A METHOD OF FORMING A PLURALITY OF ELONGATE TRUSS
COMPONENTS FOR A METAL ROOF TRUSS
FILED OF THE INVENTION
The present invention relates generally to a metal roof
truss and relates particularly, though not exclusively, to
a method of forming a metal roof truss and its components
including elongate stiffening webs and chord members.
SUMMARY OF THE INVENTION
According to one aspect of the present invention there is
provided a metal roof truss comprising:
a Lower chord member at opposite ends being connected
to respective ones of a pair of upper chord members; and
a plurality of compression webs at opposite ends being
connected to the lower chord member and one of the upper
chord members, respectively;
the compression webs and the chords being of channel
section profile having a web and an opposing pair of
flanges each having a free edge portion turned inwardly to
extend over the web, and being interconnected so that the
truss is generally planar with the compression webs and the
chord members being orientated to face in the same
direction;
wherein each of the compression webs are configured at
their opposite ends so that a portion of the web protrudes
beyond its flanges, and wherein the compression webs are
connected to respective chords by the protruding web
portions mounting flush on corresponding webs of the chord
members and edge surfaces of the flanges adjacent the
protruding web portions bearing against respective ones
of the flanges of the chords to which they are connected,
and being secured in that position by at least
one fastener extending through each protruding web portion
and the web portion of the chord member to which it is
flush mounted.
It has been found that this engagement or contact of the
flanges of the compression web with the upper or lower
chord member increases the structural performance of the
roof truss.
Preferably at least one of the flanges of the lower chord
member at its opposing ends is cut or otherwise preformed
to engage or contact respective of the upper chord
members.
Preferably the chord members and/or the compression webs
are in sectional profile asymmetric wherein one of the
opposing flanges is of a reduced height compared to the
other of said flanges. In one form, a pair of the chord
members and/or compression webs are designed to interlock
with one another to form a closed section. In one
embodiment the web and/or the flanges of the chord members
and/or the compression webs include a longitudinally
extending stiffening rib.
Preferably of the chord members and the compression webs
include preformed holes which are mutually align on
interconnecting of the members for fixing of the roof
truss. More preferably the chord members and the
compression webs are fixed together via one or more
fasteners which engage the preformed and aligned holes.
^ Fasteners commercially available in Australia under the
trade mark TRUSSTITE are particularly suited.
Preferably, the pair of upper chord members are at an
upper end connected to one another with an apex plate.
More preferably the apex plate is elongate and at least
one of its opposing longitudinal edges includes a
stiffening flange. In one embodiment the stiffening flange
includes a lip formed orthogonal to the apex plate and the
apex plate is fixed to the chord members via a plurality
of apex fasteners.
According to another aspect of the present invention there
is provided a method of forming a plurality of elongate
truss components for a metal roof truss, the truss
components being stiffening webs and/or chord members of
the truss and said method comprising the steps of:
forming one or more pairs of opposing notches in
elongate strip metal; and
roll forming the elongate strip metal to form the
truss components with a channel section profile, the truss
components being continuous and a juncture between the
adjoining truss components being defined by a said pair of
opposing notches and incorporating a frangible connection
permitting separation of adjoining truss components after
roll forming.
Preferably, each channel shaped truss component includes a
web and a pair of opposing flanges, and wherein the
respective flanges of adjoining truss components are
separated by a respective notch of an opposing pair of
notches such that the adjoining truss components are
interconnected solely by their webs. Generally the
frangible connection is provided at the juncture of a web
adjoining the webs and/or the chord members. More
preferably the separation is effected by manipulation only
without cutting or separation tools.
Preferably said step of forming the notches involves
punching or stamping the strip metal.
Preferably the method also comprises pre-forming fastener
holes in opposing ends of the stiffening web and/or the
chord member. More preferably the fastener holes are
prepunched in a web of the channel section profile.
According to a further aspect of the present invention
there is provided a method of forming a metal roof truss,
said method comprising of steps of:
providing processing means and printing means being
arranged to operatively communicate with one another;
inputting design information to the processing means
wherein the metal roof truss configuration and fixing
details are calculated; and
printing at least the fixing details on components of
the metal roof truss.
Preferably the fixing details are printed on the component
of the roof truss to which the detail applies. More
preferably the fixing details are printed on elongate
stiffening webs and/or chord members of the metal roof
truss.
Preferably, printing of the fixing details involves ink-
jet printing on strip metal from which the roof truss
component is thereafter to be roll formed.
