I had a 2-story home build in 2004. In my attic I have an area approx. 16 ft wide, knee wall to knee wall and 36 ft long. The second floor is 32 foot wide by 38 foot long. The attic is accessible through attic pull down stairs. The joists in the attic floor, or 2nd floor ceiling is 2x6 16" oc and is floored with 1/2" osb for storage only. It feels very sturdy. I want to finish the attic into one large play room for kids. To start with is the existing 2x6 16" oc sufficient for live loads. If not should I sister and what size. Is this a DIY job, joists and new 3/4" flooring. I want to hardwood the floor upon completion. I do plan on having stairs installed later. I have enough room to get the materials up to the attic in full sheets. The span for the floor will be approx. 16 ft less framing and finished walls. Also there are walls under on the second floor as the hall runs directly under the 16 ft span with walls perpendicular into bedrooms under span. The only span which doesn't have walls under is in the master bedroom, far end. This room is 16 ft from end of house with span of 19 ft under attic, and above my stairs is also an open span of 10 ft. Any suggestions? Thanks

You have a couple of issues there which should be handled by a design professional, who can visit the house and see all conditions which may affect the framing. I can tell you that the 2x6 ceiling joists will not likely be adequate to function as floor joists. I can also tell you that the 19-foot span will require spcial attention. Then, if you are going to install future stairs, you should frame the opening for them now. The design professional you retain will also help you with the design for that.

The thought of putting the stairs in later scares the heck out of me, especially if this is going to be a kids room. Not only is it against code, but you wouldn't be able to live with yourself if there was a fire and there was only a pull down ladder for the kids to get out of. I really hope you are in a code enforced area.

Sorry for the confusion. At first it would still only be used for storage, just very nice and heated storage then when I am ready to use as a kids room in a couple of years from now then put the stairs in. My wife is expecting now and we are wanting a playroom in 2-3 years. I have contacted the original contractor and he is interested in finishing the attic this winter during the slow season. After speaking with him we would start with the stairs then proceed with the rest. He suggested sistering the 2x6 joist with maybe 2x8 but would decide when he re-visited the site later this fall. Thanks for all the help...rj

Be careful. The 19-foot span can never be accomplished with 2x8's, even at 12 inch centers. Get yourself some professional help.