Fire Stopping

[lingmoor]

Hi all

A hospital has just been found to have IT cabling installed without any fire stopping! This has been going on for some time which is pretty worrying to say the least.

 IT cables that pass through compartments/sub-compartments  should obviously be fire stopped. My question is what type of fire stopping material should be used?

looking ad ADB and the 'Red Book' it mentions 'proprietry seals'.... can someone tell me what is the difference between proprietry seals and intumescent mastic

I would imagine that a ball park figure would be mastic is ok for say penetrations of up to 100mm x 100mm but anything more than that should have an appropriate cavity barrier.

Also what is the opinion of the forum of third party accrediation such as FIRAS?

Also, also ... unless I'm reading it wrong the mastic etc itself does not have BS number ...it is the finished fire stopped partition that should be made good to it's original BS 476 Part 20...is this right?

cheers

[Mike Buckley]

Hi Lingmoor,

Not as simple as it sounds.

You need to have a look at the ASFP PU data sheet 1. This is from the Association of Specialist Fire Protection talking about 'fire proof' polyurethane foams.

The other issue I have come across with computer cables is that some foams will actually attack the insulation around the cables in particular the fibre optics and you will need to review the chemical nature of the foam to prevent this happening.

[Kelsall]

Use that foam stuff everyone else does!  

What you need to do is assure that the product used has been tested in that situation and seek some assurance of competence of the contractor you have chosen. FIRAS is one of several third party schemes that gives you assurance and has built in arbitration if there are any issues. Many NHS contracts are building in third party inspection as an added quality check. This can be done by the CB as part of the ongoing audit process or can be from an independent inspection body on a sample only basis.

[Owain]

The other issue I have come across with computer cables is that some foams will actually attack the insulation around the cables in particular the fibre optics and you will need to review the chemical nature of the foam to prevent this happening.

I think this can also be a problem with PVC insulated mains cables.

[lingmoor]

Thanks for your replies

[jayjay]

Be very careful when considering  the foam sprays they have very limited application.
If the breachs are numerous or large openings recommend a specialist.

[kurnal]

I usually avoid expanding foam like the plague but I Came across this one yesterday, still awaiting a copy of the test certs but compared to many such products it appears promising for limited application 100MM X 100MM up to 300mm x 300mm and a claimed 2 hours fire resistance

http://www.hilti.co.uk/holuk/page/module/techlib/teli_results.jsf?lang=en&nodeId=-127215&selectedOid=-455237

Check it out to your own satisfaction or otherwise, I am still not convinced but potentially  looks more promising than most .....

[AnthonyB]

The key difference is the Hilti product is not an expanding PU foam in the same vein as the aerosol can foam so often used - whilst it is described as a foam that expands it appears more complex being a 2-pack type product.

It also has more specific application instructions and clearly still has to be used in conjunction with other intumescent products- the traditional foam just gets sprayed in on it'sown randomly (or so it seems).

I always urge the use of a third party accredited specialist as I've seen far too many bodge ups by general builders/joiners etc, as  much due to ignorance as much as corner cutting

[Kelsall]

I have never seen a foam tested in anything but a small linear gap. If they can't give you a full test report that has a clear description of the test, then it shouldn't be used as a 'fire filler'. Foam has very limited tested applications.

[kurnal]

I have never seen a foam tested in anything but a small linear gap. If they can't give you a full test report that has a clear description of the test, then it shouldn't be used as a 'fire filler'. Foam has very limited tested applications.

I have now received test certificates for the Hilti CP660. A test rig  comprising 8 apertures each 400mm square set in a plasterboard stud wall with a full range of service penetrations was subject to BS476-20 test and all were satisfactory for integrity, the test was ceased at 134 minutes. For insulation two samples failed insulation crieria at 77 minutes, the remainder withstood the full 134 minutes. There are also details of tests in the horizontal plane. So this appears to be a foam that can be relied on if correctly applied.

I will be happy to share more details by pm. Oh by the way Kelsall the test station was that outfit over at Warrington.

[lingmoor]

thanks for all the replies tis appreciated

what is everyones view of putting 'labels' on the area that is firestopped? ie date/name of contractor, and that the firestopping has reinstated the compartment/subcompartment to 476-20...or would just a permit to work suffice that has all that info on

cheers

[Fishy]

The outfit that I work for normally insists that all new penetration seals are labelled with the Contractor's name & a unique reference number.  Simplifies verification upon hand-over (you know that somebody competent installed it) & it eases inspection & maintenance.  This has been done for a few years now, & it really helps when maintaining passive fire protection, on a large Estate.

[lingmoor]

cheers for your reply Fishy

[jayjay]

Further to Fishys comments some companies are in addition to labelling the fire stopping  are making a photographic record of every area fire stopped.