There are several areas of squeaky floors in our house. Really, really squeaky (or creaky). One area does have access to the basement beneath it (it's our family room floor which is right above the boiler room, so we have easy access to the joists), but the other area is the bedroom/hallway on the 2nd floor (above the family room, coincidentally or not...). In any case, is it worth trying any of the various diy fixes I've seen online (and if so, what do you recommend), or just call a floor company to take a look? Both floors are original hardwood to the 1969 Colonial style house. Thank you.

I plan to cover my basement concrete floor with vinyl plank flooring. I have already ordered LifeProof Comanche Hickory planks from Home Depot (SKU 1005397004). These planks have pre-attached underlayment. HD told me that a separate underlayment is not required and should not be used. The handyman who's going to install the flooring says, he has successfully installed flooring with separate underlayment even when the planks have pre-attached underlayment. He adds, sure you can do without it, but you'll get better results with separate underlayment below. His reasons are that it'll be better for thermal expansion of the planks due to temperature changes. Also, an extra layer of underlayment will result in a softer floor feel and will offer thermal insulation so that it will not get too cold in the winter nor too hot in the summer. What do the experts here suggest - get an extra layer of underlayment or not?