What is a sprocket roof?

What is a sprocket roof?

Typically a medieval roof has a steep pitch. Look closer at the bottom end of the rafter and you’ll find it has been extended, and this extension is called a sprocket. The rafter has not only lengthened but the angle changed. The bottom rows of an old roof kick out and extend some way beyond the wall.

Why would a sprocket be used on a roof?

Used here to make the roof clear the outer wall. They are more commonly used on less steep roof pitches. When quite large they are used for decorative effect to create a sprocketed eaves, and smaller ones are used to give a close fitting joint when slates or tiles are used.

What are sprocket eaves?

Eaves Sprocket (Bellcast) A form of construction used at eaves by which short lengths of timber are fixed to the sides of rafters to give a reduced roof pitch (i.e.. flatter) than the general pitch of the main roof slope.

What are open eaves?

Open eave: An overhang with an exposed underside and visible rafters. Box eave: An overhang enclosed with a soffit and a build-up of ornamental molding so the rafters are no longer visible.

What part of the roof is the fascia?

The fascia is the attractive board along the side of the overhang and the roof that helps your roof appear finished. Your gutter sits atop the facia board. The fascia is also known as a “transition trim” between the home and the roofline. The fascia supports the shingles and helps to keep moisture out.

Is it possible to hide a sprocket on a roof?

The roof covering will always follow the line of the rafter, but form a curve made up of facets between the fascia board and the main rafter pitch; sometimes in one sweep and sometimes in two sweeps, depending upon the extension rafter. It is therefore almost impossible to hide a sprocket if it is formed within the roof structure.

Is it good practice to form a sprocket at the eaves?

It is therefore almost impossible to hide a sprocket if it is formed within the roof structure. Some specifiers firmly believe (because they have been told by their peers) that it is good practice to form a sprocket at the eaves, because it slows the rainwater down as it comes off the roof and into the gutter.

Can a sprocket be used on a cruck framed house?

Unfortunately the construction of a modern house is very different to the traditional cruck-framed house with a thatched roof covering, and therefore not always appropriate for a sprocket.

How does a sprocket work on a metal track?

For segmented metal tracks (metal link tracks) commonly used in the current generation of fighting vehicles, there are no track drive lugs as there are in band tracks. Transmission of power from the sprocket to the segmented metal track is through engagement of sprocket teeth with drive slots on the track.