Building Construction Handbook, Eighth Edition

Bowed Lattice Truss Details ~

Bowstring ~

steel or softwood fishplate (x2)

laminated bow (x2)

bracket or block

strut

bows

ties

steel heel

plate

bolt and split

ring connection

laminated

tie (x2)

centre tie

packing

between bows

Belfast ~

purlin bows (2)

strings (2)

plywood gusset

packing

steel

angle

lattice bracing

sheet

decking

Typical softwood timber dimensions ~

Span (m) 6 12 18 24

Bow¾2 (mm) (^38) ¾ (^2063) ¾ (^2575) ¾ (^3275) ¾ 50
String¾2 (mm) (^125) ¾ (^20200) ¾ (^25250) ¾ (^32300) ¾ 50
Lattices (mm) (^75) ¾ (^2075) ¾ (^25100) ¾ (^25125) ¾ 25
Long Span Roofs