flooring options for new laundry room

[robG]

I've got a 10x6 back porch that I'm converting to an enclosed laundry room and have a question about the flooring. Currently, the surface of the porch consists of 3/4" flagstones on top of a concrete base. There is about a two-inch step down from the main house onto the porch.

Should I remove the flagstones or leave them? There are no cracks and it's very solid. However, as it was constructed as an outdoor porch, it has a slight gradation away from the main stucture. Do I need to level this before framing the addition?

If I leave them in place, can or should I layer concrete or some other compund over the flagstones. I would think that if I used this approach that I should remove the flagstones - doable but no easy chore.

Also, I've considered widening the dimensions from 10x6 to 12x6 which would require adding a 2x6 section to the existing porch. Any ideas for the best approach to handle this task?

Thanks for the help.

[Wgoodrich]

If it were me I would use 2x4 treated floor joists [no free spanning all laying on solid base]. I would frame a 2x4 floor joist area with a band board wrapping the joists to make a solid flooring. Then I would anchor that floor framing to the concrete ignoring the flag stone. This would make about a 1" step up that you could create a ramp or allow for a step up. Then use 3/4 plywood as a sub floor / flooring then finish as you like.

If you wish to add the 2' to your square foot of flooring then you can do what is called a cantelever free span. You could oversize the length of the 2/4 treated floor joists to extend the 2' and still be wthin the spanning tables of a 2/4 floor joist. This would provide a 2' overhang out beyond your post. Then you could frame your outside all on that cantelevered flooring extending your 2' extension that you wish for.

I can't see the flag stone even if later breaking up to cause you a problem anywhere in the normal range future of your new room.

The floor joists also allow you to install wiring and plumbing below that flooring into your main home for drains needed.

Don't forget any building, plumbing, or electrical permits requried for your project.

Just my ideas that may help

Let us know how you come out

Wg