The phrase "wooden planks" refers to flat pieces of wood that are long, thin, and often used for building structures or making furniture. Full definition
The pit would then be covered with wooden planks and the ice stored until the summer months when it was used to cool their drinks. (joyofbaking.com)
From a formerly covered parking garage enclosed by wooden planks and a mesh fence, has emerged a wonderful light filled space. (projectspacefestival-berlin.com)
I love it all but especially the horizontal wooden planks in some of the rooms. (theinspiredroom.net)