Hertfordshire · TR19 inspections and grease testing
TR19 inspections and grease testing in Digswell, Hertfordshire
TR19 inspection across Digswell and nearby, booked around your opening hours and signed off in writing with photos.
- Ductwork where grease may be over the TR19 limits
- Sections of duct that can’t be reached
- Missing TR19 certificates or history
How we handle TR19 inspection in Digswell
Grease thickness testing tells you how much grease is sitting in the canopy, ducts and fan. We use the Wet Film Thickness Test (WFTT) or the Deposit Thickness Test (DTT), taking readings at set points. The results show whether the system needs cleaning and how soon. If you have sites with gaps in their extract records and extracts that have never been grease tested, we can help.
In a smaller place like Digswell, the kitchens with extract systems are more likely to be a pub, a café, a takeaway or a school or care home kitchen than a big restaurant. A kitchen that cooks fewer hours still builds up grease, so the interval is set by hours of use and grease readings.
Duct Doctor has been trading since 2009, and we’re a BESCA Vent Hygiene Elite member, cleaning to BESA TR19® Grease. We also hold CHAS, SafeContractor and ISO 9001, and we’re fully insured.
- Location
- Digswell (AL8, AL7, AL6)
- Wider area
- Hertfordshire
- Records
- TR19® certificate and photo report
- Price
- A fixed quote up front
- When we work
- Overnight and weekend work, 24/7 emergency callout
- Telephone
- 0345 646 2711
- Checked
- 30 October 2026
Why act early in Digswell
Post-clean verification shows whether the system was left the way the certificate says, while there’s still time to put anything right. Even a site near Digswell that is only busy part of the week needs its system checked on a schedule.
Every site is different, so each one gets its own fixed quote. The size of the job, how we reach it, its condition and the working hours all play a part.
What you get with us
- Evenings, overnight and weekends, plus 24/7 emergency callout
- A single point of contact for sites across the South East and London
- We diagnose before we treat
- Accredited under CHAS and SafeContractor, with ISO 9001
Your questions about TR19 inspection in Digswell
Is Digswell within the area you cover?
Yes. Digswell is within the area we cover across London and the South East. Photos of the system and directions to the site help us plan the visit.
Can you work in Digswell outside opening hours?
Yes, evening, overnight and weekend work is normal for us. That way a site in Digswell does not have to lose a day’s trading. Tell us your opening hours when you ask for a quote.
What grease levels does TR19 allow?
TR19® Grease says grease should not go over a mean of 200 microns between cleans. Any reading of 500 microns or more needs immediate spot cleaning.
What’s TR19?
It’s BESA’s specification and the benchmark insurers, fire officers and EHOs look to. It covers how systems are inspected, cleaned and checked and expects a risk-based approach.
What information do you need?
A short description and a few photos, with the address and opening hours. If we need more, we’ll ask.
How often should grease be tested?
Each report recommends when to test and clean next, based on the readings and how the kitchen is used. A risk assessment based on measured grease should set the interval.
Can we book visits on a schedule?
Yes. We run scheduled maintenance contracts, with visits at the interval your system needs. The report from each visit recommends the next date.
Will you produce a report for our insurer?
Yes. We inspect the system and produce a report with grease readings, photos and any inaccessible areas. It’s set out for your insurer or broker.
Grease, kitchens and Digswell
The FSA’s food hygiene register shows about 55 restaurants, cafés and canteens and about 13 takeaways across Digswell and its immediate surroundings (about a mile and a half). Where they cook under a canopy, a grease reading is the way to tell whether the extract is due a clean. Digswell is covered by Hertfordshire Fire and Rescue Service. Fire and rescue authorities enforce the Fire Safety Order in most non-domestic premises, and in a kitchen that fire risk includes the grease in the extract. It’s Welwyn Hatfield council that sends environmental health officers to food businesses in Digswell. They look at how clean the premises and equipment are, and the kitchen extract is part of that. A dated certificate in the maintenance file answers the question before it’s asked.
For kitchens close to Welwyn North station, where the day often starts early and ends late, the extract can be cleaned overnight. For schools such as Harwood Hill Junior Mixed Infant and Nursery School, kitchen extract cleaning is normally booked for the holidays, when the canteen is closed.
