I am putting down 1/2" Engineered Hardwood flooring on a cement slab using Shaw's 3-in-1 glue. The boards are tongue and grove 4.75" width. I have a fireplace hearth that I have undercut so the planks will disappear under the brick for a great finish.

Normally I was using shims at both ends of the boards length but with the fireplace hearth I won't have access to the ends.

My question is how do I ensure the boards stay nice and tight while the glue dries?

Thanks,
Andy

Most folks use blue painters tape, but make sure there aren't any mentions that it cannot be used. I know of a few manufacturers that insist it cannot be used as it can pull the finish off. Remove within 24 hours and keep direct sunlight from the area.

Ken,

I have been using the blue painter's tape for the width joints...this will work just as well for the length?

Thanks for the help.

Oh one other thing...I saw a tip that I should start laying the boards at the fireplace first instead of last. I understand the reason but how will I be able to tap the boards tight length wise with nothing to stabilize the end of the boards against? Was this a good or bad tip?

shouldn't be much more than a light tap to get it in place. If you are undercutting the hearth then it should be easy, once the glue starts to set it is not real easy to move. I usually like to go back over glue downs every hour or so and check that nothing is opening up. If it is address it then with a light tap and some blue tape.

Absolutely, start at the hearth. Otherwise you may struggle a bit trying to get the right length measurement without a few trips back to the chop saw. It gets kind of tricky for someone unfamiliar. This way makes matters easier.

Nice job on the undercut! You're way ahead of the game. Some installers don't even think about it.