By Robyn Stafford-Bush on 13 October 2020
When siFramo was introduced 14 years ago, Building Services was not exactly what Sikla had in mind as a market. Nevertheless, the product system has succeeded in such projects. This article is to explain why. Since the Building Services industry is the only industry that finds siFramo occasionally expensive, this is also a reminder of where and when the product should be used or, to address the cost argument, where it should rather not be used.
I have put the applications where siFramo offers a benefit in HVAC, Plumbing and Electrical installation projects in two categories:
So let us get started:
Building Services projects that may benefit from siFramo Modular Steel
- Plant Rooms and Energy Centres, in particular those without a solid ceiling structure to fix steel to
- Multi-service corridors or tunnels
- Utility risers with large cross section areas
- Maintenance access platforms and walkways
Above: siFramo Goal Post Frames in Plant Rooms and Multi-Service Corridors
The common denominator of the above is that a design without a heavy-duty modular steel system like siFramo would otherwise require welded steel solutions. It cannot be stated often enough but: where a strong (back-to-back) strut channel can be used, it should be used! Whenever siFramo was considered too expensive in building services we have observed just two reasons for it, both being connected with the overall problem of ‘overdesign’ in one way or another:
- The load capacity requirements could have been addressed with a strong strut channel, for example single direction rather than multiple direction load
- A comparison was made based on the size of the steel section rather than the strength of the frame
What is it then that makes siFramo attractive for those 4 main application areas?
On the structural side it is its column- and its multidirectional strength, derived not only from the box geometry but from the connection design. Then on the practical side it is the flexibility to adapt to unforeseen obstacles such as building tolerances, generously used by the civil contractor, or last-minute design amendments.
In times of light-weight structures and drywalls it is after all the lack of concrete and brickwork as an absorber of weight and forces, that siFramo can compensate your installation team for, making their job easier.
siFramo base frames for maintenance access (left) and service riser basement anchor (right)
To sum it up: if you thought of siFramo as an alternative to your P5001 back to back channel you might be disappointed by both its buying price and the single load performance over a long span. So please see it as an alternative to your sturdy welded steel frames from double-flanged beam, box section or Parallel Flange Channel (PFC) and you will be positively surprised in many ways.
Circumstances in Building Services projects that may benefit from siFramo Modular Steel
- Offsite design and fabrication of services required or desired
- Seismic calculation of supports structures specified
- Primary building structure inadequate to house services’ load
- Fire rating of certain service supports
For all the above reasons siFramo has repetitively been used.
Its 3-dimensional design that makes a junction of 4 sections as easy to assemble as a junction of 2 sections, has made siFramo a widely acknowledged alternative to cumbersome and heavy off-site frames. Their structural job is usually over after just a couple of hours transport from workshop to site but, their significant weight will stay inside the building shell for the next 50 years. Moreover, siFramo’s connection method of using automotive self-forming screws removes the requirement for additional vibration- and transportation safety measures such as nylon-nuts.
When it comes to seismic, the requirements of my personal business development area New Zealand have led to a regular use of the system in many areas that would not be expected to be installed with siFramo elsewhere in the world.
Here it is important to be aware that the prevailing light-weight structure, used to support pipes and cables, the generic Unistrut, is an ‘open C structure’ which means that it is strong in one direction only. An earthquake’s implication however are seismic forces that affect a structure from potentially all directions simultaneously. [Learn more here about Sikla'Seismic Guidelines]
Therefore, Unistrut frames must be beefed up with bracings, often several ones per frame, and retrofitted. Using siFramo may then save installation time, and space for bracings, to a degree that the higher price per frame-metre is more than set off commercially. With our F80/30 size steel box section, we even offer a structure that occupies less space than the 41/41 P1000 whilst taking a multiple of the load in all directions and without additional bracing.
The opportunities to use siFramo when there is no solid wall or slab nearby have already been mentioned, so what is left is fire-rating as a reason to use the product:
In a nutshell, fire-rating building services support structures means that the ultimate collapse of a support structure under the extreme heat of a fire will be delayed by using stronger structures than necessary in order to protect escape routes for a minimum time. Being a thin gauge metal structure, siFramo can in this respect not substitute a steel beam with a 10 mm thick flange, this can only work vice versa. However, using siFramo as the fire-rated structure where there are otherwise 41/21 P3300 supports or Gripple-style cable suspensions, makes technical and economic sense. [Learn more here about Sikla Fire Protection Guidelines]
So how Building Services Engineering benefit from siFramo?
A structural benefit of multi-directional strength and surprising flexibility of frame configurations and installation are major benefits of the system. This flexibility idea goes even further if you think about the utility of siFramo in such a wide range of structures where it can be applied, as shown above. Were you one of those thinking about the cost argument? If this crossed your mind previously, hopefully you can now put it aside, when considering these overall benefits of the siFramo, designed for Building Services applications.
Written by Robyn Stafford-Bush
Business Development Manager (New Zealand)