The highlighted wall cannot be joined to the highlighted roof because the wall meets the roof tangentially.

public static FailureDefinitionId WallMeetsRoofTangentially { get; }

Public Shared ReadOnly Property WallMeetsRoofTangentially As FailureDefinitionId
	Get

public:
static property FailureDefinitionId^ WallMeetsRoofTangentially {
	FailureDefinitionId^ get ();
}