[jlsch1]

Fishinpox is right I sold building materials for over 20 years and seen the screw ups and even been on jobs selling materials thinking wow this is a screw up.

While in school I worked for my Uncle who was a licensed contractor and there is alot of things that can go wrong on a job quickly if not on top of it.
We stopped jobs before we poured concrete due to plumbing was off. How many times you seen slabs having to be cracked to rerun plumbing due to off.
I have actually seen plumbing in hallways due to drain line was layed incorrectly before the pour. Happens more than you think.
How many roofs have I seen screwed up or shingles slide off during 1st wind storm due to pop the shingle using nail guns.
I guess OC, Atlas, Tamko, and GAF all made a bad batch of shingles in that neighborhood or was it the common factor a bad installer.

I have to deal with homeowners, but I rather deal with contractors due to less errors that need to be corrected.
Seen $3,000 front doors installed by so called contractors and I just wanted to laugh when they cut the door instead of adjusting the threshold cap.
Windows being installed incorrectly seen that as recently as last week on an apartment job.
None of the windows were installed square, so they wouldn't close right. When they reinstalled them correctly they closed correctly. It happens alot.
Seen $20,000 engineered lumber package get very screwed up by a so called unlicensed contractor.
Slabs or foundations of the homes crack where I believe a licensed contractor liable for x amount of years if this happens.
That alone I would make sure my guys are licensed.
99% of customer complaints with materials I sold were installed incorrectly.
98% of those problems come from jobs that were done by unlicensed contractors or subs.
98% of the time those costly errors cost the customer alot of money to repair.
1% of problems are actually the product being defective.
1% of problems a licensed contractor screws up by error I will work with them due to I will see his business again.
Homeowner once he is done with that house its over with I will never see them again and cannot justify eating error that is not a material defect.

Worst problem over the years I seen is where a subcontractor who does not carry insurance and is not licensed has someone on his crew get injured and seen three cases where people died. It falls back on the homeowner due to I believe if your acting as the contractor your also holding yourself liable for incidents such as people getting injured on your job.

Fishinpox could probably tell you more about that due to he is licensed and probably knows more about the rules regarding this.