I would go with the lino. The stone curb under the W/D is good if the leak happens close to the machine, but I worried about a leak/flood where the hose hook ups are or even out the door of the Washer. We put a drain directly under the Washer. The floor gradually slopes (you can notice it) towards the drain. Then it's sealed around the baseboards. With the vinyl flooring it will help (hopefully) in case of a leak.

I have a 2nd floor laundry "closet" -- just the washer & dryer, both full size, in a closet with folding doors. When I remodeled, I had a floor drain installed in the floor, and had ceramic tile laid onto the floor, along with tile wainscoting. I wanted to ensure there would be no leaks from this closet. Everything works well, no rattling/shaking going on, and it's been in place for nearly 5 years. I'm delighted with the results. The tile closet opens onto hardwood floors. Both the hardwood floors and the tiled floors are laid on top of sub-flooring that's made of particle board, if I remember correctly.

Ask yourself how confident you be of any drain if there were a burst hose pouring out 500 gallons an hour. Do you think a burst hose will cooperate and pour all that water into your nice new drain. Imagine that happening when you are at work, out for the evening or away on vacation. Will the drain promise to stay open and clear if it is handling 500 gallons an hour for 8 hours, two days, a week? I'm sorry, but anyone who says it is enough to have a drain has not lived through this, thinking through this and/or done the research. Second to ruptured refrigerator ice maker hoses, ruptured washing machine hoses are the most common home owners insurance claim. When this occurs the water damage is unbelievable. 5 figures in damages easy, then all the hassle and worry about mold, mildew and drying out your house. The key to any upstairs laundry installation is in redundancy - multiple preventative measures - with a drain being perhaps the last line and not at all the most effective. First, you want a manual shut off handy so you can turn off the water supply to the valves/hoses when you are away for long periods. Second, you want the best hoses you can get. I have a Miele washer and despite its $2000 price, I threw the hoses that came with it right in the trash and use these - Floodcheck. They are unbelievably well constructed and not expensive. http://www.safehomeproducts.com/shp2/sm/flood-chek.aspx Third, you need an electronic shut off valve with leak sensor. I use the Burst Buster. I had tried the Watts Intelliflow, but it failed after one year. It was junk and the Burstbuster is much better. http://www.aymcdonald.com/burstbuster.cfm Forth you could install a pan. The pan may or may not have a drain connected to it. However, despite the back up problem your plumber brought up, what about the drain trap drying out? All drains need to have a p trap. The trap serves an important purpose in keeping sewer gas out of your home. How does it do this? There is always a small amount of water in the trap that acts as a barrier. In a laundry pan drain you will never run water through that drain so it will dry out and as a result sewer gas will enter your home. Ask your plumber how he can give you a drain that wont back up AND won't dry out AND be in code? I'm sorry to sound preachy, but I see the same bad advice on these forums over and over. Drains present many problems and expense, but their purpose is to deal with a failure (leak). You need to concentrate most on multiple ways of *preventing* that failure in the first place. Right? Actually "leak" is the wrong word. "Torrent" is more appropriate when it comes to washing machine hoses. Do you have a washer in your basement?Just for fun, take off the hose and turn it on while pointing it into the sink. Picture that happening in your upstairs

You could probably delay start the wash cycle but I think the spinstart will have to begin on or after the alarm clock going off...the models have come a long way as far as vibration issues, but the reinforced floor, washer near a corner and drain in the floor are all excellent ideas. Perhaps you'll have a laundry room with enough space for sorting bins, an ironing board and a drying rack too?