Expert: Dave Johnson - 2/6/2008

Question
i am planning on building over the kitchen and liv room 24x32.i have to strip all the roof etc off.can i reuse the rafters? can i build on the 2x8 ceiling joist.there is a 18" footing under the first floor.the structure should be fine.any extra tips? thank you brett

Answer
Hi Brett,
Yes if there is no structural damage the rafters can be re-used.

If the joists are spanning 12' and are 16" o.c. , they may be okay for light use, but it would be better if you sister every other one with another one.
If they are spanning 16' and are 16" o.c. , you need to sister EVERY one.
Make sure you use bridging (metal or wood criss crossed between   joists) this will help eliminate "bounce".
I'm assuming you don't have a stairway in the existing building...when you frame the new opening, all framing around it need to be double.
Best of luck...and mail me if you need more.
Dave