Attic Flooring

[Jerry Solomon]

I have an area of my attic that I would like to floor for storage. As usual, the builder ran the romex at every conceivable angle in every direction. I see several options: (1) notch the ceiling joists at every point where the romex crosses to leave a flat surface OR, (2) install thin strips of wood on top of the joists to elevate the plywood flooring above the romex OR, (3) slip the plywood under the romex and let the romex lie on top of the plywood. Any opinions about the "best" way of handling the job?

[Dick Parr]

I would vote for number 2. #1- If there were to many notchs, you could/would weaken the roof system, :( and #3- How can you store anything on top of wiring all over the place? :confused: Plus the hassle of trying to get the plywood under all the wiring. :mad:

My 2 cents. :D

[Tyler Howell]

Jerry, I think I might run furring strips perpendicular to the joists. Your project will be more stable. If you opt. for either of your plans, be sure to protect the Romex with metal plates so you won't pierce them with nails or screws.;)

[Chris Padilla]

Yeah, DAMHIK about metal plates protecting wiring and plumbing...lord almighty.... Put the suckers IN!

[Jerry Solomon]

Thanks guys for sharing your experience and ideas. During a rebuild of an earlier house (after a flood) I noticed where a sheetrock nail had barely nicked one of the copper water pipes in the wall. It had been that way for 12 years and, believe it or not, did not start leaking until the nail was pulled out when the drywall was removed - and then it was barely a seep. Talk about lucky!! I hadn't thought about it before but I'll definitely protect the wiring. Most of the plumbing is in the slab so that won't be a concern. Thanks again.

[Michael Perata]

Jerry

The comments about nail guards should be heeded. Also heed this warning. A nail guard WILL NOT protect anything from a well positioned nail shot from a framing nail gun.

DAMHIKT

[Dennis Peacock]

Jerry.....

All the other posts have good info and advice in them. But take it from an old Ex-Electrician.........

If you ever have wiring problems...heaven forbid....but you or somebody will/may need access to the wires you will be covering up. Do what I did in my attic.....nail 2by4's about 6 inches ABOVE the ceiling rafters and from roof support to roof support providing you an unobstructed place for framing and flooring. You can still be on top of it if you need to and move stuff around, but you will NOT have to worry about wiring being in the way. If you have the attic ceiling height....raise this even higher so that you or someone else can gain access to the wiring underneath if an electrical problem ever came about and was in that area of the attic/house.

Just an idea.....

[Rob Russell]

Coupla comments ...

First, an NEC cite: 99NEC[333-12] In Accessible Attics (a) Where Run Across the Top of Floor Joists "Where run across the top of floor joists, or within 7ft (2.13m) of floor or floor joists in attics and roof spaces that are accessible, the cable shall be protected bysubstantial guard strips that are at least as high as the cable ... ". This code section [333] is actually for Armored Cable, but the section on NM cable [336] refers to it as a requirement in [336-6(d)].

So much for the code. If you have Romex running across the joists in your attic, your only real option is to install guard strips (and nail plating where needed) to lay down a floor. You can't "slip the plywood under the romex and let the romex lie on top of the plywood" because it wouldn't be protected. Notching the joists is a really bad thing to do. If you take a 1/2 inch notch out of a 2x6, you effectively make the whole joist 5" deep instead of 5 1/2" deep. Not a good idea.

If I understand what Dennis is suggesting, it means relocating the romex to a series of running boards that run around the attic but above floor level. Beware that the same "guard strip" requirement applies unless those running boards are more than 7' off the floor. There is an exception for wiring that runs along the boards (needs to be 1 1/4" recessed, etc.). Using his approach leaves access to the wiring but means you need slack in the cable to relocate it or have to install some junction boxes and splice in extra cable.

One option is to cut the wires and run them through the joists (drilling as needed). The cut/connection needs to be in an accessible junciton box, not wire-nutted, taped and buried.

Another option is to take Tyler's suggestion a step further. Run 2x4's across the ceiling joists. Those act as your guard strips and give you something easy to nail the plywood down to. TYou can always screw it down with drywall screws if you want to make it easy to remove the plywood for wiring access.

