Take a look at ti videos tutorial about how to model a Roof in 3dsmax with AvizStudio Tools - ATiles...
ATiles is scripted 3ds Max plug-in for quick creation of tiles, paving floors, brick walls, roof tiles, fences and other objects of repeatable elements for architectural visualizations.
New in version 1.4:Set internal scale of the sub elements for X, Y and Z.
Auto optimization of sub elements when creating new object.
New video - How to cover with ATiles complex roof .
Installation:Download and unzip the desired version.
From 3ds Max menu select: MaxScript> Run Script ... > AvizStudioTools_ATiles.mse
If you want to load script automatically copy the contents of the archive in the 3ds Max root folder\scripts\startup\.
Version Requirement: 3ds Max 7 or later
Here you can download AvizStudio Tools - ATiles script