Types of string

close wall string

• line of noising 
• 50mm margin
• 250mm x 38mm wall string 
• rebate for plaster 
• wedges 
• 12mm deep housings for treads and risers 

Open outer string

• Dovetail balusters housed in tread 
• Cut outer string 
• planted nosing slot screwed to treads 
• Planted nosing removed .