Virgil,
I take the point about bad painting, bad carpentry, etc. On the plumbing, I was thinking along the lines of somebody trying to install a pressurized hot-water system and not allowing for expansion, not fitting temp/pressure relief valves and so on. That has resulted in some quite nasty accidents when a cylinder finally goes kerblam. By the way, like electrical work, we have no restrictions on who can do plumbing, but the govt. did introduce a law to make it illegal to work on gas systems unless suitably certified.
Bill,
Interesting point that even if the person a response is directed to understands, somebody else reading the messages afterward might not. That's certainly how a post on a forum such as this differs from advice given face to face.
I must confess that I've sometimes had kids follow me around intently, watching everything I do, but I've not considered the aspect you mentioned. Put it down to me being obsessed by electricity since the age of about 6, I suppose.
Time for me to rant a little myself now. A few years ago I saw a "How To..." video tape in my local library which supposedly showed a complete beginner how to move a light fitting, install an extra receptacle, and so on. Out of curiosity I decided to watch the tape.
I very soon found myself questioning much of the advice given and seriously doubting whether the average homeowner would be able to follow the instructions properly.
I forget the exact details now, but one part was something along the lines of changing an existing room light to 2-way (U.S. 3-way) switching and adding a wall light. The "guidance" they gave to the wiring of the lights and switches was hard to follow, to say the least. I remember that the first time through I was totally lost as to what they were doing. I watched the section several times and still couldn't figure it out. In the end, I had to get a pencil and paper and go through the tape hitting pause every few seconds to sketch out what was being done.
Eventually I realized the way they were doing the wiring. It was all done on the assumption that the existing wiring had been done a certain way, with no allowances for the fact that any one of several methods could have been used. Anyone just blindly following their instructions, particularly on an older property, would most likely have gotten in a terrible mess.
Now if I had to watch the tape a dozen times and sketch out each step separately to figure it out, what chance would the average DIY homeowner stand?
The sort of advice given by that tape could've gotten someone into real trouble. I found the whole thing so misleading that I made a point of explaining my concerns to the librarian.
