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This is the archive of the Tony's Comment column for 2008/9.
Please find below each article posted in 2008/9.
Fire Bolt Caps—A Solution to a Sticky Problem
10-11-08
It could be argued that the problem of connections between structures is not very clear when it comes to fire protection. Does the British Standard fire test only apply to a full length of beam without any connections to columns? What happens to the connection and how is it tested? It appears that there is no specific British Standard for fire testing connections. So what is the solution? Do we treat the bolts and nuts in the same way as the rest of the steel beam or column i.e. thin film intumescent paint the connections? Is it fair to say this is the current thinking and could it be argued quite a reasonable policy? Except; we blast and prime the steel generally to SA 21/2. Do we blast and prime the nuts and bolts? The bolts may be galvanised. We degrease steel sections which have been galvanised then we acid etch and prime them. Do we degrease, acid etch and prime the galvanised bolts? I don’t know. But we should. After all, the connections, nut and bolts, are all part of the same structure.
It’s all down to adhesion, stick-ability. If a surface, about to take a primary coating, is not prepared correctly the material may not stick to it. This is no different for steel about to take intumescent paint—it relies on the primer underneath to be fully bonded with the steel, to the nuts and bolts which may be coated. Unfortunately, there is often mill oil on top of the natural or galvanised bolt/nut. It is quite clear then that the adhesion of an application of fire protection is not going to be as good or last as long as a surface that has been prepared correctly.
For those who do prepare the surfaces correctly, the cost of doing so is all too evident when the man hours on site are counted for this operation.
What’s required is a solution that does not depend on the preparation of the nut and bolt. What’s required is a simple clip-on device that has been tested to perform as required in a fire for up to 2 hours. Interact Fire Solutions’ Fire Bolt Cap has been tested and shown in some cases to out-perform the equivalent intumescent coating to the connections. The bolt cap can be put on with a simple knock on the head of the cap. For security reasons they are very difficult to remove without evidence. They take about 5 seconds each to install. They do not rely on any correct preparation to the bolt or nut. So long as the dimensions of the connection meet the British Standard for the bolts and nuts, then the Fire Bolt Cap will be fit for purpose at a cost effective and competitive price.
Interact has successfully secured the distribution rights to market and sell this very effective fire protection and in doing so has worked very closely with the manufacturer to provide a very cost effective solution.
More Information on Fire Bolt Caps
Uncertainty over fire protection to suspended rods
25-09-08
The conventional way of building a steel structure, from the base upwards, is increasingly being challenged and the use of suspension rods which hold up a suspended floor is becoming more and more common.
The advantage of a suspended floor is that it will leave a completely uninterrupted view without the need for structural columns which would otherwise obscure that view. Generally the suspended floor can be used as a mezzanine floor and is popular in penthouses.
recent Interact project.
The practice has now gone one step further with the recent design of The Edge building in Dubai where, apart from the main structural supports, all the floors will be suspended from the top of this tall, iconic building. As in the UK, British Standards (BS476 part 20 and 21) are used in Dubai as validation for fire protection to structural steel. Other standards are acceptable in the region and can get Civil Defence Approval, a prerequisite to being specified.
But there is a problem
The problem is that there are no standardised fire tests for fire protection to suspended rods either in solid or hollow sections. The Association of Specialist Fire Protection (ASFP) has not yet provided any guidance on the application, but is known to be considering issues such as:
- Is it necessary to test a structure under suspended load when there is adequate test data for compressed load?
- What load criterion is applied to suspended rods?
- Are the dynamics of tension the same as the dynamics of compression?
- Should an indicative, unloaded test suffice?
- In the absence of a standard should one be developed to meet this increasing demand of fire safety for suspended floors?
Hopefully, a formal position on the appropriate guidance will emerge sooner rather than later. Until then, the ASFP has no formal position and guidance is only available from structural consulting engineers with appropriate experience of the problems. The scope of any test data will need careful consideration.
Interact Fire Solutions, by the very nature of its market segment, comes across suspended rod enquiries on a regular basis. The Edge building in Dubai is just one of a number of enquiries received from London and in other parts of the world. Our experience is that consultants and fire engineers do want a loaded test.
Why not use traditional fire protection methods?
The use of thin film intumescent or any sprayed application for suspended rods is challenging when it comes to aesthetics. Yet the whole concept of the architectural design is based on “thin and slender” structures. How disappointed is the designer going to be if a 60mm rod ends up at two or three time that diameter because there is no other way to fire protect and achieve the aesthetics at the same time? The option of secondary cladding might appear to be the only option available.
image)in an Interact Fire project
Interact Fire Solutions is a member of the ASFP and is lobbying strongly for a loaded test to be agreed. This is not only because we believe we have a solution but more importantly, our clients demand confirmation of the fire performance under load.
Interact’s Interactive Casings, which are made from cast epoxy intumescent, can provide the required fire protection with a minimum increase in rod diameter while at the same time achieving an excellent aesthetic finish to iconic and state of the art architecture. Interact will continue to lobby for a loaded test as we believe in having proof of the full integrity of our systems to meet the demands of construction.
Welcome to Interact’s new website
21-8-8
I hope that you will be able to see an improvement in both the content and structure which will allow you to browse more effectively. One of the major improvements is the “Contact You” tab on the left which provides a quick response. Just fill in your name and contact details and we will respond on the same day by either phoning or emailing you.
Over the past few months we have been working with Design Jazz to bring the site on line. There are a good number of projects and photos on the website which will be upgraded on a regular basis. For instance we have professional photographers visiting two major projects in Newcastle. In the next few weeks we hope to have pictures of The Hancock Museum, which was an internal high decoration project in the newly refurbish exhibition hall and the Eldon Square Shopping Centre where ten external columns are featured and highlighted at night with down lighters for a great aesthetic appearance in one of the busiest night spots in Newcastle.
You will also see that our product portfolio has expanded to incorporate secondary cladding and our special hybrid castings for universal columns. In addition Interact have now secured the agency for bolt cap fire protection. The website explains the advantages of all our products in an ever increasing demand for real quality and integrity in fire protection.
I hope you enjoy our new website.