New floor in industrial unit

[RJM1234]

Hi all,

I’m about to start on a project which involves installing a first floor into a modern commercial industrial unit and am planning to do a lot of the work myself.

I'm not a builder but have good overall skills and feel confident that I could physically do the work to a good standard.


I'm guessing that I need to get some structural calculations done by someone to spec up joist sizes etc, but had a couple of questions...

Firstly how much is a structural engineer likely to charge me for the work and what will he tell me?

and secondly - as its a modern building (6 years) do I need the engineer at all for calculations? It doesn't seem particularly complicated - everything straight and true. Does anyone have advise on this from this forum as far as joist sizes go?? Posi / Easi or traditional timber?

The new floor will span the 6m width of the unit (concrete block wall on either side) and extend about 7.5m into the unit. Obviously I need to spec for an office load - I'm likely to use ledger boards bolted into the wall on both sides, although I have the option for retro fitting some joist hangers (built in). Any thoughts...or should I go home now?

 

[freddiemercurystwin]

Joists for a 6m span will be mahoosive and will likely make it more economical to use an alternative. You doing this through Building Control?

 

[RJM1234]

I'm guessing its notifiable, so yes

I've already got a number of partitions and some blockwork on the ground floor, so looking to build the floor over existing structure. If I use the timber frame of partitions and the blockwork to support the joists as well as hanging them on hangers I guess I can use smaller joists. My max span this way will be no more than 4m.

Am I already out of my depth?

 

[freddiemercurystwin]

That's fine, provided the existing floor can take the additional loads. How thick is the slab? That's what your Inspector is gonna ask! What are the walls, any chance of a photo or sketch to clarify things? You may also be into fire regs, escape routes, escape lighting etc. BC involvement is essential. An engineer could be say £200-1000. Depends how much they have to do and if they're cheap or expensive! It may sound obvious but I've just had 3 quotes for some work, £200, £350 & £850. The £850 was from a one man band, the others were firms.

 

[RJM1234]

Thanks. So <£1k for engineer - doesn't seem so bad if it means I get it right.

Here's a quick (and I do mean quick) plan.

Untitled

• RJM1234
• 7 Nov 2013
• 1

Its a typical 2 storey metal frame industrial unit with full height single skin blockwork separating us from adjoining units. There's a toilet block made from concrete blocks as shown and we've installed serveral partitions at ground level to 2.4m and put in a suspended ceiling.

The green box indicates the extent of the proposed new floor[/img]

Not sure how thick slab is, but they've done a mezzanine next door, so guess its ok.