I'm installing prefinished hardwood flooring parallel to a bathroom that has a marble threshold. The threshold is about 1/4' above the floor. Whats the best method to keep the boards as close to the threshold as possible and still allow for expansion?

Thanks in advance, Lloyd

If it's in a hallway with a parallel wall only three foot away, I'd fit it tight. You have space on the opposite wall for it to move it it wants to.

Its actually in my bedroom and the opposite wall is 13 feet away. Would you still fit it tight?>\

Would need to see the layout. If your not tight fitting opposite to the marble...a lot of times you can comfortably add a little extra expansion space at the opposite locations.

Or you can use an overlap transition moulding, allowing expansion at the marble, (if not wood, maybe a marble threshold). That being said, I don't like wood transitions, tight fit is a cleaner look. But you need to weigh out the situation, ie. layout, product, conditions, etc.

If it's engineered, no problem depending on species. Solid, depends on species, gluing and fastening and width of the wood planks.