suspended loft floor

[simonnev]

Hi all.
I posted a query some months back about the loft conversion that I had at my home.

However I had too get the floor changed by dropping all the ceilings etc to fit the new floor joists for the loft running from steel I beams at each end (calcs done via structural engineer)
Due to it coming to light that the original job was bad mainly the floor and how it was suspended.

But the first job was carried out by a family member and has caused many arguments of who is right or wrong.

Please could you pass comment good or bad to let me know if the original job was safe to begin with.

The floor was made up from 5 by 2” joists not sure on the centres think it was 450 but I will check, the span was in total 14ft with aprox resting (not fully on a party wall packed with old piece’s of wood) leaving a full span of 10 ft. there was no noggins fitted . Is this of correct size for that span?


Now this was suspended via 2by3 inch screwed into the roof rafters at each end behind the purling. Then screwed into the 5by2. Is this correct



The house ia approx 1910 and the rafters cannot by more than 4by3 again I need to measure them to be fully sure.
Thanks for your time Simon

 

[PaulJR]

The floor you describe is not up to Building Reg's standard, and therefore is not acceptable as a floor of a room.

BUT

If it was only intended for light storage it is difficult to say categorically that it's wrong.

HOWEVER

A few pointers:
Hanging the floor off the rafters increases the load on the existing roof, which DOES require approval, and would require calc's etc.
5"x2" timbers cannot span 10' at flooring loads, you would need something like 6"x2" as a minimum, noggins are required at 2.0m centres - or mid span in this case.
A few screws will not carry the loads involved, the screws may be strong enough, but they will rip out of the timber.

Hope this helps

 

[simonnev]

Many thanks for the reply pauljr

you have confirmed what i expected

If i would of known that the floor would be suspended from the rafters i would not of gone through with it and defo got a second opinion.
whats worse is that my kids where up there and also adults have used the rooms..
I left trust in someone who i thought could trust especiallly the bloody floor, seems to be a very critical point to me and also that the span for the 5*2 was too great for any load ie people furniture even the laminate floor it all adds up..