Suspended ceiling Load

[Struggling100]

I own a residential property ( circa 1900 ) and have removed the old lath and plaster ceiling in one of the bedrooms on the first floor ( the first of 6 rooms to do). This ceiling is to be replaced with a suspended plasterboard ceiling, suspended off of the old ceiling joists which are 100mm x 50mm ( 4 be 2 ), 4 metres long and spaced at 370mm intervals.

The suspended ceiling may well be heavier than the original lath and plaster because of the need to double board in some rooms ( fire seal ), as we have a loft conversion on the top floor above some of the rooms.

I have an esimate of the anticipated max weight per sq metre of the new ceiling ( 25kg /sqm for double boarded rooms) and am after a structual calculation that will tell me the max load that the old joists will safely support.

My feeling is that this is a fairly simple calc and was wondering of anyone could recommend a good Structual Calculation book that I could take a look at.

Many Thanks

 

[denso13]

4m long? Is that the clear span, unsupported? Tables I have show 4 x 2 supporting that load should be maximum 2m span, give or take, depending on a couple of factors.

 

[Struggling100]

Thanks for your response denso.

Yes, the Full length of the joists is approx 4m between the inside edges of supporting walls at each end. If I don't double board the ceiling, the load will be about 15Kg/m2, will the joists support this weight OK?. Any idea where I can get a copy of your tables!?

 

[denso13]

Put an address in your profile and i'll send you some info

 

[Struggling100]

Done that, check out the AIM address in my profile. Thanks very much denso.

 

[Struggling100]

Denso, Thanks for the comprehensive info, very much appreciated - I will start to wade through this weekend.
Thanks again