Preferably, the inputting of design information involves
inputting dimensional and loading data pertaining to a
building structure on which the metal roof truss is to be
erected.
According to yet another aspect of the present invention
there is provided a method of forming a metal roof truss,
said method comprising the steps of:
providing processing means to which design
information is inputted for the calculation of the roof
truss configuration, and means for notching metal strip
from which components of the metal roof truss are to be
roll formed, said notching means being arranged to
operatively communicate with the processing means; and
notching the metal strip utilising the notching means
wherein opposing pairs of notches are formed in the metal
strip, said pairs of notches defining a frangible
connection between adjacent components of the metal roof
truss and being shaped dependent on the roof truss
configuration.
According to yet a further aspect of the present invention
there is provided an apparatus for forming a metal roof
truss, said apparatus comprising:
processing means to which design information is
inputted for the calculation of the roof truss
configuration; and
means for notching metal strip from which components
of the metal roof truss are to be roll formed, said
notching means being arranged to operatively communicate
with the processing means wherein opposing pairs of
notches are formed in the metal strip, said pairs of
notches defining a frangible connection between adj acent
components of the metal roof truss and being shaped
dependent on the roof truss configuration.
Generally the adjacent components include one or more
elongate stiffening webs and/or chord members.
Preferably, the apparatus also comprises a roll former
operatively coupled to the notching means whereby the
prenotched metal strip is roll formed into a channel
section profile.
In yet a further aspect, the present invention provides a
plurality of elongate truss components, the components
being formed from a continuous strip of metal and adjoined
in end to end relationship, a juncture between the
adjoining truss components being defined by a pair of
opposing notches and incorporating a frangible connection
permitting separation of the adjoining components, wherein
the notches are shaped and positioned dependant on the
truss configuration, so that on separation of the
adjoining truss components at the frangible connections,
the components are sized and shaped for assembly of said
truss.
BRIEF DESCRIPTION OF THE DRAWINGS
In order to achieve a better understanding of the nature
of the present invention a preferred embodiment of a metal
roof truss together with the various other aspects of the
invention will now be described, by way of example only,
with reference to the accompanying drawings in which;
Figure 1 is a perspective view of a metal roof truss;
Figure 2 is an exploded perspective view of the metal
roof truss of Figure 1;
Figure 3 is front and rear detailed views of a web to
chord connection of the roof truss of Figure 1,-
Figure 4 is front and rear detailed views of a heel
¦" connection of the metal roof truss of Figure 1;
r .
Fig-are 5 is a perspective view of pre-notched strip
steel of roof truss components prior to roll forming;
Figure 5 is a perspective view of an apex place of zhe
metal roof truss of Figure 1; and
Figure 7 is a block flow diagram of the general
process steps involved in forming a metal roof truss
according to an embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in Figure 1 there is a metal roof truss 10
comprising a lower chord member 12 at opposing ends being
connected to respective of a pair of upper chord members
14 and 15. The metal roof truss 10 also comprises a
plurality of elongate stiffening web3 such as 18 and 2 0
which at opposing ends are connected to the lower chord
member 12 and one of the upper chord members 14
respectively. In this example one of the stiffening webs
is a compression web 18 whereas the other stiffening web
is a tension web 20. The metal roof truss 10 of this
embodiment is shaped generally triangular wherein adjacent
ends of the upper chord members 14 and 16 are connected at
an apex connection 22. Opposite ends of the upper chord
members 14 and 16 are connected to opposing ends of the
lower chord member 12 at respective heel connection such
as 24. However, it should be appreciated that the metal
roof truss configuration may vary from that described
whilst remaining within the ambit of the invention, for
example the bottom chord may include more than one chord
member and similarly the pair of upper chord members may
be extended to multiple chords.
As shown in Figure 2 the lower and upper chords 12 to 16
together with the stiffening webs such as 18 and 2 0 are
cold roll formed from strip steel into a channel section
profile including a web 2 6 and an opposing pair of flanges
such as 28 and 30. The flanges 28 and 30 include free edge
portions which are turned inwardly toward one another. The
bottom and top chords 12 to 16 together with the
stiffening webs 18 and 20 are fabricated from relatively
light gauged strip steel typically of a thickness of
0.75mm such as that commercially available in Australia.
