In this answer, user user2264997 suggested.
You can staple it down – not as messy and fairly quick. I've used something like this on a remodel. It was 3/8" cork over plywood subfloor, then bamboo on top.
I wouldn't staple cork. Cork is brittle. Cork expands a bit, especially if it gets a little damp. If it expands and contracts enough the staples will tear and then you will have nothing keeping it together 4 years later. Probably why manufacturer says to glue. Taping the seams with something that handles moisture well is the best solution.
Could someone explain this recommendation "around the perimeter you are taping your cork to the subfloor directly along the outside edge"?
Here is how I understood it. Let's assume we work with 2'x3' cork mats. Lets start from a corner. One places duck tape sticky side down for 3' on the subfloor, along the perimeter of one wall starting from the corner, then folds the tape back onto itself to expose sticky face for cork piece #1. Since are in a corner one places another fold back tape for 2 feet along the other perpendicular wall.
Cork piece #1 in the middle of long side parallel to short sides has a folding back duck tape to expose sticky side to subfloor. Then #1 get attached to subfloor along its middle andd along its outside edges parallel to walls, 1/4 inch spaced from walls to allow expansion? We could prep #2 so it has a middle sticky side do tape exposed. It will bump against the wall on its outside short edge. so a fold-back tape along wall could be prepped? Now we lay #2 next to #1 along their long side. Attach its bottom short edge 1/4 in from wall. Now along their long edges they are touching place a tape to join them. Did I get it?
Best Answer
As mentioned in the comments of my answer most quality underlayment (minus cork) now comes with one taped side. To install the manufacturers recommend laying out the taped side in the same direction much like you will lay out the wood on your floors - for example if you have to make cuts on a row stagger them.
Let's imagine a small room. It is 12 feet by 12 feet. Your underlayment is 3 feet wide and comes in a big rolls of 50 feet long. You cut your first row at 12 feet and put it down on one side. You would at a minimum tape the three outside edges (I know this isn't easy to tape sometimes). Also the tape that DA01 used in his install - Gorilla duct tape - is high quality and not spongy like "normal" duct tape.
Now for normal underlayment I would wait until my next row was put in to tape the inside seam but for cork I will tape that to the floor too. Basically half the tape on and half the tape on the subfloor. So now all four sides are taped down.
Next row. Start with matching up the two rows and taping the pieces of cork together. Then tape your top and bottom (2 feet each). Then tape the side exposed to subfloor.
Keeping going like this. If you have cork underlayment that does not span the entire row then simple make sure that at least two sides have tape attaching it to subfloor and also taped to next pieces. And as I said you want to stagger these like your wood if you have to cut small pieces. Should never have seams within a foot.
Really it is hard to mess this up. Tape everything and match up pieces. Make sure your tape is pushed flat so your don't form ridges where your underlayment meets. If you will have a ridge (shit happens) then simply space your underlayment out from area 1/4-1/2".
Also cork is a little different because you can lay the whole room out from the get go. A big room is only an hour or two. With padded underlayment you really want to only put down the area you are at because it moves/rips/tears/messes up easier.