private FabricSheet CreateCustomFabricSheet(Document document, Element wall)
{
   if (FabricSheet.IsValidHost(wall) == false)
      return null;

   // Create a new type for custom FabricSheet
   ElementId fabricSheetTypeId = FabricSheetType.CreateDefaultFabricSheetType(document);
   FabricSheetType fst = document.GetElement(fabricSheetTypeId) as FabricSheetType;

   // Create some fabric wire types
   ElementId idWireType1 = FabricWireType.CreateDefaultFabricWireType(document);
   FabricWireType wireType1 = document.GetElement(idWireType1) as FabricWireType;
   wireType1.WireDiameter = 3.5 / 12.0;

   ElementId idWireType2 = FabricWireType.CreateDefaultFabricWireType(document);
   FabricWireType wireType2 = document.GetElement(idWireType1) as FabricWireType;
   wireType2.WireDiameter = 2.0 / 12.0;

   // Create the wires for the custom pattern
   IList<FabricWireItem> majorWires = new List<FabricWireItem>();
   IList<FabricWireItem> minorWires = new List<FabricWireItem>();
   FabricWireItem item = FabricWireItem.Create(2.0 / 12.0, 1, idWireType1, .0);
   majorWires.Add(item);
   majorWires.Add(item);
   item = FabricWireItem.Create(1.5 / 12.0, 10.0 / 12.0, idWireType2, .0);
   majorWires.Add(item);

   item = FabricWireItem.Create(3.0 / 12.0, 1, idWireType2, .0);
   minorWires.Add(item);
   item = FabricWireItem.Create(3.0 / 12.0, 10.0 / 12.0, idWireType2, .0);
   minorWires.Add(item);

   fst.SetLayoutAsCustomPattern(6.0 / 12.0, 4.0 / 12.0, minorWires, majorWires);

   FabricSheet sheet = FabricSheet.Create(document, wall, fabricSheetTypeId);
   // Regeneration is required before setting any property to object that was created in the same transaction.
   document.Regenerate();

   AnalyticalElement wallElem = null;
   AnalyticalToPhysicalAssociationManager assocManager = AnalyticalToPhysicalAssociationManager.GetAnalyticalToPhysicalAssociationManager(document);
   if (assocManager != null)
   {
      ElementId associatedElementId = assocManager.GetAssociatedElementId(wall.Id);
      if (associatedElementId != ElementId.InvalidElementId)
      {
         Element associatedElem = document.GetElement(associatedElementId);
         if (associatedElem != null && associatedElem is AnalyticalElement)
         {
            wallElem = associatedElem as AnalyticalElement;
         }
      }
   }

   sheet.PlaceInHost(wall, wallElem.GetTransform());

   // Give the user some information
   TaskDialog.Show("Revit", string.Format("Flat Fabric Sheet ID='{0}' created successfully.", sheet.Id.ToString()));

   return sheet;
}

Private Function CreateCustomFabricSheet(document As Document, wall As Element) As FabricSheet
      If FabricSheet.IsValidHost(wall) = False Then
          Return Nothing
      End If

      ' Create a new type for custom FabricSheet
      Dim fabricSheetTypeId As ElementId = FabricSheetType.CreateDefaultFabricSheetType(document)
      Dim fst As FabricSheetType = TryCast(document.GetElement(fabricSheetTypeId), FabricSheetType)

      ' Create some fabric wire types
      Dim idWireType1 As ElementId = FabricWireType.CreateDefaultFabricWireType(document)
      Dim wireType1 As FabricWireType = TryCast(document.GetElement(idWireType1), FabricWireType)
      wireType1.WireDiameter = 3.5 / 12.0

      Dim idWireType2 As ElementId = FabricWireType.CreateDefaultFabricWireType(document)
      Dim wireType2 As FabricWireType = TryCast(document.GetElement(idWireType1), FabricWireType)
      wireType2.WireDiameter = 2.0 / 12.0

      ' Create the wires for the custom pattern
      Dim majorWires As IList(Of FabricWireItem) = New List(Of FabricWireItem)()
      Dim minorWires As IList(Of FabricWireItem) = New List(Of FabricWireItem)()
      Dim item As FabricWireItem = FabricWireItem.Create(2.0 / 12.0, 1, idWireType1, .0)
      majorWires.Add(item)
      majorWires.Add(item)
      item = FabricWireItem.Create(1.5 / 12.0, 10.0 / 12.0, idWireType2, .0)
      majorWires.Add(item)

      item = FabricWireItem.Create(3.0 / 12.0, 1, idWireType2, .0)
      minorWires.Add(item)
      item = FabricWireItem.Create(3.0 / 12.0, 10.0 / 12.0, idWireType2, .0)
      minorWires.Add(item)

      fst.SetLayoutAsCustomPattern(6.0 / 12.0, 4.0 / 12.0, minorWires, majorWires)

      Dim sheet As FabricSheet = FabricSheet.Create(document, wall, fabricSheetTypeId)
      ' Regeneration is required before setting any property to object that was created in the same transaction.
      document.Regenerate()

   Dim ams As Autodesk.Revit.DB.Structure.AnalyticalElement = Nothing
   Dim relManager As Autodesk.Revit.DB.Structure.AnalyticalToPhysicalAssociationManager = Autodesk.Revit.DB.Structure.AnalyticalToPhysicalAssociationManager.GetAnalyticalToPhysicalAssociationManager(document)

   If (relManager Is Nothing) Then
      Return Nothing
   End If

   Dim counterpartId As ElementId = relManager.GetAssociatedElementId(wall.Id)
   If (counterpartId Is Nothing) Then
      Return Nothing
   End If

   ams = document.GetElement(counterpartId)

   sheet.PlaceInHost(wall, ams.GetTransform())

   ' Give the user some information
   TaskDialog.Show("Revit", String.Format("Flat Fabric Sheet ID='{0}' created successfully.", sheet.Id.ToString()))

      Return sheet
  End Function