According to one aspect of the invention opposing ends of
the stiffening webs such as 18 and 20 are configured
wherein opposing flanges such as 28 and 3 0 of the
respective stiffening web 18 or 20 engage the lower chord
12 and one of the upper chords such as 14.
This is best illustrated in Figure 3 where according to
one embodiment the engagement or contact of the flanges
such as 2 8 and 3 0 of the compression web 18 increases the
structural performance of the roof truss 10. The lower and
upper chords 12 to 16 together with the stiffening web
such as 18 and 2 0 are arranged in the same plane and the
respective webs such as 2 6 of the stiffening webs such as
18 and the chord members such as 12 are flush with one
another. Importantly, the flanges such as 28 and 30 of the
compression webs 18 are at opposing ends cut or otherwise
preformed to engage or contact the lower and upper chords
12 and 14, respectively. The "depth" to which the flanges
such as 2 8 and 3 0 are cut is dictated by the orientation
of the stiffening web relative to the chord member such as
18 and 12 respectively.
The stiffening webs such as 18 and 20 and the lower or
upper- chord members 12 to 16 include preformed holes such
as 32 and 34 which are mutually aligned for fixing of the
roof truss 10. Screw fasteners such as those commercially
available in Australia under the trade mark TRUSSTITE
which have a relatively coarse thread, engage the aligned
holes such as 32 or 34 so as to fix the stiffening web to
the lower chord 18 and 20 respectively. The aligned holes
such as 32 and 34 are generally prepunched in the strip
steel from the chord member such as 12 or stiffening web
18 is roll formed.
As shown in Figure 4 the opposing flanges such as 2 8 and
3 0 of the upper chord member 14 are similarly preformed at
one end to form the heel connection 24. The flanges 28 and
3 0 are cut or otherwise preformed at opposing ends of the
upper chord member 14 wherein the flanges 2 8 and 3 0 engage
or contact the lower chord 12. The lower and upper chords
12 and 14 also include preformed and mutually aligned
holes such as 3 8 which is engaged by a TRUSSTITE or other
fastener for fixing of the lower and upper chords 12 and
14. The engagement or contact of the flanges 2 8 and 3 0 of
the upper chord 14 with a corresponding flange such as 2 8
of the lower chord 12 further increases the structural
performance of the roof truss 10. The "depth" to which the
flanges 2 8 and 3 0 of the upper chord 14 or 16 are cut or
otherwise preformed is dictated by the configuration of
the roof truss 10 and in particular the angle of the upper
chord member 14 or 16 relative to the lower chord 12.
The channel section chords 12 to 16 and stiffening webs
such as 18 and 2 0 of this embodiment are asymmetric in
sectional profile. One of the opposing flanges such as 28
is of a reduced height compared to the other of said
flanges such as 3 0 wherein a pair of channel section
chords or webs such as 12 or 18 are designed to interlock
with one another to form a chord or stiffening web of a
closed section. The chords 12 to 16 and/or stiffening webs
18 and 2 0 may include one or more longitudinally extending
stiffening ribs. Preferably, the stiffening ribs are
formed in the web such as 2 6 of the channel section.
According to another aspect of the invention there is a
method of forming elongate stiffening webs such as 18 and
20 and/or chord members such as 12 to 16. As shown in
Figure 5 this embodiment of the method involves preforming
one or more pairs of opposing notches such as 3 6 and 3 8 in
elongate strip steel 40. The pair of opposing notches such
as 3 6 and 3 8 provide a frangible connection at the
juncture of, in this example, adjacent stiffening webs
such as 18 and 20. The preformed opposing notches 36 and
3 8 are shaped so that:
i) the adjacent stiffening webs 18 and 20 of this
embodiment can, after roll forming of the section, be
separated by manipulation or by repeated bending of the
adjacent webs 18 and 2 0;
ii) opposing flanges such as 28 and 3 0 of the respective
stiffening web 18 or 2 0 contact the lower chord 12 or
upper chord 14 or 16 when the roof truss 10 is erected.
