Not sure what the original installer used on the sink that didn't leak, but the second guy definitely used silicone. Guess it will be a pain to remove should that ever be necessary. I know that I have plumber's putty in my rudimentary plumbing repair stuff, but I wasn't doing the install. (I have, however, replaced a drain assembly in the past, and am fairly sure I didn't use silicone). I just checked the Delta instruction sheet and see that they say to put silicone under the flange - no mention of plumber's putty at all!
No - the company was not a "rooter" one. It isn't even part of a chain - just a local plumbing, heating and electrical firm (which also sells toilets, sinks and taps, etc., but not the models I wanted) that has generally had a good reputation in my city. In retrospect, perhaps I should have looked for a plumber only. But construction where I live is absolutely booming and it's tough to get tradespeople when you need them. I should have tried somewhat harder.
I know that on the toilets forum it has been said that the "big box" stores sometimes get substandard quality items from manufacturers who do supply first quality goods to others. Is the suggestion that faucets are among the items? Through whom should one buy fixtures, then? (I'm not sure whether RONA, the place where my faucets were purchased, is considered to be a Canadian big box store, but likely). I know that when I looked for Toto toilets in my city I found that the only two suppliers here not do installs. Another outfit sells Toto and installs them but gets those fixtures from one of the two suppliers with whom I dealt - and charges exceptionally high fixed prices to do the installs.
Just glad I'm about done with renos for a bit...
Had a kitchen reno done about 3 years ago and did have a "real plumber" do the work. The cabinet installer commented that the guy did things in an old-fashioned manner (maybe a good thing). But the guy was obviously not hurting for money - didn't even send me a bill for about 18 months - even though I phoned several times as I wanted to make payment and only had the estimate in hand.