I'm in the middle of a glue-down install. I've cut 27.5" planks using a fence I built, and the widths vary:
2.5", 3.5", 4.5" and 5.5". I'm gluing down two rows at a time, from the center most top off the room, with the first two boards
screwed into the concrete.
My question is how do keep the boards snug? If I get one row right, other rows or boards slip slightly.
Any suggestions?

I'm at a loss on how your installing a herringbone pattern using random widths ?

Whatever your trying to do....You can run blue painters tape over your previous rows, to keep them tight, while your continuing.

I think I read an earlier post of yours which mentioned the tape on Herringbone install. Bought it earlier and giving it a try tomorrow.
Regarding widths, each long row across the width of the floor consists of boards the same width.
Example:
one row
\/\/\/\ = 5.5
next row
\/\/\/\= another random width

If gaps happen, will the finish fill them if they're small, or should I use a filler of some sort?

Ah ha...now I know what your doing. Couldn't picture a random width herringbone. Should look good! Hope to see pictures!

I'm not a sand and finish guy but... I believe the guys trowel fill herringbones, or most "modular" patterns. I've also heard that S&F on a herringbone really seperates pros.

Trowel filling may be the best option. Is that and colored wood filler the only other option? Our floor is a mixed variety of wood species and colors, old/distressed & reclaimed from barns. Just doing a Neutral/Natural Stain/Seal on it.

the ramdom width still needs to be installed from center course, top to bottom, otherwise you will run out of square..

as for filler, it is what it is....just make a sand dust fill and trowel in using glitza wood flour....

Hey James, this being our first floor, can you detail what you mean by:
"installed from center course, top to bottom, otherwise you will run out of square"

I've already started the gluedown from the top most area of the room,
working mainly the center column: /\
and working the column to the right a little slower.
There's 290sqft total to the the room.
I'm nearing the halfway point of the center column and have managed to keep it square so far,
although I've been having to work it slowly, nailing and weighting down squares and borders to keep it in line.
Mostly 5 rows at a time per column max, and leaving it for at least 12hrs before starting back up.
Painfully slow, but any more, and they start to shift.

I'm not James..but I think what he's saying is the same way I've always installed Herringbone...chalk lines, and install up & down, "vertical", and from the center of the area, out in both directions. I think that's what he's saying. But I don't see why you can't chalk lines and install "horrizontal", keeping everything square, just the same. Maybe that's not even what he's saying

Howard,

that's is what I am saying......and you cant go horizontal...if you want to find out the hard way...give it a try;)

you will always run off

James, Nah..I'll pass...thanks just the same!

Just to clarify, here's the layout of my rows (sorry for the backwardsness of the alphabetizing):

G F E D C B A 0
/ \ / \ / \ / \

I've started gluing with Row D & C, at the top (there's 50 boards to each row)
at about 10 rows down, I started row B & A. The lag between columns is so that
I can use the center-most column (D & C) as an anchor.
I'm at Row 35 w/ D&C currently, and Row 25 with B&A.
So far everything's still Squared fine and is still lining up correctly on the centermost chalklines, although I have some gaps on the ends of the boards in Row B.
The boards in Row B are also getting a little tighter..
Regarding the "running out of square" comment, will I be running into a potential problem anywhere?
If so, is there any way to fix it at this point?