In this example the opposing notches such as 3 6 and 3 8
extend part way into the web such as 26 of the
corresponding stiffening web 18 or 20. Thus, the web 26 is
sufficiently weakened at the juncture of the stiffening
webs 18 and 20 to allow separation of the stiffening webs
18 and 20. However, the frangible connection is
sufficiently strong to retain the connection between
adjacent metal roof components such as the stiffening webs
18 and 2 0 during roll forming. Therefore, the various
components of the metal roof truss such as the stiffening
webs 18 and 2 0 can be fabricated as a "string". For
example, the stiffening webs such as 18 and 2 0 together
with the other stiffening webs of the roof truss 10 can be
fabricated as a single "string" and separated prior to
erection of the metal roof truss 10. Similarly, for
relatively small trusses the upper and lower chords such
as 12 to 16 may be linked in a "string". This increases
the speed at which the metal roof truss components can be
fabricated, reduces the risk of losing components, and
facilitates the erection of the metal roof truss such as
10.
The prenotched chords such as 12 to 16 and stiffening webs
18 and 2 0 may also be preholed to facilitate subsequent
assembly. In this instance fastener holes such as 32 and
3 4 are formed in opposing ends of the respective
stiffening webs such as 18 and 22 together with mutually
aligned fastener holes formed in this example in the
bottom chord 12. The fastener holes such as 32 and 34 are
prepunched in the web such as 2 6 of the respective roof
truss component either before, after, or during
prenotching of the strip steel such as 40. The prenotched
and preholed strip 40 is then cold roll formed into the
channel section depicted in Figure 2. The roll former is
relatively low cost and "dumb" whereas the prenotching and
preholing of the strip steel is to be effected with a
relatively high degree of precision. This ensures that on
fixing and erection of the metal roof truss such as 10 the
flanges such as 2 8 and 3 0 of for example the stiffening
webs 18 and 2 0 bear against the lower and upper chords 12
and 14 respectively.
Figure 6 illustrates an apex plate 42 to be included in
the apex connection 22. The apex plate 42 is elongate and
includes a stiffening flange 44 along one of its
longitudinal edges. The stiffening flange 44 is defined by
a lip which is bent at right angles to the apex plate 42.
The apex plate 42 is screwed or otherwise fixed to the
webs of adjoining top chords 14 and 16. The apex plate 42
is oriented generally horizontally with the stiffening
flange 44 located between the top chords 14 and 16 and
directed inwardly of the roof truss 10. The apex plate 42
is suited to a range of apex connections up to an angle of
around 4 0 degrees. The apex plate 42 includes a plurality
of preformed holes such as 4 6 arranged for fixing of the
apex plate 42 to the upper chords 14 and 16 and the webs
such as 20.
Figure 7 is a block flow diagram of the various steps
involved in design and fabrication of a metal roof truss
such as that described in the preceding paragraph. The
general steps involved in forming the metal roof truss 10
are as follows:
i) design information is inputted to a processor which
is configured to output control information to a
prenotching and preholing apparatus;
ii) strip steel is fed to the prenotching and preholing
apparatuses which form the strip steel according to
the control information from the processor;
iii) fixing details generated and outputted by the
processor are printed on the prenotched and preholed
strip steel; and
iv) the strip steel is roll formed in a conventional
relatively low cost roll former.
The fixing details are preferably printed on the component
such as the chord 12 or stiffening web 16 to which the
detail applies. For example, the stiffening web 18 may
include the fixing details or instructions wherein it
requires two fasteners at each end to be secured to the
appropriately designated upper and lower chord.
Additionally, the roof truss component may include post-
assembly validation information for checking by a third
party. The marking of components is also intended to
- assist with the design integrity of the roof truss and the
speed at which it is assembled.
The processor includes software which operates in a CAD
"environment" and determines the preferred configuration
of the metal roof truss depending on the dimensional and
loading data pertaining to the building structure.
Additionally, the program accurately determines the
prenotching and preholing requirements dependent on the
relative angles of the various roof truss components. Th.
is particularly important in ensuring that, for example,
the flanges of the stiffening webs contact the upper and
lower chords.
Those skilled in the art will appreciate that the
invention described herein is susceptible to variations
and modifications other than those specifically describe
For example, the sectional profile of the stiffening web
and/or chord members may vary provided the structural
advantages of the opposing flanges engaging the chord
members are achieved. The prenotching of the strip steel
may vary provided a frangible connection is provided
between adjacent components, such as stiffening webs, of
the metal roof truss.
All such variations and modifications are to be considei
with the scope of the present invention the nature of
which is to be determined from the foregoing descriptior
WE CLAIM:
1. A method of forming a plurality of elongate truss
components for a metal roof truss, the truss components
being stiffening webs and/or chord members of the truss and
said method comprising the steps of:
forming one or more pairs of opposing notches in
elongate strip metal; and
roll forming the elongate strip metal to form the
truss components with a channel section profile, the truss
components being continuous and a juncture between the
adjoining truss components being defined by a said pair of
opposing notches and incorporating a frangible connection
permitting separation of adjoining truss components after
roll forming.
