I am installing 3/4 hardwood oak nailed down to plywood sub-flooring. If hardwood flooring is installed first, wouldn't buckling of the floor be a issue since hardwood expands and contracts?
There are several factors to consider. Buckling would be the least concern if the hardwood floors are installed properly. I would lay the floors first and then install the cabinets. I have been involved in the construction of hundreds of new homes and we have always laid the hardwood floors first.
- Appliances - The height of the cabinets needs to be 36 inches from the floor. The appliances will need to be the same height. Do you really want to be forced with having a lip in front of all the appliances? You would basically be sealing them in. Imagine having to pull out a refrigerator when it's boxed in with hardwood.
- Labor - In relation to the appliances, you would need to place some plywood, etc. underneath the cabinets and appliances to raise them up. What would be the point? Both options probably cost about the same.
- Leaks - Imagine an unnoticed sink leak. If water runs under that flooring you will definitely have some buckling issues to deal with. A sink leak on a hardwood floor would be bad anyway, but you would be creating an easier way for the water to enter underneath the hardwood.
- Insects - Roaches love cracks and crevices. You would be creating a welcoming environment for all manner of insects given the warmth and moisture from your appliances.
- Remodeling - Hardwood flooring will outlast the cabinets. You might also want to change cabinets someday for a different style. You will be faced with having to go back with the exact size cabinets.
Definitely flooring first! Your ends do not have to be perfect that go under the cabinets, so if you have boards with bad ends or flaws, they can be placed so that flaw is hidden by the cabinet. I'm 6' something and every 1/4" of higher cabinets counts, so I'd do it just for the fact the cabinets are not 3/4" shorter/sunk in. Some appliances allow you to remove the feet to shrink them down to your lower cabinets but it would be an absolute nightmare and would easily damage the floor when moving them without feet. It's more intended for a retrofit job - this is NOT the case!
Floor under the cabinets! If you're worried about damaging the floor, buy a roll of construction paper and tape it down to the new hardwood. Then put an old drop cloth over it if you have one.
In the case of an existing kitchen installation where the existing flooring (vinyl, for example) was replaced with hardwood, the new flooring goes up to and around the cabinetry. It's done, but not ideal because of what happens around or under the appliances. It also lowers the effective height of the countertop by the flooring thickness.
Since this is a full reno, far better to lay the floor first and then install the cabinets.
I had my kitchen replaced, kept the original tile floor. What I found when the old cabinets were removed was that the tiles didn't cover the entire floor - they only went far enough under the cabinets (a few inches) to provide for a finished look at all the edges, and I think also to provide a level surface for the cabinets to rest on.
The flooring covers every inch of floor area visible when all appliances are removed, is the supporting surface the cabinets rest on, but doesn't have to run where it has no job to do (as either support or finish).