, receive a fixed quote, we carry out the work, and it’s guaranteed. The first step only needs photographs and a postcode.
How long before the joints can be used?
Curing time varies by product, and we confirm it on the day.
Do you hold CHAS accreditation?
Yes. Mastic Doctor is CHAS accredited and a Constructionline member.
Can you just add new sealant on top?
No. Overlaying is a shortcut that peels away quickly. Our method is a full cut-out, cleaning, backing and a new bead.
Common problems we fix in Old Knebworth
The wrong product causes its share of trouble: acetoxy-cure silicone may mark stone or corrode certain metals, and an interior product won’t last outdoors. Neutral-cure, facade-grade products are what most external joints need.
Look out for the following:
- New sealant peeling off old mastic
- Failed seals around shopfront and entrance frames
- Air leaks through failed facade joints
- Leaks at window and door perimeters
For contractors refurbishing units at places like Arlington Business Park, which lies north of Old Knebworth, the mastic covers cladding panels, roller-door and window perimeters.
Comparing quotes
- Their public liability cover
- Are they CHAS accredited or on Constructionline?
- How joint depth will be controlled
- Will RAMS and insurance details be available?
What affects the price in Old Knebworth
We price every job individually. The things that drive the figure:
- Any access equipment needed
- Which sealant the job calls for
- Whether the work must be split into stages
- Distance, for remote addresses
The work involved drives the cost: removing old material, preparing the joints, the product, the access and how the work is phased. Call for a quote and we will explain how it’s made up.
Sending details for a quote
It doesn’t need to be a full survey. These details are enough to start:
- Photos of the joints, close up and from further back
- Rough lengths or quantities, or drawings if you have them
- What the building is and how it’s used
- Any dates the work must fit around
Let us know the site, the scope and your timescale, and we will put a fixed quote together. The easiest way is to ring 01277 525 020 or send photos by email.
Different surfaces, different methods
Brick and stone facades
Stone can absorb plasticisers from the wrong sealant. We use a product suitable for the stone where the specification names one, and mask the edges carefully.
Precast concrete panels
Precast arrises sometimes crumble or carry old residue. Faces are cleaned to sound concrete, and damaged edges are reported before sealing.