Hi all,

I noticed with the 3/4" hardwood I have worked with has loose end T&G joints. What I mean by this is if you take 2 pieces of strip and insert the ends tongue to groove there is some vertical play. Some suppliers I have worked with have almost no play but one had obvious play. The side T&G joints are almost always tight although warping can make it seem tighter. Is this intentional to make the floor easier to install? I suppose it does not normally matter since the side T&G will prevent movement once installed especially since ends are staggered.

The reason I ask this is that my bordered floor obviously has many strips that end butt against the border. The ends are always T&G - either the original or a spline. In some places they squeek and I can even see the board move. This is more likely to happen here since there is no staggered end joint. I was just wondering if installers have to guard against this or perhaps my situation is unique. On my stair landing where the strips butt the landing tread I put a dab of const adhesive in the groove but I know from experience that too much glue in the groove will prevent it from closing so it's not the ideal solution. The squeeking disappears over time as expansion/contraction loosens the contact point.

My second question is regarding the router bit used to cut grooves (not in place cutting). I was told to use a standard 1/4" groove cutter with the appropriate bearing. I know they make groove cutter bits specially for use with 3/4" strip. Do these bits cut a groove that is shaped to make the tongue/spline fit tighter or is it just a square groove?

Is it better to just always cut the butted end, cut the groove and use a spline rather than the original T&G?


Thanks

Hi Alex,

Interesting observations!

I am currently installing 3/4" solid Lauzon Northern Classics, so I took my digital vernier caliper and measured a few boards and low and behold, I observed the same phenomenon with Lauzon.

The "end" tongues average .230" thick and appear to be parallel or square. The "end" grooves average .270" wide and appear to be parallel or square. This explains the looseness when butting boards. I tried a few by hand and they are all loose. I suspect that it is done intentionally by the manufacturer to make the boards easier to butt when installing.

The "side" tongues on the other hand average about .250" thick and taper slightly by about .010" (ie. about .245" thick near the outer edge and .255" thick closest to the middle). The "side" grooves average .260" and appear to be parallel or square.

I find that the Lauzon is quite loose when butting boards, but tight along the sides.

Based on the above measurements, using a 1/4" slotted router bit would probably make for a tighter end joint than what Lauzon mills into their wood at the factory. Not sure how other manufacturer's compare.

It is intentional, for ease of installation. If you notice, the groove should sit right on top of the tongue, making the loose part on the bottom side.