Just call a nice restraunt to ask the price of two dinners and go from that.

With the lowering the waste arm, you're looking at $400 minimum if you called a plumber out to do the same work. At least 1/4 to 1/2 of that as a gift card to a churrascaria style restaurant, and/or tool supply house and a nice thank you card would be appropriate.

LWO, the drain line into the wall stayed the same - just new PVC to connect the sink and disposal drains to the wall. Is that what you meant?

Maybe it's the perspective of the photo, but does anyone else see the sink drain as not vertical (it looks like the lower part is pushed to the right)?

snidely, you made me get the level, and you're right - it's not quite vertical in the plane we can see. It is vertical when viewed from the right.

Will this adversely affect the operation of the drain? Or influence the amount I should pay (when no bill was provided)?

That's at least a couple hundred in work. Hope you can return the favor somehow. I like the restaurant idea, or maybe a gift card to Home Depot, etc. At the same time, you don't want to force the issue and insult the guy. Maybe he wants to do you a favor for some reason. New baby? Newly married? Kids share the same school?

The set-up is fine. Doesn't have to be perfectly straight. Over time, just make sure the nuts stay tight in case the vibration from the disposer might loosen them.

If anything, I might make a "high loop" with the dishwasher drain hose. Gently pull any extra length of the hose into the cabinet, then loop it up as high as you can and secure it with a clamp so the loop doesn't flop back down. I wouldn't make a big deal about it, but do it myself anyhow.

From the picture, and it may be an optical confusion, that the sink is not set level. If that is true then the drain won't be perfectly vertical.

Offering money forces the issue and is awkward. Restaurant or gift card makes the gesture without putting a specific value on it and is difficult for the recipient to refuse.

Wanting to do something says a lot about you that is right and fair but questioning the quality of work done for free says something about you that is more important... you might think on that.

This post was edited by justalurker on Wed, Sep 18, 13 at 16:24

My DH is the Scoutmaster for our Boy Scout troop; the plumber is one of his assistant Scoutmasters. DH knows him better than I do. We will give him a restaurant gift card, but weren't sure of a good starting point for the amount. Since I didn't get bids (we knew he would be doing the work for us), I didn't know where to start. I greatly appreciate the feedback here!

Homebound, thanks for the tip - I'll see if I can get any more slack in the dishwasher drain.

Justalurker, I'm not at all questioning the quality of the work - snidely observed that the drain line wasn't quite level, and I asked if that was a problem. I didn't think it would be, but there's a lot about plumbing that I don't know (which is why I didn't do this job myself).

The sink level is an optical illusion - I was apparently at a cock-eyed angle when I took the photo. Here's a view from the top:

I think a gift card to a nice restaurant is a lovely gesture! It says, take your wife/girl friend and have a nice time. A Home Depot gift card is also nice but always involves work. Restaurant would be my choice!