A school has an outdoor wooden shelter/fixture which is very old and needs to be removed from site before it causes some damage.  A parent is willing to dismantle it and take it from the site?  Obviously the school does not want to be liable should anything happen whilst they are doing this as it is a heavy structure.

Would tge school be able to put something in writing to state that it is at the parents own risk and the school would not be responsible for any injuries caused  in removing it?  Would this be accepted if they did suffer injury?

Thanks

it is of course demolition and subject to CDM and i think notification  

No such thing as a legally binding disclaimer I'm afraid!

I'm guessing this 'building' is no more than a wooden shelter of some sort, just a few wooden posts and a roof, maybe some seating?

Is the parent thinking it will make good firewood? It won't if it is treated timber, it contains copper compounds and must not be burnt or it will give off toxic fumes, it needs to be disposed of properly. 

As you say, now you have identified it as dangerous you really must take action.

Why not send an APB (all parents bulletin) out, maybe there is a parent who runs a building firm and might offer to do it for free? You will still need to be compliant but they will have everything in place and probably do it in an hour.

There is absolutely no reason in principle why a parent or group of parents should not do this.

But as others have said - you cannot sign away your legal obligations by a disclaimer. 

The school needs to make sure that they know what they are doing - that doesnt meant that they need a CSCS card or have any formal training whatsoever. If it's a simple task they need simple skills, if its a complext task they need complex skills. "competent" doesnt mean "expert". If its a simple task they should be able to convince you that it can be done safely.

They won't have their own insurance so your school insurance policy should cover parents undertaking tasks on a voluntary basis - but it's worth checking that this activity would be covered.

The site manager / caretaker should talk through with the parents how they intend to do the task and agree how they are going to do it, and when. The site manager should be comfortable that the parents have got a plan that will work and the people (and equipment) they need to do it. It would be sensible to have that written down - an exchange of emails is a good way of doing that. You'll want to know who is "in charge" - just one person! It could be as simple as "if two of us push hard enough on one side it will collapse perfectly safely" or it could be "its made of screwed together 8*4 ply sheets and we'll take those off one by one by unscrewing them".

You will also want to know how they intend to dispose of the bits of the structure afterwards - if they are going to take it to a tip you need to consider that this could be "trade waste".

You will need to tell them anyting you know about its construction or condition - for example "that roof is bloody heavy - you'll need to get that off first" or "one of the legs is really weak - it's rotten all the way through" .... or "the roof isn't strong enough to stand on" ... or "when they knocked the old school down they dumped all the construction debris in a heap and we built the shed on top of it" (in which case you might start to think about asbestos debris in the ground). Again, record that you have done that by an exchange of emails.

You should retain the right to stop the work - that means that someone from the school should be on site when teh task is carried out and be prepared to intervene if things start to look unsafe. 

You should have a backup plan if, for example the structure ends up only half dismantled by monday morning when teh children are back on site.

Lets have common sense solutions to simple problems.