Scribd
Upload
567 views1 page

Aama - Tir

The document discusses guidelines for allowable deflection of building cladding framing members based on span length. For spans up to 4110 mm, deflection shall be limited to L/175. For spans greater than 4110 mm up to 12 m, deflection shall be limited to the more conservative of L/240 + 6.35 mm. Spans over 12 m may require additional analysis.

Uploaded by

Abdul khaliqu
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
567 views1 page

Aama - Tir

The document discusses guidelines for allowable deflection of building cladding framing members based on span length. For spans up to 4110 mm, deflection shall be limited to L/175. For spans greater than 4110 mm up to 12 m, deflection shall be limited to the more conservative of L/240 + 6.35 mm. Spans over 12 m may require additional analysis.

Uploaded by

Abdul khaliqu
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
You are on page 1/ 1

Following is an “Allowable Deflection Comparison” chart which depicts the span/deflection relationship based on L/175 and L/240

+ 6.35 mm (1/4 in). “L” denotes clear span, i.e., length of member between reaction points. This chart was prepared to create a more
conservative upper limit on deflection for spans greater than 4110 mm (13 ft 6 in).

Span (Feet)
0 5 10 15 20 25 30 35 40
70

2.5
60

50 2.0

40
1.5

30

1.0

20

0.5
10

0 0
0 1 2 3 4 5 6 7 8 9 10 11 12

Span (Meters)

ALLOWABLE DEFLECTION COMPARISON


The L/175 and the L/240 + 6.35 mm (1/4 in) gradients intersect at a span of approximately 4100 mm (13 ft 6 in) with a deflection of
23.5 mm (0.925 in). Therefore, the following guideline is suggested:

At design wind loads, deflections of building cladding framing members for spans up to 4110 mm (13 ft 6 in) shall be limited to
L/175. For spans greater than 4110 mm (13 ft 6 in), but less than 12 m (40 ft), deflections at design wind loads shall be limited to the
more conservative value of L/240 + 6.35 mm (1/4 in). “L” denotes clear span, i.e., length of member between reaction points. Spans
exceeding 12 m (40 ft) may require additional constraints and should be analyzed by the responsible design professional on a case-
by-case basis.

Other factors exist which could require a deflection limit less than that allowed by the above framing formulae. The following is a
partial list of those factors:

4.1 The anticipated movement of the framing members must not exceed the movement capabilities of adjoining sealants.

4.2 The anticipated movement of the framing members may need to be further limited to accommodate the properties and location of
interior finishes (e.g. plaster, drywall, etc.)

4.3 The movement of the framing members must not cause disengagement of applied snap covers or trim.

4.4 The design of the framing members must accommodate differential movement in adjacent framing members such as might occur
at jambs, parapets, unusual geometries and other similar conditions.

AAMA TIR-A11-15 Page 2

You might also like