BS EN1991-1-1 & BSEN1991-1-6 Sould the designer include the construction and Maintenance Loads

[Whilber]

Hi I have a large new build 2 storey house project. There is a flat roof around the perimeter of house at ground floor ceiling level. The flat roof has to support the scaffold to access the main pitched roof for construction stage and future maintenance. It is not easy/possible to transmit the scaffold loads to ground other than through the flat roof.

The designer is the timber frame supplier and was aware that a scaffold needs to go on the flat roof for their construction phase and for future maintenance ie changing pv panels or roofing.

My question is should the designer include the scaffold weight in establishing the loads as part of the flat roof design? Otherwise the roof will need propping for construction phase and for any future maintenance. Propping for maintence will be very diruptance to the inside of the house and not ideal.

My interpretation of BS EN1991-1-1 Ref6.3.4.2 Values of actions, requires the designer to consider All loads that the building will be subject to during its ordinary life this includes construction and maintenance. Construction Loads are further defined ref BS EN1991-1-6 Actions during execution which includes scaffolding as defined. I believe one of the underlying principles of BS EN1991 was to get Designers to consider the whole project not just parts of it and therefore can't ignore construction and maintence.

Does anyone have a view on this? Thank you.

 

[GeorgeTheCivilEngineer]

You've answered your own question since you said:

"The designer is ... aware that a scaffold needs to go on the flat roof for their construction phase and for future maintenance"

If they were aware that absolutely they should allow for it.

If they weren't aware then I'd tend to say no. Construction can be carried out in lots of different ways so it's unreasonable to expect them to allow for every option in constructing the building. A requirement like that would need the contractor engaged and telling them what they need. Indeed, I'd generally expect to finish the highest roof first and work downwards!

Ditto with maintenance - they need to be told you want scaffold rather than a cherry picker or roof hatch. Use of scaffold to reach roofs for maintenance purposes is more unusual.

 

[Whilber]

Thanks George.

Re maintenance, access around building is narrow c.1.0m and therefore difficult for cherry picker to access the rear and 2 sides (most cherry picker are around 1.4m wide).

The main maintenance being considered was for PV on the 3nr pitched roofs and that is prefereable from scaffold over cherry picker as they need a platform to load on and off.

Many thanks for you help.

 

[GeorgeTheCivilEngineer]

I missed that you said designer and contractor are in the same firm. So the balance does shift back towards 'they should know how it's going to be built'!