TYpe of string

Square nosing is using butt joint
Splayed nosing is using rebate joint
Rounded nosing is using housing joint (stronger )

• String are cut from boards of sufficient width to support the treads and risers of a flight of steps .
• Each flight of steps consists of 2 strings to support the treads and risers . 
• Wall strings is fixed against a wall or partition . 
• Outer string is the other string which is not fixed to a wall . 
• Wall string are generally made as closed string .  ( so that wall plaster can be finished to them for a neat appearance ) . 
• Outer string can be made as closed strings or as open strings  ( closed outer string does not show the profile of the treads and risers it encloses ) ( open outer string can be cut so that the profile of the steps can be seen .