Digswell is about 1 mile north of Welwyn Garden City, in Hertfordshire. Anywhere in AL8, we cover TR19 inspection for commercial sites. Our area takes in 381 places across Hertfordshire, from busy centres to quieter spots. London is in our area too, around 23 miles away.
All of AL8, AL7 and AL6 is covered for TR19 inspection, from the main roads to the quietest streets. We cover sites on Adele Avenue, Station Road and Hertford Road and nearby roads. Close by, we work in Haldens (1 mile south-east), Harmer Green (1 mile north-east), Burnham Green (2 miles north-east), Oaklands (2 miles north) and Tewin (2 miles east). We also work in nearby towns such as Watford (14 miles south-west), Hemel Hempstead (12 miles west), Stevenage (6 miles north), St Albans (7 miles south-west), Harpenden (6 miles west) and Hitchin (10 miles north).
What’s near Digswell
In Digswell, that means kitchens and buildings near Hedgehog pub, Monk's Walk School and Danesbury Park. Digswell has its own railway station: Welwyn North station. Other landmarks nearby include Howard Centre (1.3 miles south) and Datchworth Museum (2.6 miles north-east). Not far away are Tewin Orchard and Hopkyns Wood.
Different parts, different methods
Schools, hospitals and care homes
We fit testing around service times and school holidays to avoid disruption.
Horizontal duct runs
Grease can gather thickly at bends and along long runs, out of sight of the kitchen.
How the visit works
When we arrive, we check the system against the survey or the pictures you sent. Anything unexpected is raised with you before we go further. After that, the work takes an hour or two for a single kitchen, longer for a large or complex system. For a site near Digswell, the work is booked around your opening hours, evenings and weekends included.
- We go through any past certificates and reports.
- The layout is traced from the canopy to the discharge.
- Access panels are located and any missing ones noted.
- Grease readings are taken and pictures recorded.
- We report back with readings and a fixed quote.
Getting ready for the visit
- Have your last certificate or report to hand
- Mention any locked doors, roof access or ceiling voids
- Agree a time when the area can be out of use
Ask for a quote
Photos are enough for some jobs, while others need a look on site. Big or complicated sites, and systems that are hard to see in photos, get a survey first. Either way, you get a fixed price before work begins.
Related advice
Looking after it afterwards
Good habits slow the build-up between visits. Our tips:
- Keep the route to access panels clear
- Book the next test on the date in the report
- Look out for grease drips round the canopy edge
- Clean or swap grease filters as often as the kitchen needs
Where sections couldn’t be reached, the report says where access panels would help. Fitting them before the next clean means the whole system gets done.
Keep certificates, reports and readings in one place so the history is easy to show.
When to call us in Digswell
Grease is fuel. Flames from the range can be pulled into the canopy and travel through the ducts to other parts of the building. Measuring it is the first step to keeping it under control.
Most sites get in touch when they notice something like this:
- Checking the result of a recent clean
- Systems that need surveying before cleaning
- An insurer’s request for a TR19 audit
- Parts of the system left out of past cleans
Volunteers running a hall kitchen near Digswell Village Church, or anywhere in Digswell, may not know when the extract was last cleaned, and a grease test settles it.
What your quote should include
- How areas they can’t reach will be recorded
- Whether the whole system is included, or only the parts that are easy to reach
- Whether they recommend a next date
- If they look at the system before pricing
What affects the quote in Digswell
Your quote is based on your site. We take into account:
- What state the system is in
- Working hours and out-of-hours timing
- The size of the system
- Whether several sites go on one quote
Putting the work off seldom saves money. Problems in a system tend to grow, and a neglected system can mean more work. If you’re not sure what’s needed, ring 0345 646 2711 or drop us a line and we’ll give you an honest view and a fixed quote.
Helping us quote
When you contact us, it’s useful to have:
- Your opening hours and when the area is out of use
- The postcode and the type of business
- A few general shots of the system
- The roof, plant room or outside wall the system runs to
If you need TR19 inspection in Digswell, call us on 0345 646 2711 or send us an email. Let us know the site type and the opening hours, plus pictures or the previous report if they’re to hand. A fixed quote usually follows within one working day.
What staff can safely do
Staff cleaning doesn’t replace a specialist visit; it supports it. Regular in-house cleaning slows the build-up, but hidden parts of the system still need specialist attention.
If your staff spot something between visits, like drips, unusual noise, smells or damaged filters, it’s best reported rather than tackled in-house. We can diagnose it and quote.