We just added a support board on the inside of the vanity, where the holder's attachments went through, and there have been no problems. It is rectangular in shape, go there is additional support against the vanity trim; it remains snug and does not move around. But I suspect just the inside support board would be enough for other styles of holders, too. I experimented with the free-standing type, but they were awkward, tipped over, were the wrong height and not very attractive in the location I had to put them in that bathroom.

This post was edited by Gyr_Falcon on Thu, Feb 27, 14 at 22:17

Gyr_Falcon, Thanks for your response. An extra support board will probably do the trick. I hadn't thought of that. We will ask our carpenters to put one there. Thanks again!

I have two vanities with toilet paper holders mounted on the side. Both are open arm. One has been there for many more years than I can even guess (was there when we bought the house) and the other one I mounted several years ago.

Thanks for the info, Prickly Pear! Open arm on the side it goes!

We've had this setup for 4 months with no problems. And the vanity sides are only 1/2" thick.

I've done the same, and it's held up fine.