Ok so ive been asked to clad a ropey old mobile classroom at a school and i’ve suggested using softwood featheredge (treated) as is reasonably priced to buy and fix. Anyone know if spread of fire is a consideration and would make it unsuitable for use in this case? I’m not after just an opinion, i need to know for sure.

It seems to me the answer is no as for starters the outside is clad in ply already with a decorative coating. How many summer houses, eco lodges etc are similarly clad or roof dormers clad in pvc. I need a definitive answer as I dont want to fit it and then someone come and wag they’re finger and tell me to remove it! I cant see how contacting building control would help as its a temporary structure. Maybe im worrying about nothing..

Anyone know for sure?

The school will have H&S and architectural consultants, either LA or a private company depending on the school. What do they advise?

As timba says, if you don’t know, get the proper answer from the owners or their expert.

Have a read of this, but more importantly, talk to a professional who is familiar with the regs, possibly whomever carries out the fire risk assessments

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/276389/buildingbulletin100_onlineversion.pdf

Yeah i’ll pass it back to the school and get a definitive yea or nay in writing from them before proceeding.

But what would building control advise? Assuming that would be best practice .

We cut a load of cladding for someone at work, but he can’t use it on one side as it is, due to having a neighbour boundary within x metres. There are fire retardant treatments available, but block work is cheaper. TRADA are a good source of information on stuff like this .

Another consideration is potential arson – a good proportion takes place on school premises. What input on this do the schools insurers have?

Thanks Grunka thats really helpful. Reading it section 7.2.4 says that for single storey buildings more than  1.0m away from the boundary there is no requirement and for more than one storey up to 10m above ground timber cladding of minimum thickness 9mm is sufficient. That reassures me but even so I will still ask the school to get the powers that be to still give it the go ahead.

The effect on nearby buildings, on the same site has to be considered too. (I.e. fire load)

Zurich municipal for one recommends that timber cladding is not used at ground floor level, and if it is, then it is fixed only to a solid substrate like blockwork (See their school buildings design guide)

Rather than wood you could clad using Marley Cedral – no fire issues there.