Hi All,

I will be installing some 3/4" solid prefinished Brazilian Oak that is 4.75" wide on a second floor 3/4" OSB subfloor. I have three questions:

1) I have read on some posts that many pros recommend glue and staple for 4" or wider planks. I was wondering what the opinions are on just stapling and no glue, given my installation as:
- I live in inland San Diego, where we have very mild weather. Dry summers, and mild rain in the rest. It's pretty easy to keep the indoor conditions consistent
- The installation is on the second floor over joists as opposed to something over ground
- The flooring is 4.75" wide

2) I have to do stairs as well and I remember reading somewhere that it is a good idea to start from the bottom of the stairs and move up to help with the layout. I don't know why that is and cannot find the same info again. Any opinions on where to start laying the flooring?

3) I would like to reduce the noise transmission from upstairs to downstairs. Unfortunately I cannot afford a real noise reduction solution such as putting down cork with glue, then another layer of 3/4" subfloor with glue, then hardwood. I also would like to avoid paying 50 cents per square foot for some fancy Quietwalk underlayment, which may not help more than just some thickness of cheaper underlayment. What do you think about 2 or 3 layers of 15lb roofing felt?

Thanks,
James

If you havent put the underlayment down, I would suggest the foam sound barrier sold at most flooring distributos beneath it. I do not recommend trying to install the flooring directly over the pad, it is sticky and is difficult to install over.

I wouldn't recommend more than one layer of 30 pound felt, especially if you are concerned with fastener strength with a 4.75" plank

If the wood is acclamated correctly, the mill's end match is tight and you use a correct amount of fasterners you will not have a problem without glueing.

There are plenty of reasons to start from the bottom of the stairs.
For one, if you are going directly of the stair jacks, you can nail the bottom of the riser to the back of each tread.

Hi jabwoodworks,

Thanks for the reply. When you said that you wouldn't recommend installing the flooring directly over the pad, do you mean that I should put a layer of roofing felt (or rosin paper) on top of the foam and then nail in the flooring.

Thanks,
James

I meant that it would be easiest to put the pad under the plywood. The pad that I am referring to is also the moisture barrier.

J

Oh, I see. Unfortunately the 3/4" OSB is already in place, screwed in tightly

Why would a couple of layers of 30lb roofing felt be bad for fastener strength? Is it fastener length issue or something else?

Thanks,
James

I did a shim once between two varying heights of subfloor with tar paper. It was fine at first but later the area became slightly squishy and then lead to loosening fasteners. I attributed this to having two hard materials and a soft one in the middle, with regular travel over the top.

Fortunately the lady never mentioned it and then her dishwasher over flowed. When I replaced the wood I shimmed it correctly with wood and a sander.