I've added an album to the DIY Heaven link, courtesy of the devious mind of Guest Member Denny McGinnis.  It's called "Inspection Nightmares".  Now that you are done laughing at other's fool hardy fixin' uppers, here's you chance to share some of your own Inspection Nightmares.  Go ahead!  Get it off you chest !  Ha! Ha!

I have seen some of these DIY jobs through my work (home energy auditing). I've seen several plumbing screw-ups, such as: the hot and cold water lines being reversed. The new home owner telling me that they don't have much hot water--only a minute or so. Because the lines were reversed at the hot water tank, the hot water would be diluted with the cold coming into the top of the tank rather than the bottom. I just told them that the previous owner must have done the work themselves because a plumber won't have done that kind of work. Another was the lines were reversed on the back of the washing machine. That can be tricky---hot is always on the left and cold on the right but when you are looking at the washer face on then the hot goes on your right --which would be the left from looking at the back of the washer. The woman was very thankful that I turned the lines around for her. Also, I've seen all kinds of lighting,electrical, carpentry and bricklaying messes through-out the years I've been doing these audits. I've seen copper lines on plumbing for the hot water tanks(which is a no-no) rather than black iron pipes.

I've seen attics converted into bedrooms, with ceiling joists and knee wall studs two feet on center (which isn't good) rather than 16" on center. Also, insulaton installed every which way in the attic (it wasn't doing much good) in some DIY installations. Some times trying to save money by DIY jobs costs more in the long run. 

Re: " I've seen copper lines on plumbing for the hot water tanks(which is a no-no) rather than black iron pipes". Jerry, are you talking about the water lines, or the gas lines ???  Please clarify.

Denny,  I'm talking about GAS lines. Many homes out there are in violation of city codes and simple common sense issues. We auditors are required to call the power companies if we smell any gas in the home. This is for the safety of the home owners. There have been times when I had to do that. The power company comes out very quickly and find the problem. As far as electrical, you know that extension codes are a definite hazzard in any situations. Many older homes only have one outlet in each room and today we have so many electrical appliances. That's where the extension codes come into play.  Dangerous all the way.

   I was pretty sure you meant the gas lines - - I just wanted you to clarify it for our readers.

  One old house that I was rewiring had "lamp cord" for the power source between two outlets, and the breaker it was wired to was a 20 amp.  It was buried under the sheetrock. I assume that it was done by a homeowner. Needless to say that if anything bigger than a lamp was plugged into it, it would have burned.