Boundary Condition HELP
 

hello

i am simulating conduction for a layup of 3 materials using gambit and fluent. the first material is split into 4 blocks. my concern is to apply wall boundary condition to the 3 vertical lines which splits the first material apart. i was specifying solid for all faces (taking 1st material as 4 different blocks), in continuum zone in gambit, while in fluent i am unable to get wall BC for the vertical lines.i tried different possibilities but did not helped. i'll be glad if someone help me with the possible manipulation, so that i can get wall BC for the vertical lines, with the condition that the 4 blocks are solid.

thanks in advance.