Cullen Technical Guide 2024

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HMT High Movement Timber Frame Wall Tie

Product code

Minimum cavity (mm)

Maximum cavity (mm)

HMT–50

45

65

HMT–50

Tested Values

Compression

Y m

Tension

Y m

Nail end (as received)

1705

895 (nail withdrawal)

1.3

Masonry end

2376

1.15 (buckling of tie – steel failure)

2176 (masonry withdrawal)

3

Based on the following criteria the following calculations have been done:

In the following examples a factored windload of 1.65kN/m 2 is suggested

Partial factor for variable action

1.5

Combined pressure coefficient

1.1

Peak velocity pressure

= 1.0 kN/m 2

Applied wind load on gable panel

= 1.5 x 1.1 x 1.0

= 1.65 kN/m 2

Failure

Test Result (kN)

Y m

kmod

Result x kmod / Y m (kN)

Compression

1.705

1.15

0.9

1.3343

Tension

0.895

1.3

0.9

0.6196

Tension

2.176

3

0.9

0.6528

Compression

2.376

1.15

0.9

1.8595 0.6196

*A short term action (kmod value – 0.9) has been used. An instantaneous action (kmod value – 1.1) may be used.

Maximum net surface wind pressure for the HMT–50

Product Code

Vertical Tie Spacing (mm)

225

300

375

450

Stud Centres (mm)

600

600

600

600

Maximum Net Surface Wind Pressure

kN/m 2

ties/m 2

kN/m 2

ties/m 2

kN/m 2

ties/m 2

kN/m 2

ties/m 2

HMT–50

4.59

7.4

3.41

5.5

2.73

4.4

2.29

3.7

1000/225 = 4.4444 4.4444x(1000/600) = 7.4 ties/m 2

1000/300 = 3.3333 3.3333x(1000/600) = 5.5 ties/m 2

1000/375 = 2.6666 2.6666x(1000/600) = 4.4 ties/m 2

1000/450 = 2.2222 2.2222x(1000/600) = 3.7ties/m 2

Lowest failure (with Ym & kmod applied)

0.6196 x 7.4 = 4.59kN/m 2

0.6196 x 5.5 = 3.41kN/m 2

0.6196 x 4.4 = 2.73kN/m 2

0.6196 x 3.7 = 2.29kN/m 2

Peak velocity pressure (kN/m 2 )

2.78

2.07

1.65

1.39

Based on the above values this could be worked backwards Provide a maximum wind load for 3.7 ties/m 2 = (2.29/1.1/1.5) = 1.39kN/m 2 peak velocity pressure

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