2. A method as claimed in claim 1, wherein each channel
shaped truss member has a web and a pair of opposing
flanges, and wherein the respective flanges of adjoining
truss components are separated by a respective notch of an
opposing pair of notches such that the adjoining truss
components are interconnected solely by their webs.
3. A method as claimed in any of claim 1 or 2, wherein
the connection is frangible to allow separation of adjoining
truss components by manipulation only without cutting or by
separation tools.
4. A method as claimed in any of the preceding claims,
wherein the step of forming the notches involves punching
or stamping the strip metal.
5. A method as claimed in any of the preceding claims,
involving the step of forming fastener holes in the
elongate strip metal.
6. A method as claimed in claim 5, wherein the
fastenerholes are punched in the webs of the truss
components.
7. A method as claimed in any of the preceding claims,
involving the steps of:
establishing a desired roof truss configuration;
and
establishing an arrangement of notches on the strip
metal to form truss components that are suitable for use in
the desired roof truss configuration; wherein
said step of forming one or more pairs of opposing
notches in the elongate strip metal notches the metal strip
according to the established arrangement.
8. A method as claimed in claim 7, involving the steps of:
establishing the fixing details for the truss
components for the desired roof truss configuration; and
printing information relating to the fixing details on
the truss member.
9. A method as claimed in claim 8, wherein the fixing
details are printed on the component of the roof truss to
which the detail applies.
10. A method as claimed in claim 9, wherein the fixing
details are printed on elongate stiffening webs and/or
chord components of the truss components.
11. A method as claimed in any of claims 8 to 10, wherein
printing on the fixing details involves ink-jet printing on
strip metal from which the roof truss components is
thereafter to be roll formed.
12. A method as claimed in any of claims 7 to 11, wherein
the desired roof truss configuration is established by a
computer processor in response to design information
processed by said computer processor.
13. A method as claimed in claim 12, wherein the design
information has dimensional and loading data pertaining to
a building structure incorporating the metal roof truss.
14. A method as claimed in claim 12, wherein the computer
processor is arranged to operatively communicate with
printing means, and the method involves the steps of :
inputting design information to the computer processor
wherein the metal roof truss configuration and fixing
details are calculated; and
printing at least information relating to the fixing
details on components of the metal roof truss.
15. A method as claimed in claim 14, wherein the fixing
details are printed on elongate stiffening webs and/or
chord members of the metal roof truss.
16. A method as claimed in any of claims 14 or 15, wherein
the inputting of design information involves inputting
dimensional and loading data pertaining to a building
structure on which the metal roof truss is to be erected.
17. A method of forming a plurality of elongate truss
components for a metal roof truss, said method comprising
the steps of:
providing processing means to which design information
is inputted for the calculation of the roof truss
configuration, and means for notching metal strip from
which components of the metal roof truss are to be roll
formed, said notching means being arranged to operatively
communicate with the processing means; and
notching the metal strip utilising the notching means
wherein opposing pairs of notches are formed in the metal
strip, said pairs of notches defining a frangible
connection being shaped dependent on the roof truss
configuration.
18. A method as claimed in claim 17, wherein the adjacent
components have one or more elongate stiffening webs
and/or chord members.
19. An apparatus for forming a plurality of elongate truss
components for a metal roof truss, said apparatus
comprising;
processing means to which design information is
inputted for the calculation of the roof truss
configuration; and
means for notching metal strip from which
components of the metal roof truss are to be roll formed,
said notching means being arranged to operatively
communicate with the processing means wherein opposing
pairs of notches are formed in the metal strip, said pairs
of notches defining a frangible connection between adjacent
components of the metal roof truss and being shaped
dependent on the roof truss configuration.
20. An apparatus as claimed in claim 19, wherein the
adjacent components include one or more elongate stiffening
webs and/or chord members.
21. An apparatus as claimed in either claim 19 or 20,
having a roll former operatively coupled to the notching
means whereby the prenotched metal strip is roll formed
into a channel section profile.
