We have a new constructed home almost 2 yrs old, we have a large shower stall on the second floor above our living room, when the shower is running we have noticed a drip sound, but we have not noticed any staining, yet. We would like to fix this before a stain appears. Our construction company only gave a 1 year warranty with our house.

You must first determine if you do indeed have a leak and if so where it is. It could be in either the water supply or the drain.
If it is in the water supply it must be between the shower valve and the shower head. It could be where the pipe to the shower head is soldered to the valve but is unlikely. It is more likely that it is where the shower head arm is screwed into the ell at the top of the pipe. Pull the escutcheon around the shower arm away from the wall and with the water running look in the hole using a flashlight. If you cannot see in the hold or you cannot be sure that it is not leaking, remove the shower head arm, coat the threads liberally with pipe joint compound and reinstall.
To remove the arm first remove the shower head using an adjustable wrench. Pliers will scratch the finish. Then remove the arm by inserting a long Phillips screwdriver into the end of the arm and use the screw driver as an extension of the pipe to give you the leverage to unscrew the arm. When reinstalling you will have to judge the resistance to determine whether you can make another complete turn. The arm must point down. If you go to far but can't make a complete turn you can't just back up a 1/4 or 1/2 turn. You must take it out recoat with pipe joint compound and start again.

If you think the leak is in the drain, make a small hole in the ceiling below where you think the trap is. Make the hole large enough to look in and large enough to put your finger in. Look and feel for water. If you don't find or feel any water leave the hole open. If you do have a leak there but can't see or feel it, the water should run out the hole before it does too much damage to the ceiling drywall.

Only advice I can offer is to take the face plate off the shower valve... run the shower and look with a flashlight in behind plate... look above (drip could be coming from shower arm at connection behind wall) and look below for any kind of staining.

Other then that.. well... I am afraid you will probably have to wait for leak to appear! *sorry*... just the way plumbing works.

BUT.. one more thought... expansion can also sound like dripping... rare, but I have heard dripping sounds only to find that like I said... expansion/contraction of pipe. I have a feeling if no stain has appeared you may have this going on and only just noticed the sounds... HOWEVER, TIME WILL TELL!!

Hey, hope this helped. Start with face plate and see from there. Good luck.

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