Floor help please

[farrier!]

I have an overhang off of our barn/garage I will be making into the chicken house. It will be 16 by 16 feet. We are prone to a bit of flooding with often water running through the backyard. Because of this I want to put in a raise floor.
Unluckily I know nothing about floors.
I am assuming I can attach to the existing garage wall but do not know about spacing or how to attach/nail the support boards for the floor.

Any help? Can I use 2x4's or do I need 2x6's? Can they go 16' without support under them? If not what do I need to do? It is pretty much mud .....

I have built sheds and barns but with horses a hard base of dirt/rock is all you need......

 

[GardeNerd]

Could you pour a cement slab under the area? I have cement under my coop and run with 2-3" sand in the run. It drains well.

I wish I could help more, but my expertise is in gardening, not construction. Maybe this will bump the thread up and you will get some better advice. Good luck. Post a pic and maybe folks can better visualize what you are looking for.

 

[DarkWolf]

There are several options for attaching a raised floor to an existing structure.. If you could take a few pictures and put them up, that would help greatly.

As for the 16' span, you would be best having support piers under every so many floor joists @ the 8' mark. You may need to do this anyway, if you're unable to find joists long enough and then just scab two 10'ers together in the center with cut scrap and support with piers, or even a block wall.

You will want to go with at LEAST 2x6 joists. If you ever plan on putting anything heavy in it, go with 2x8 and like I said, you will most likely need to split the span into two 8' sections and support the center.

Here are some ways to support long span joists with a girder in the center. Either sandwiched 2x6's, or a 6x6 for the girder.

Here's a good page for you to look over.

http://www.carpentry-pro-framer.com/floor-framing.html

For the center, scroll down to Floor Framing on Wooden Girder to see what I mean.

Far as against the walls, it depends on what you have to work with. If the bottom plate is off the ground on a cement or block foundation, you could just frame the floor joists up against it. Else you'll need to bold a ledger to the existing wall studs and then frame the joists off of it.

 

[LilbitChicken]

My hubby is the one who build everything around here.... but
with the flooding/muddy area...you will need to elevate the coop!

Even cinderblocks, then the 2x4 base....

 

[patandchickens]

I agree a raised floor is by far your best option.

For attaching the end of the joists to the garage wall, what DarkWolf said - you need to attach a ledger board to the existing wall. In a normal house you would bolt into the existing (big lumber) sill, not the 2x4 studs, though - you would want to contemplate how overbuilt the existing garage wall is, if you expect it (especially, its studs, if you want to *really* raise the floor as opposed to just a foot or so) to carry the extra weight of part of a 16x16 coop.

For the rest of the bldg you might also consider pole type construction (as opposed to just sitting on blocks), that would be the sturdiest construction for that size of a structure and is easy and inexpensive to build. I'd suggest not trying to go for a clearspan building but put a post or two in the middle, it simplifies the engineering and makes construction cheaper overall.

Good luck, have fun,

Pat

 

[DarkWolf]

Quote:
This brings up another idea. If you don't want to, or don't feel you're capable of doing a raised floor which ties into the walls, you could basically just build a deck inside a building.

You'd have to dig down just like a normal deck and install footings, concrete in some 4x4 posts and then attach to them. Then sheet with plywood. Basically a deck inside a building.

But... Doing a ledger and floor joists would be the better option.. It's really not that hard.

And yes.. Poles set in concrete as a footing for the center girder would be the best and strongest option. Also easier for that matter, since you don't need to level block. Just cut the posts off at the size needed to support the girder and then work off of that.

 

[farrier!]

Thanks for the information everyone, that has helped!
I will try to get some pictures on here soon.