Good evening all, I am planning my first hardwood floor install soon. I have ordered our new wood and it is in my house as we speak. I have removed all old flooring and prepared the 3/4 inch subfloor by removing all old fasteners, working out any high spots from removing the old fasteners, fixing squeaks and so forth. The new wood has been in my house in saint louis missouri since last thursday. I have a couple questions about the install:

A - I plan on starting the install along the longest section of the house (perpendicular to joists of course). I will spline the first row and work both ways off of that, as the flooring is going to cover 1400 square feet of my main floor (all rooms). I will be starting at the marble fireplace in my family room, so i can be sure that the wood will lay out properly around that slab of marble. my previous oak floor was "picture framed" and mitred around that marble with absolutely no expansion gap. I am worried about that but love the look. Can I do the same thing with my new install? i was told that you could simply leave a larger expansion gap on the other side of the room. That seems a bit odd to me, but it apears to be what the installers of the previous floor did. is this common practice? I cant under cut it even if i wanted to....the floor is only a hair lower than the marble.

B - I purchased a moisture meter and my subfloors are testing any where from 5 - 6.5 percent MC anywhere in my main level. The new wood is already at about 4.5 percent average on the boards that i have tested. The company that I purchased the wood from says to wait 2 weeks for acclimation, but if my MC is already within 2% of the subfloor, am I OK to proceed? My RH has been about 45-55 percent in the main floor (cheap digital meter) and the temp in the house is about 68 degrees average.

Thank you for your help in advance!

The flooring is acclimated to your conditions this time of year, but it will be a lot more humid during the summer in your area. I think that you should use a spacer between rows every so often as you lay the floor now, if you are going to use a solid oak floor vs. engineered. Just enough of a gap that will fill by the flooring expands in the summer months. What width are you going to use and are you putting down solid or engineered flooring.
The larger gap on one wall will only be good for a narrow room. The expansion will add up, so a large room needs more expansion, half on each side of the room, or small gaps spaced over the floor as it is installed in rows.

Thank you for your help! I am putting down a 3/4 handscraped seringa solid. It is 4.5 inches wide and random length. I like the idea of a spacer
Just so I understand correctly, you are talking about at the end of the boards correct? And what would be a good width....something like a dime every so often? Essentially I am thinking I shoukd picture frame the hearth, butt the wood up tight but then leave the expansion room (3/4 for that side )throughout the length of the run. Does that sound correct?

I also need to clarify, the boards will be running perpendicular to the fireplace marble.

A small gap between the flooring and the marble would be a good place to start, such a gap would be small and not noticeable. A smooth spacer will be easier to remove than something with any embossing, like a coin. A washer with a hole in it will help with removal, since it will be pinched by the sliding up of another plank. You will be able to pry it straight up with a scratch-all and pry bar instead of using pliers. Do not put the washer at the butt-joints, just every foot along the top of the tongue before you slide another plank against it. With practice you can fasten the rows together without firing them too tight. You will need to know the expansion coefficient of your wood to know exactly how far apart the rows of washers should be placed, but since you will have a more humid summer, you can just guess and it will be a better plan than without any spacers. Without figuring all the variables, I would suggest every 24 inches with a three-eighths diameter bolt washer, which would be less than an eighth inch thick. As far as leaving an ¾ inch gap at the wall, there is a limit on how well fasteners will hold if the flooring expands that much. You really would like to be perfect, leaving maybe a thirty-second of an inch between each board or less, now, since very year at this time when the moisture in the air is the same as it is now, you will see some mall gaps, every few feet, as the flooring will revert to the moisture content that you have when you are laying the floor and could shrink individually. It would be great to wait until the summer comes to do the finishing, but if it is pre-finished, it will probably have a bevelled edge, which will help with issues of swelling as the bevelled edge will prevent splintering if one edge raises higher than the plank next to it.