AS long as you don't hit the pipe with a nail and puncture it, no concerns. Put the plate as close as you like.

You could put some scabs on the top plate and through nail into the joists, completely avoiding nails headed toward the pipe.
If the pipe is hidden upon completion and there is the remotist never-in-your-wildest dreams chance of putting a fastener into it, I would use nail plates. Pretty cheap insurance.

I was thinking the same about nail plates, in case anyone wants to run alarm wires up or something, in a case like that you'd be drilling blind. I'm not sure what the rules are about running a pipe like in the photo but it's closer to the edge than I'd put it.

Running the pipe closer than 2" to the bottom of a floor joist is already a code violation.

Pipes run within 1 1/2" of the edge of any joist, rafter, stud or other framing member must be protected with steel protection plates, period.

There are few houses on this planet that won't contain code violations.
That will be especially true for housing built prior to codes or updates in them.
In this particular case, the wall will support the weakened joists.

"In this particular case, the wall will support the weakened joists."

You determined that from smoking crack and consulting your Magic 8 Ball, did ya?

NO ONE can determine if the wall will support the weakened rafters without knowing what loads that will be imposed on those rafters.

Ridiculous answers like this one are why few should consult the interent for serious guidance when it comes to construction.

The original poster needs to talk to his local code, design and construction professionals for guidance.

Not the ravings of some lunatic with no construction experience on the web...

sheesh

Manhattan, I know what you're saying and I agree with you, but having said all that, providing the wall actually is a snug fit underneath it WILL support the joist more than it's getting now....

I think it'd be a good idea to somehow double up/sister those sections of joist before the wall goes up, if it hasn't already.

"You determined that from smoking crack and consulting your Magic 8 Ball, did ya? "

No need to resort to clairvoyance when pictures suffice. Further, ANY support on any beam at less than its original span decreases the load on the beam.
ANYONE can determine that, and would be true regardless of load.

When you "consult the interent" do you assume everyone is a "raving lunatic with no construction experience"?

You do know how to spell assume?

On the other hand, on the internet nobody knows when someone is an expert but everyone knows a jackass.

Geez, glad I checked back. First, the idea of the pipe having 2+ inches of clearance sounds like a logical thing to do...guess it was not code when the home was built 20 years ago. I will add the nail plates.

Second, to clear up any confusion about weakened joists, I (again)did not just add the pipe...it been there 20 years. My concern was whether adding a top plate along side the area where the hole was drilled an securing said top plate with two nails in the general area would weaken the joist.

Third. I am not really building a wall per say but rather two closet ends and a middle which partition off the two closet sections...one, a 6 foot opening with a set of two three foot sliding doors and the second containing a 2 foot bifold door. So looking head on one would see 3 little 'walls' coming out perpendicular to the joists which define the ends and middle section of the closet. Those 'mini-walls' would be supporting a header over the closer doors; sort of like the picture in this link (http://www.hometips.com/diy-how-to/closet-framing-build.html)EXCEPT I have 2 sections of closet where as this picture just has one AND I have no real *front* wall face...its all closet doors sans 7" of flat *front* space at each end an in the middle to attach some molding to.

I guess I am trying to say that I am not sure I am adding anything that will support the joists.....again, not sure thats even necesary. In fact since 3 closet doors will be hung from the header which is connected to the joists (allbeit supported on the ends and middle) one could argue I may be adding stress....not sure....?

To be sure, drilling or notching beams or joists in the tensile chord is a weakening stress raiser. The building codes define parameters for such alterations with good cause.
The spirit of codes is to ensure end users' safety. When people interpret them rigidly and to the letter, common sense or even engineering no longer apply.
After twenty years, your mis-bored joists bear witness to the foregoing.
My comment "...wall will support the weakened joists" assumed you are not increasing the floor (above) loading. If you are hanging the header, studs and doors from the joists, you increase loading. If you put a piano or car on the floor above you increase loading. If the header and studs transfer the load to the floor below (slab) then you are diminishing the span of the joist and thus increasing their load carrying capability.
Lest I be beset by internet code police, a disclaimer: To be a true load bearing structure, the slab or floor would require address to accomodate the increased loading, particularly with fewer contact points, i.e. one or two columns vs. the spread of a wall w/ floor plate.

Andrelaplume2,

The answer to your question is to do what you suggested. Leave a couple of inches, add nail plates and move on.

Sure, the pipe should have been run through the middle of the joists, but it wasn't -- 20 years ago. No cracked joists that I can see.

Unless they are solid granite doors, what you are constructing isn't significant to the structural integrity of the floor. Build your closets - you are fine.

Andrelaplume2, if you are concerned about the joists having been weakened, you can check for deflection by stretching a tight string along the length of the bottom edge of the joist without touching it.The string will be straight and will make it easy to see if the joist has bent because it was weakened. I doubt this is at all necessary, but you can check it if you want.

thanks all, I tend to over think these things I guess. I never really even considered the added weight of the header or the 3 hollow core doors. I was more or less thinking that nailing close to a bored hold could be a problem. Thanks for the info. I will put the nail plates up too.