What’s the correct flooring depth or product for loft extension??

[nmh]

Just done a major renovation throughout the house but the flooring laid for the top (loft) floor is creaky when you walk over them and seem to spring more than I’d like. 

 

See the pictures attached. Is this ply board the builder has put down? It looks @12mm to me. 

 

Rest of house is ok because he’s put down 18mm chipboard. We’re carpeting throughout. 

 

Any thoughts much appreciated. Thx 

[Temp]

Whatever it is it's crap. Looks like 2nd hand/used shuttering plywood. Should be at least 18mm thick but I prefer 21mm.

 

Check the joists are the right dimensions for the span first.

 

[nmh]

Thanks for this. I’ll get on it. It’s like a trampoline up there!

[Conor]

22 hours ago, nmh said:

Thanks for this. I’ll get on it. It’s like a trampoline up there!

Is this a full, proper loft conversion? Habitable room? Reason I ask is the original joists may not be up to the job and thicker floor boards might not make a difference.

[nmh]

Proper loft conversion. Think the joists are solid. 

[kandgmitchell]

That's got to be 2nd hand surely - it looks really rough! "Think the joists are solid"?? Presumably you have some professional drawings of this conversion. If it were me I'd be looking to see what was designed and approved has actually been provided.

[DevilDamo]

What does the BCO say?