In the garret the roof appears as a purlin roof supported on principal rafters. These rafters, on the front, the northside, are, almost all of them, the old rafters dropped to a lower pitch-dovetail cut for the collar beams shows this, for the bottom of this cut, which should be level, is inclined downward
...The collars have all disappeared.

    In the floor of the garret, or rather where the floor should be, over the back of the present chimney, there is still a floor joist and there are, in the girt, the mortises for others.

NMI

    The original roof is framed on seven principal rafter pairs joined by collar beams that are mortised and tenoned to the gable pairs and half-lapped and dovetailed to those in between...They support horizontal, not vertical, roof boards, which date from construction of the parlor addition.

CC

Attic
Photo by Haroon Samnani