Yep, anyone with a hammer and the will can renovate a house themselves and make a fortune.....not.
The number of DIY disasters I have seen are incredible. Usually, it's a tradie from the wrong trade who did the work.....or a mate (and the homeowner can never remember who it was)...but fix it we must. I did some major re-wiring for a friend who died earlier this year, and we found a few things funky, but mostly it was good, just old. We did open up what was the kitchen wall, only to find a galv nail (used in the old days for drywall) that had punctured the water pipe, and somehow not leaked.
The nail has been there since around 1970 when the house was built.
View attachment 1547932View attachment 1547933