floor joists in loft

[derek420_00]

hi there
i am planning to convert my loft space in a couple of years time but i want to start doing one or two jobs now .
to start with i have been told i will need to put bigger joists in , can these be put in alongside the existing joists and do they have to be the same hight or do they have to be a little higher also i have heard people mention chicken wire ?? what is the purpose of this ? , hope im not being a pain im new to this , regards ,derek

 

[masona]

Your best bet is to get a drawing plan made up then you will know the size of the joists and do what you can. I think the drawing plan are valid within 5 yrs, if you don't start the work within 5 yrs then you can just updated it. The joists size is depends on the span

 

[alfiembra]

An old rule of thumb to calculate the depth of timber joists is take the span in feet divide it by two and add two inches. So for example if you had a 3 metre or 10 foot span, divide by 2 gives you 5 add 2 giving you 7 inches depth so 7x2 @ 450 centres. This is for floor loading for roofs it's just the same except add 1 inch.

HTH

Alan