Rob

[Dennis Peacock]

Coupla comments ...
If I understand what Dennis is suggesting, it means relocating the romex to a series of running boards that run around the attic but above floor level. Beware that the same "guard strip" requirement applies unless those running boards are more than 7' off the floor. There is an exception for wiring that runs along the boards (needs to be 1 1/4" recessed, etc.). Using his approach leaves access to the wiring but means you need slack in the cable to relocate it or have to install some junction boxes and splice in extra cable.

Rob

Rob,

My suggestion does NOT require even "touching" a single wire. They stay right where they are and you build a "suspended" floor ABOVE the wiring with enough clearance to gain access to the wiring in CASE it is ever needed.

[Rob Russell]

Rob,

My suggestion does NOT require even "touching" a single wire. They stay right where they are and you build a "suspended" floor ABOVE the wiring with enough clearance to gain access to the wiring in CASE it is ever needed.



And from your earlier post ...




Do what I did in my attic.....nail 2by4's about 6 inches ABOVE the ceiling rafters and from roof support to roof support providing you an unobstructed place for framing and flooring. You can still be on top of it if you need to and move stuff around, but you will NOT have to worry about wiring being in the way. If you have the attic ceiling height....raise this even higher so that you or someone else can gain access to the wiring underneath if an electrical problem ever came about and was in that area of the attic/house.



Is the platform that you installed hanging off of your roof joists? Is there something that transfers weight down to the ceiling joists? How is the platform framed, say across a 24' attic space?

I'm asking because I'd think it's a problem if the all the weight is hung off of the roof framing. If the platform is hung off the roof and carrying a lot of weight, wouldn't it put a lot of outward stress on the walls and collar ties?

Maybe I'm just mentally picturing how this is framed all wrong - certainly wouldn't be the first time! :D

Rob

[Jerry Solomon]

First, an NEC cite: 99NEC[333-12] In Accessible Attics (a) Where Run Across the Top of Floor Joists "Where run across the top of floor joists, or within 7ft (2.13m) of floor or floor joists in attics and roof spaces that are accessible, the cable shall be protected bysubstantial guard strips that are at least as high as the cable ... ". This code section [333] is actually for Armored Cable, but the section on NM cable [336] refers to it as a requirement in [336-6(d)].

Rob - Not being an electrician, I don't understand exactly what this means. The existing (unfloored) attic has multiple romex cables running in several different directions. The cables are just lying across the insulation and ceiling joists. Is this considered "protected" or is this, technically, a violation of the Code? It would appear that the romex lying on top of plywood would be in less danger of damage from foot traffic than when I accidentally step on a cable that's crossing a joist.

[Dennis Peacock]

And from your earlier post ...

Is the platform that you installed hanging off of your roof joists? Is there something that transfers weight down to the ceiling joists? How is the platform framed, say across a 24' attic space?

I'm asking because I'd think it's a problem if the all the weight is hung off of the roof framing. If the platform is hung off the roof and carrying a lot of weight, wouldn't it put a lot of outward stress on the walls and collar ties?

Maybe I'm just mentally picturing how this is framed all wrong - certainly wouldn't be the first time! :D

Rob

Rob,

I built my house in Alabama. The roof framing was all 2 by 8 lumber, hip roof with 2 by 12's as the roof ridge AND anywhere the roof line took a turn to another side of the house. My ceiling joists were also 2 by 8's and had support framing in the attic space that would literally support a semi-truck parked on top of it. The VA inspector said it was the strongest construction of a roof that he had ever seen. ;)

I nailed the "suspended" floor ABOVE the ceiling rafters across a 12' section with the 2by's nailed to a vertical 2 by 8 roof support in the middle of the attic space. I didn't floor the whole attic....just the middle section where I wanted storage. My roof was on a 7 / 12 (seven in twelve) pitch, hip roof and I had enough room in the attic to almost play football up there.

yes....I build furniture like I build houses.....OVER ENGINEERED.!!!!!

I did the framing, roofing, plumbing, electrical, paint, trim, landscaping and such and contracted out a few of the other things that I didn't have time or resources to do. I built my house in Alabama for $27.83 per square foot and that included the carpet, cabinets and everything. In other words...it was ready to move in at that price. It was a highly restricted subdivision, so I had to meet or exceed subdivision building restrictions as well as pass every bank and VA inspection of every phase.