roof joist

hi all in a flat roof made of 2 x 10 with no weight on top other than the ply wood and felt what is the mximum distance with out steels to stop it from saging. thanks

It depends on several factors. Your local building inspector division should be able to supply a "span table" for acceptable spans vs load in your country. As a point of interest, you can span a farther distance with a closer layout. Ontario Building Code with snow load calculated in on a building of not more then 15 feet wide, 2 X 10 on a 12" layout, 17.72' (17' 9 ") is the recommended span. Same town same 2 X 10 using a 24" layout the recommended span is 12.53' (12'-6"). In Cucamonga, Calofornia 2 x 10 on a 12" layout you can span 23’-9”. This information is all given as a means of example to you, Joey, so that maybe you will be able to understand why it is important to check with your local/regional building inspection department to get a span chart to keep you and yours safe and able to comply as needed. Hope this helps, Brien

thank you ill pop down and see if i can get a span chart. dont want the roof falling in on me.