22. A plurality of elongate truss components, the
components being formed from a continuous strip of metal
and adjoined in end to end relationship, a juncture between
the adjoining truss components being defined by a pair of
opposing notches and incorporating a connection permitting
separation of the adjoining components, wherein the notches
are shaped and positioned dependant on the truss
configuration, so that on separation of the adjoining truss
components at the connections, the components are sized and
shaped for assembly of said truss.
23. A plurality of elongate truss components as claimed in
claim 22, wherein the components are channel shaped and
include a web and a pair of opposing flanges, wherein the
flanges of adjoining truss components are separated by a
respective notch of an opposing pair of notches so that the
adjoining truss components are interconnected solely by
their webs.
24. A plurality of elongate truss components as claimed in
claim 23, wherein the frangible connection between
adjoining components is located on the web intermediate
margins of the notches, so that on separation of the truss
components, each component is configured so that an end of
each component includes a portion of the web that protrudes
beyond its flanges.
25. A plurality of elongate truss components as claimed in
claim 23 or 24, wherein edge surfaces of the flanges formed
on notching of the strip metal form bearing surfaces
arranged to bear against other truss components on assembly
of the truss.
26. A plurality of elongate truss components as claimed in
any of claims 22 to 25, wherein the truss components have
preformed holes for receiving fasteners to secure the truss
components together on assembly of the truss.
27. A plurality of elongate truss components as claimed in
any of claims 22 to 26, wherein the components have
information relating to fixing details of the components
for the desired truss configuration.
28. A plurality of elongate truss components as claimed in
any of claims 22 to 27, wherein the frangible connection is
configured so as to allow separation of adjoining truss
components by manipulation only without cutting or
separation tools.
29. A metal roof truss formed from a plurality of elongate
truss components as claimed in any of claims 22 to 28, the
components of the truss comprising:
a lower chord member at opposite ends being connected
to respective ones of a pair of upper chord members; and
a plurality of compression webs at opposite ends being
connected to the lower chord member and one of the upper
chord members, respectively;
the compression webs and the chords being of channel
section profile having a web and an opposing pair of
flanges each having a free edge portion turned inwardly to
extend over the web, and being interconnected so that the
truss is generally planar with the compression webs and the
chord members being orientated to face in the same
direction;
wherein each of the compression webs is configured at
its opposite ends so that a portion of the web protrudes
beyond its flanges, and wherein the compression webs are
connected to respective chords by the protruding web
portions mounting flush on corresponding webs of the chord
members and edge surfaces of the flanges 30 adjacent the
protruding web portions bearing against respective ones of
the flanges of the chords to which they are connected, and
being secured in that position by at least one fastener
extending through each protruding web portion and the web
portion of the chord member to which it is flush mounted.
30. A metal roof truss as claimed in claim 29, wherein the
chord members and the compression webs are of a
substantially identical sectional profile.
31. A metal roof truss as claimed in claim 29 or 30,
wherein the chord members and the compression webs are in
sectional profile asymmetric wherein one of the opposing
flanges is of a reduced height compared to the other of
said flanges.
32. A metal roof truss as claimed in any of claims 29 to
31, wherein the web and/or flanges of the chord members
and/or compression webs has/have a longitudinally extending
stiffening web.
33. A metal roof truss as claimed in any of claims 29 to
32, wherein the web of the chord members and the protruding
web portion of the compression webs each have preformed
holes which are mutually aligned and which receive the one
or more fasteners used to secure the compression webs to
the respective chord members.
34. A metal roof truss as claimed in any of claims 29 to
33, wherein the pair of upper chord members are at an upper
end connected to one another with an apex plate.
35. A metal roof truss as claimed in claim 34, wherein the
apex plate is elongated and at least one of its opposing
longitudinal edges includes a stiffening flange.
36. A metal roof truss as claimed in claim 35, wherein
the stiffening flange has a lip formed orthogonal to the
apex plate and the apex plate is fixed to the chord member
via a plurality of apex fasteners.
37. A metal roof truss as claimed in any one of claims 29
to 36, wherein a pair of the chord members and/or
compression members are designed to interlock with one
another to form a closed section.

A method of forming a plurality of elongate truss
components for a metal roof truss, the truss components
being stiffening webs and/or chord members of the truss and
said method comprising the steps of:
forming one or more pairs of opposing notches in
elongate strip metal; and
roll forming the elongate strip metal to form the
truss components with a channel section profile, the truss
components being continuous and a juncture between the
adjoining truss components being defined by a said pair of
opposing notches and incorporating a frangible connection
permitting separation of adjoining truss components after
roll forming.