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I'm looking to build an entertainment center that is 48” wide by 24” deep by 32” tall. I understand that I need to plan for wood movement for the top as it is solid wood (1 11/32” black walnut, grain is perpendicular parallel to the face). The sides are also solid wood (13/16” QS makore). Both the top and sides have the grain running one direction, simple top and sides. From looking at the specs for each wood they are practically identical from a wood movement perspective.

So the question is: do I need to worry about wood movement if I attached the top to the sides with the grain on the sides and top running the same direction?

If not, I glue the entire 24” length where the top meets the side.

If so, I attach and fix in the middle, then use zclips or whatever to attach out to the ends at 0” and 24”.

Update 2/6/2019:

Thanks all for the responses and being gentle with my feeble attempts to explain my situation. Sorry for the confusion. The Black walnut looks to be rift sawn for all intensive purposes. The Makore was labelled as quarter sawn when i got it. The makore's grain is more diagonal-ish... Hopefully this photo will clear up the confusion. Will update again with actual photos of the wood tomorrow: Entertainment Center Wood grain orientation

Update 2/7/2019:

Good question on how how to secure it. Here are some pics on what I was thinking on the top: enter image description here enter image description here As for the second photo, the pieces on the top at an angle will be the bracing members for the bottom of the entertainment center(when it is right side up). A shelf will connect to it (not pictured). Using the Festool Domino to attach the sides to the top. Then using a combination of the top bracing and z clips to keep the top secured to the unit. I think I'll avoid gluing all together.

  • This is generally the wrong way to orient the grain. I understand that there can be specific aesthetic reasons for choosing to do the opposite of what's normal (grain running along the long dimension, as on most tables, sideboards/credenzas etc.) but be aware of the consequences of doing so before you embark on the project — in doing this you create the widest panel possible for the given dimensions, maximising movement, and arranging that it will change the actual footprint of the item in case that hadn't occurred to you. [contd] – Graphus Feb 6 at 8:07
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    Now calculate just how much movement there is in flat-sawn black walnut for a 48" panel. You should see that with only a modest assumption of RH change you can expect dimensional change of over an inch in the width, and it's more than this if the humidity changes are greater. What this means is one or both sides of the piece will be sliding over the floor in and out during the year, unless the humidity and temp when the piece is going are very stable. – Graphus Feb 6 at 8:14
  • P.S. Meant to mention this earlier but forgot, are you sure about the movement numbers re. QS makore and FS walnut being equivalent? – Graphus Feb 6 at 17:09
  • Thx for the help! I can't be sure. I know the Makore is reasonably dry, as i think it has been sitting in the warehouse where i got it for at least 6 months, probably much longer. The Black Walnut is a different story. It was recently kiln dried and twisted a little over the length (10') while I was moving it in the cold. I've had both in the house for about 3 to 4 weeks before joining/planing it flat. It's been two weeks since the joining and planing and it's all straight still. Getting close to using watco on the pieces prior to final construction. Working on the supporting pieces now. – Zaxxon Feb 6 at 17:40
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    Indeed, I'll be using the festool domino to align the sides to the top. then using the cross bracing at the top plus the z-clips to keep the top attached to the unit. Was thinking of skipping a glue job... The bottom of the unit will be 3.5" thick, 2.75" of skirt, and .75" for the shelf that will extend to the back. The front sides will have 2" or 1.75" trim pieces attached. The back of the unit will be 3/8" plywood. I'll be router-ing the back sides to support the 3/8 plywood. Would be using the kreg to attach the top bracing to the top. Thx all! – Zaxxon Feb 8 at 6:34
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If the top and sides have the grain running in the same direction, then there's no need to worry about movement.

I am a little worried when you say that the grain on the top is going to run "perpendicular to the face". Do you mean the top is going to be end-grain (so the grain runs vertically), or do you mean that the grain runs from the front of the unit to the back? Either way, the top will be very weak (if you treat wood like a bundle of knitting needles weakly glued together, you won't go far wrong in analyzing how strong it is). The only safe way is for the grain to run side to side.

Edit I am no longer worried about the grain direction.

  • Thx for the help! Sorry for the confusion. I updated the question to add specifics. – Zaxxon Feb 6 at 17:42

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