Fireresistance Ratings For Glue Laminated Arches

Glue laminated arches supporting only a roof and ceiling qualify as components of Mill construction under most building codes if they are no smaller than nominal 4 X 6 in. (89 X 140 mm) at any point.

GLUE LAMINATED WOOD ARCHES

GLUE LAMINATED WOOD RADIAL ARCHES

SO" 1270 mm

40" 1016 mm

30" 762 mm

20" 508 mm

15" 381 mm

Span

SO" 1270 mm

40" 1016 mm

30" 762 mm

20" 508 mm

15" 381 mm

S YS

The top chart is for glue laminated pointed arches. For low pitches, high loads, and high side walls, read toward the top in the indicated areas. For high pitches, low loads, and low side walls, read toward the bottom.

S YS

2-HINGE RADIAL ARCH

3-HINGE RADIAL ARCH

Span

3-HINGE RADIAL ARCH

The bottom chart is for glue laminated radial arches. Read the rise of the arch from the left-hand scale, and the depth of the arch from the right-hand scale.

■ The thickness of a radial arch should be at least one-fifth of its depth.

^^asonry construction rarely forms a complete building system by itself. Nonbearing masonry walls can be combined with other structural systems either in the form of infill between framing elements or as a veneer applied over wall or frame systems. Loadbear-ing masonry walls and columns can be combined with various spanning elements to form complete structural systems.

Masonry walls may be constructed in a great variety of ways. Use the following guidelines for preliminary design: Single-wythe walls are generally limited to non-bearing applications or as a veneer over other wall systems. Cavity wall construction is a preferred choice for exterior walls because of its high resistance to water penetration and its improved thermal performance. Concrete block construction is generally more economical than brick because of the reduced labor of laying the larger units and the lower material costs. Loadbearing masonry walls and columns must be steel reinforced in all but the smallest structures.

Since masonry construction takes place on-site and utilizes elements of small size, it is well suited for use in the construction of buildings of irregular form. Modular dimensions should be used, however, to minimize the need for par tial units in construction. Use a module of one-half the nominal length of a masonry unit in plan, and the height of one brick or block course in elevation.

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