.jpg?width=300&name=IMAGE%20(19).jpg)
Frequently asked questions.
Whatever questions you might have about our range of products and services, we’re here to help. Here’s some of our most frequently asked questions.
How can we help you?
If you can’t find the answer you are looking for here, please do get in touch.
What are your lead times?
We are proud to offer a standard lead time of 6 weeks after sign-off.
Who can install a fire door?
There's no legal requirement for a fire door installer to hold a specific certificate - such as BM TRADA Q-Mark, FIRAS or BWF-CERTIFIRE - but the law does require competence: the installer must do the job correctly, and the doorset must be fitted in line with the manufacturer's instructions and its fire certification. Because every public building must be protected against the spread of fire, building control officers will often ask an installer to demonstrate competency before accepting the installation. We're also increasingly seeing clients and contractors specify that installers hold some form of third-party certification. It matters, too: an incorrectly installed fire door will not be compliant and can offer very little protection, or none at all.
Explain LRV values?
LRV stands for Light Reflectance Value, which is a measure of how much visible light is reflected from a surface when illuminated by a light source. Further details and an LRV calculator can be found here.
What is Effective Clear Width?
The Building Regulations Approved Document Part M (BS 8300-2:2018), sets out minimum widths for doorways to ensure that all users (particularly wheelchair users) are able to gain unrestricted access. These minimum widths can be are known as ‘Effective Clear Widths’. Further details, and an Effective Clear Widths calculator can be found here.
What are the maximum gaps allowed around a fire door?
The maximum permitted undercut that we can currently certify is 8mm for fire-rated doors. The 3mm undercut for smoke-rated doors is no longer permitted. Single-swing smoke-rated doors must be fitted with a drop-down seal, leaving no gap when the door is closed, and double-acting doors must be fitted with a fir tree seal, which maintains continuous, low-pressure contact with the floor, leaving no gap.
Do your doors have a manufacturer’s warranty?
Yes - SDS doorsets come with a manufacturer's warranty of between 5 and 10 years, subject to range and standard terms of use, giving you confidence in their quality and long-term performance.
Why is PVC edge protection better than aluminium?
Aluminium edge protectors are renowned for leaving sharp edges or even protruding metal fragments in the event of an impact. PVC edge protectors do not do this, yet they offer an equal resistance to impact. PVC edge protectors are also available in any of our defend colour range, meaning that if a contrasting colour is required for building regs, this can be easily achieved. Further benefits include the ease of machining for locks and keeps compared to aluminium.
Do you do a range of compatible ironmongery?
Every SDS doorset can be finished with our complete range of compatible ironmongery, so the whole assembly comes tested and certified from one source. Further details can be found here.
What is anti-microbial ironmongery and how does it work?
Anti-microbial ironmongery is treated with a coating containing silver ions, which destroy the cell membranes of germs on the surface, causing them to break down and die - an added layer of infection control on the surfaces people touch most. It's worth noting that not all ironmongery is anti-microbial; SDS sources anti-microbial ironmongery (Define + ) on request, so let us know if you'd like it specified for your project.
How does the Copper Nickel kill bacteria?
The copper-nickel alloy features antibacterial properties which work 24/7, never washing out or wearing away, making it the ideal choice where infection control is paramount. Our Define Copper range of ironmongery is manufactured using a 70-30 copper-nickel alloy, which makes the range tarnish-resistant and will not oxidise and patinate like pure copper.
Can you colour match any colour with your PVC?
SDS have a large colour range but can colour match to a specific RAL or Pantone colour references in some cases, subject to minimum lead times and order quantities.
Do we offer more colours than we show on our swatch?
Our full colour range is available online — you can view it here.
We do also offer a colour matching service for shades beyond the standard range, though we don't usually recommend it: colour matching carries a minimum order quantity, which can make smaller orders and future maintenance harder to manage. For most projects, specifying from the standard range keeps replacements and repairs straightforward.
What is a Part M compliant vision panel?
There is a minimum zone of visibility required for all glazed doors to ensure user safety. This is set out in the Building Regulations Approved Document Part M (BS8300) and the Equality Act (EA) 2010. SDS offer a number of standard vision panel designs which are part M compliant. Further details of these designs can be found here.
What areas are suitable for Dfendoor and Shieldoor?
Dfendoor is designed for high-impact, high-traffic hospital environments, such as A&E, wards, corridors, and ICU/HDU areas, where doors take constant contact from beds, trolleys and equipment. Shieldoor is our radiation-shielding doorset, suited to spaces where controlling radiation is essential, such as radiology, imaging and X-ray rooms, theatres and laboratories.
Are Dfendoor and Shieldoor doorsets sustainable?
Yes — sustainability is built into how Dfendoor doorsets are designed, manufactured and maintained.
Our doorsets are manufactured in Hampshire in the UK, which keeps transport emissions low and supply chains short. Dfendoor and Shieldoor doorsets are FSC® Mix certified, meaning they are made of material from well-managed, FSC®-certified forests and other controlled sources. FSC® C131164.
The bigger sustainability gain, though, is longevity. A doorset specified correctly for its clinical environment lasts longer, needs fewer interventions and is far less likely to be replaced early — which is where most of the embodied carbon in a door is lost. Dfendoor and Shieldoor and PVC post-formed meaning they are highly durable with strong impact resistance, extending service life across the building's lifecycle.
Full EPD (Environmental Product Declarations) are available for our Dfendoor and Shieldoor ranges.
What is the cost difference?
Because Dfendoor and Assuredoor use different facings, there's a natural difference in price — Dfendoor's PVC post-formed facing uses more robust materials than Assuredoor's laminate or veneer, so it typically sits at a higher price point. But the two aren't competing on cost; they're designed for different locations. It comes down to specifying the right door for the right place: Assuredoor is an excellent, cost-effective choice for lower-impact areas such as offices, consultation rooms and storage, while Dfendoor's added durability earns its cost in high-traffic clinical spaces where doors take constant impact. In those demanding areas, a more durable doorset tends to last longer and need fewer repairs and replacements, which can save money across its lifecycle. Choosing based on the location, rather than the initial outlay, is usually what delivers the best long-term value.
