Why is a material not covering entire actor

Im hoping someone can tell me why the material is not covering all the edges of the actors in my model. You can see in the pic how some sides of the walls are not painted.
What am I doing wrong?
Version 4.10 windows 10)

Static mesh or BSP?

If its BSP you need to select and apply your material to those faces.

If its a static mesh, then you have used too many material IDs on your mesh in the 2d authoring program. Usually for 3dsmax people use the “Multi Sub Object” material type and make sure they only assign out the same number of material IDs as the multi sub object has. That seems to be the safest way.

Thanks RYan!
I could have sworn I had tried that (BSP) and it hadnt worked but now it does!
oh well