Loose Tongue in Groove Boards


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13 Feb 2023
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Alderney, Channel Islands

I was wondering if someone can give me some tips on creating a garden gate with the joinery of a loose tongue in ajoining boards. I plan to complete my task over the weekend. The information I'm after is

  • What depth of the groove should have vs the loose tongue
  • should I use the same wood the boards are made out of?
  • Should the tongue be loose or a tight fit? (yes I know I've called it a loose tongue before ;))

Any other tips, comments or resources would be much appreciated

Thank you
9mm deep grooves so 18mm wide tongue, minimum 2mm gap between boards which gives the tongue at least 2mm clearance.

Tongue not too tight and give it a coat of whatever you are going to finish the gate with before you assemble it.
Just to mull over tongue and groove a bit. I've started to use rebated shiplap style that's not to tight on outdoor stuff i just think it's less of a pain as it doesn't tend to jam after painting. Loose tongue is even trickier to protect than t and g.