the secondary drain didn't work?

The main lines had bad PVC joints. When the water level got up to the bad connections they leaked. Same problem twice in one week.

If I install HVAC again in my own house, 1 1/2" line would be used. that damn 1/2" pvc line always clogs. I mean always.

I recently had an ac drain pipe (5/8 inch copper tubing) in my unfinished basement start leaking. Looked like the installer bent the tubing during install (obvious creation a straight run) and it took years to start leaking (house is over 10 years old). I was shocked at how much water it was pumping out. Once it started, it went from no leak to about 3 gallons per day (I live in a humid area). There is a small pump that pumps it up and out of the house do it was under a small amount of pressure.

That said, I have never seen a metal nail shield in a house including my current one where the basement is roughed in. Is that pretty common? For plumbing or electrical too?

I had a drywall nail that pierced a drain line in my house once. The house was at least 20 years old (I assume it had been there since the house was built) before the leak was as it was not under pressure and the nail pretty much sealed the plastic pipe. I just fixed it myself.

There are two types of commercial liability insurance. "Claims made" and "per occurrence".

Claims made means the insurer you have at the time the "claim is made" will respond and come to your defense. In all likely hood you do not have this coverage. This usually involves professional exposures; Doctors, lawyers, insurance agents, realtors, etc.

Per occurrence means the insurance policy that was in effect at the time of the "occurrence". The insurer you had at the time "the nail went through the pipe". This is most often what "trades" people carry.

There is a better than 90% chance you are covered covered so long as you didn't have a claims made policy and you didn't have a lapse in coverage. It's highly unlikely you did have a claims made policy being in the construction business. The only other variable is, is the insurance company that insured you at the time is still in business.

Since the occurrence was seven years ago you hopefully still have your declarations page as proof of coverage if you maintain your documents per IRS code. If not very good chance the agent still has the Dec page. Generally speaking agents must maintain client files a minimum seven years. Go to whomever your agent was and file a claim so you have coverage. Do not delay that could be grounds to deny your claim. Since the occurrence was seven years ago and you are not with that carrier any longer they will want to find a way to not cover the claim. The only viable denial is failure to promptly notify the carrier of the occurrence. So get to the agent immediately and get the claim it on record. Get a copy of the loss notice with the dates and claim number for your file and a copy of the declarations page and the carrier claims department contact information Since you are not with that carrier any longer you should not have any issues with your rates changing.

Since you have done work for this person on what seems to be a more or regular basis this could be a good client??? so you need to tread lightly if you wish to keep doing work for this client. I am gathering you are a finish carpenter? You only do the trim work? If so there is some area in which to defer liability. If you are the finish guy and the walls were already rocked when you got there how would you know if the proper plates were installed? In my area that is the plumbers job for pipes and the electricians job for wiring. It's their responsibility to protect their work.

If your carrier does come to your defense and there isn't any reason it shouldn't let them decide who is responsible to go after that's what they are there for and what you paid premium for. This really isn't that big of a deal. Don't sweat it.

Feel free to send an email if you need any advice I am 30 years in commercial insurance, 20 year Real Estate Broker and Developer. I am NOT an attorney thank god.

Good luck.

x2. Happened in my house as well after about 7 years. Hit the pipe that supplied water to the powder room. Wrecked the ceiling in the basement. I just had it fixed myself never thought of insurance.

Drop this clueless yahoo from your client list.
Life is to short for this kind of stupidity in it.

A trimmer with some common sense is going to use a detector prior to any nailing. Very easy to detect hidden electrical of any sheathing type. PVC no, but if has a some metal guard, it will pick that up and the trimmer will avoid that area.

Uh, no. Woudn't have helped here, or with romex, plaster walls, 90% of what you would encounter.

I use a magnet to find studs(screws), which is where I want to nail.

Not your fault. I would kindly explain that to the client, and also gently explain that a 'valued client' tries to work something out before reporting a 'valued contractor'.

And put a new clause in future contracts that holds you harmless for hidden or unprotected lines in the walls.