I've always stated that 10% (roughly 100sf) is a good amount to have left over. This is enough to remove and replace a kitchen or most of a bedroom.

If you think of the floor over 25 years you will appreciate how important it is to have a "room" worth of extra.

Most man-made flooring products have a shelf life of 18 months. That means in 18 months you will NEVER find it again...ever.

If you then calculate the failure rate of appliances (fridges, dishwashers, freezers, etc) you come up with some big expenses ever 7 YEARS! Yep. The life-expectancy of a fridge (especially one with water/ice-cube capabilities) is 7 years. A dishwasher is the same.

Imagine if the fridge fails in 3 years (damaging the subfloor = remove/replace the vinyl) and then the dishwasher fails in 7 years. You have two MAJOR repairs to the kitchen inside of 10 years. Now imagine you do NOT have enough flooring to repair BOTH events.

I would keep 2 boxes (100sf) for a 1000sf install. The other question is: will the owners get TIRED of vacuuming the ONE carpet in the home? Most people do. Regardless of age of the carpet, the homeowners start getting frustrated with the ONE carpeted room they have. And then they start thinking about putting in the same flooring.....only to find out they do not have ENOUGH floor left over. Now that's a real bugger to deal with.

First of all, I mis-typed. A box is roughly 25 sq foot and they have 10 left over. This can all be returned without any penalty as this was an in stock product at the flooring store.

I guess I was thinking that since it is a floating floor, under the flooding scenario they would just take up the floor and re-lay it.

They have carpet upstairs and a Roomba on each level for maintenance. They will most likely only be in the house for another few years.

Thanks for your input!

I would still keep roughly 100sf (4 boxes). When vinyl is pulled up (because of a leak or a flood) the edges break VERY easily. That means you lose almost 50% of the floor due to breakage.

And just because vinyl CAN be pulled and relaid, doesn't mean homeowners WANT to do it. The effort it takes to clean up a vinyl plank that has been soaking in water is quite intense. Most homeowners simply shrug, toss the old tiles and pull out the new ones (because it is SOOOO much easier).

Definitely save it. However, properly storing the leftover boxes is important. I laid VCT tile in my bathroom and had a box leftover. Good thing, because I needed to replace one of the white tile (I did a checkerboard pattern). Except I hadn't paid attention to where I was storing that box and all the tile inside was badly warped. :(

I am storing my extra boxes of engineered hardwood flooring under the beds in the guest room. Will experience the same heat/humidity as the laid flooring.