Floor Joists
Our FLOOR products
Floor Joists
Our floor products are metal web joists. These joists are made from an upper and lower timber member, connected by a steel web, this element is what provides the joists strength. This combination of timber and metal webs results in a strong and light-weight joist solution.
The crowning glory of the metal web joist is the space the open webs creating a natural service void. No other product on the market offers this unique feature providing a void within the floor zone. Cables, pipes, waste pipes, ducting and more can be threaded through within the floor zone with no requirement for cutting, notching or drilling. The benefit of this is saving time which vastly reduces the labour time on site, resulting in lower labour costs and a faster build programme.
Made to measure floor joists
Our floor joists are a bespoke designed item. This means our designers ensure the floor joists are manufactured to the exact sizes required. Combine this with our site measuring service, and you can be assured our floor joists will drop effortlessly into place, giving you peace of mind.
Also, our CAD and laser-guided saw output and manufacturing jig ensures accuracy on every single joist that we manufacture.
Read more about our cutting edge laser-guided technology on our blog.
Floor performance
When it comes to engineered products, there are design codes or standards that all products must meet. With floor joists, the most relevant standard to performance to is the maximum amount of deflection (bend) the floor is allowed.
For a floor to conform with the design standard, the floor joists must not deflect more than 14mm. If the deflection is too great you can feel it as you walk across a floor, this is the bounce that you feel under your feet. So, the bouncier the floor, the closer to the upper deflection limit the joists will be.
Many manufacturers will opt to design as close to this limit as possible, as this allows them to use shallow and/or narrower joists. This means they can use less material in the joist which means a cheaper product overall, allowing them to offer eye-catchingly low prices.
Here at ETS, we believe that the overall lifetime performance of the product and its quality is more critical than merely generating sales. Quite simply, the lower the deflection, the firmer the floor feels, and the floor ‘bounce’ is reduced.
Our designers will always ask you about the level of deflection you require and they will clearly label on the drawing what the degree of deflection is within our design. Wherever possible, and unless advised otherwise, we will always ‘over-engineer’ our floor joists to provide a higher quality product.
Aren’t metal web floor joists expensive?
“Surely they’re much more expensive than the I-beams, aren’t they?” This is a very common misconception of metal web joists when compared to alternative products, such as I-beams.
It’s a question we get asked daily.
Metal web joists, due to their construction, are far stronger than I-beams or solid timber floors. Therefore, they either span the same distance in a shallower depth or span distances which other products simply couldn’t achieve. What this ultimately boils down is:
- Smaller depth joists, which can be important when floor to ceiling heights are at a premium, or when building an extension and existing floor depths need to match to avoid a step in the ceiling, without compromising on floor deflection.
- Joists that clear spans without the need for internal supports, this means there is no need for internal load-bearing walls or steel beams. Eliminating these walls and or steel beams can have a drastically reduce the overall build costs as it removes the associated labour, groundworks and materials required.
So, if you’re looking at simple linear metre costs then please be aware of all these factors. Metal web joist are very cost-effective, and if you’re not convinced, then please contact our team on 01952 771170, email us at sales@etstrusses.co.uk or use the request a quote page. They are more than happy to talk you through all aspects of metal web joists.

Free Quote
UK WIDE