Note: Descriptions are shown in the official language in which they were submitted.
CA 02467554 2004-05-19
a.
ROOF ACCESS DEVICE AND METHOD OF USE
FIELD OF THE INVENTION
The present invention relates to a roof access device for providing
access to a sloped roof, and more particularly relates to a method of use of
the
device for anchoring a personal fall restraint lifeline on a sloped roof.
BACKGROUND
When inspecting or performing work on conventional wooden truss
sloped roofs it is common practice to access the roof by placing a ladder
against the
edge of the roof for climbing onto the roof. Leaning ladders against the edges
of
roofs commonly causes damage to eaves in the form of denting or chipping of
paint.
When walking about on a sloped roof it is often desirable to tether
persons to anchors commonly placed at the ridge of the roof. US patent
5,287,944
to Woodyard discloses one example of a ridge mounted roof anchor. A common
problem with conventional ridge anchors exists in that it is not possible to
secure the
lifeline of the worker to the ridge anchor without first walking up the roof
from the
ladder to the ridge while not being tethered. Thus even when it is the
intention to
make use of a lifeline or fall restraint type device, accidents may occur
causing
damage or injury before the lifeline or restraint can even be secured.
SUMMARY
According to one aspect of the present invention there is provided a
roof access device for use on a sloped roof supported by trusses, the device
comprising:
a housing having open top and bottom ends for permitting access of a
person therethrough;
a cover member for selectively enclosing the open top end of the
housing; and
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anchoring means for securing the housing between an adjacent pair of
the trusses.
According to a second aspect of the present invention there is provided
a roof access device for use on a sloped roof supported by trusses, the device
comprising:
a housing having open top and bottom ends for permitting access of a
person therethrough;
a cover member for selectively enclosing the open top end of the
housing;
anchoring means for securing the housing between an adjacent pair of
the trusses; and
a lifeline anchor mounted on the housing for securing a personal fall
restraint lifeline thereto.
According to a third aspect of the present invention there is provided a
roof construction for a sloped roof comprising:
a plurality of trusses;
a housing having open top and bottom ends and which is secured
between an adjacent pair of the trusses for permitting access of a person
therethrough;
roofing material spanning the trusses about the housing;
a cover member for selectively enclosing the open top end of the
housing.
The roof access device provides access to a sloped roof between a
pair of adjacent trusses such that the housing can be located adjacent the
ridge or
any other convenient location on the roof. The roof may then be accessed by
inspectors or workers without requiring use of a ladder against the eaves of
the roof
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normally causing damage when conventionally accessing the roof. Providing
access
to the roof which can be placed adjacent the ridge also permits a ridge anchor
to be
located in proximity to the access point to the roof so that a lifeline or
fall restraint
can be anchored thereon before a person even steps onto the roof. In a
preferred
embodiment, the anchor for the lifeline is part of the roof access device
itself.
The lifeline anchor is preferably supported in a wall of the housing
oriented perpendicularly to the anchoring means for securing the housing to
the
trusses.
When the cover member is pivotally supported on the housing by a
hinge, the lifeline anchor is preferably supported in a wall of the housing
which is
oriented perpendicularly to the hinge.
When the housing is generally rectangular in shape including a pair of
short sides and a pair of long sides, the anchoring means preferably comprises
bolt
apertures for receiving bolts to secure to the trusses located in the long
sides of the
housing.
The cover member may include an internal lock mechanism preventing
the cover member from being opened by unauthorized persons at an external side
of
the cover member.
The housing preferably snugly fits between the adjacent pair of trusses
when the trusses are supported at a conventional spacing for securement to the
trusses using threaded fasteners.
The cover member may be pivotally supported on the housing by a
hinge which is oriented perpendicularly to a ridge of the sloped roof.
A ladder may be supported in an attic space defined by the trusses
spanning between a floor of the attic space and the open bottom end of the
housing.
According to a further aspect of the present invention there is provided
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a method of anchoring a personal fall restraint lifeline to a sloped roof
supported by
trusses, the method comprising:
providing a roof access device comprising a housing having open top
and bottom ends and a cover member for selectively enclosing the open top end
of
the housing;
securing the housing between an adjacent pair of the trusses;
mounting a lifeline anchor in proximit)r to the open top end of the
housing;
accessing the roof through the open top and bottom ends of the
housing; and
securing the lifeline to the lifeline anchor'.
The method may include locating the lifeline anchor on a wall of the
housing lying perpendicular to a different wall of the housing which is
secured to one
of the adjacent pair of the trusses,
The method may also include locating the lifeline anchor on a waN of
the housing lying parallel to a ridge of the root.
Preferably a pair of horizontal supports are installed on said adjacent
pair of trusses respectively which are abutted against the open bottom end of
the
housing.
At least a portion of a king post is preferably installed in said adjacent
pair of trusses between which the housing is secured for securement to the
housing.
When using the roof access device, preferably one°s lifeline is
secured
to the lifeline anchor prior to stepping out onto the roof.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings, which illustrate an exemplary
embodiment of the present invention:
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Figure 1 is a front elevational view of the roof access device shown
installed on a roof.
Figure 2 is a front elevational view of a first roof access device and a
side elevational view of a second roof access device, both shown with roofing
material removed from the surrounding trusses.
Figure 3 is a perspective view of the roof access device.
Figure 4 is a schematic inside elevational view one of the trusses
supporting the device thereon.
DETAILED DESCRIPTION
Referring to the accompanying drawings, there is illustrated a roof
access device generally indicated by reference numeral 10.
The device 10 is particularly suited for use on sloped roofs 12 formed
by wooden trusses 14 supported spaced apart with one another and joined at
their
apex by a tie beam 16 defining the ridge of the completed roof structure. Each
truss
includes a pair of principal rafters 18 forming opposing slaped surFaces of
the roof
and a plurality of struts 20 spanning the height of the truss at spaced
positions
between the ends thereof. The truss and the illustrated embodiment is of a
Fink or
W design as opposed to a King post design having a vertical post at the apex.
When suitable roofing material including plywood, tar paper, shingles and the
like
spans the trusses, an enclosed attic space 22 is defined within the area
across
which the trusses span.
The device 10 generally comprises a rectangular steel housing 24
comprising four wall, an open top end 26 and an open bottom end 28. A through
opening extends between the open top end and the open bottom end suitable for
a
person to climb therethrough.
The narrow dimension of the housing 24 is suitably sized for fitting
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snugly between two adjacent trusses which are supported at a conventional
spacing.
The opposing pair of longer walls of the housing 24 are bolted at spaced
positions to
the trusses respectively. Each of the long sides of the housing 24 includes
plural
bolt apertures 30 at spaced positions longitudinally across a bottom end of
the
housing for adjustably bolting to the trusses at various positions depending
upon the
slope of the roof. One of the apertures is centrally located with remaining
apertures
being spaced apart near the short sides of the housing for fastening to the
principal
rafters of the truss respectively. The plurality of longitudinally spaced
apertures
readily permits the housing to be bolted between principle rafters of adjacent
trusses
far any slope of roof between a flat roof and a 12,112 slope having a 45
degree
incline.
The roof is built with a gap in the tie beam 1 fi along the ridge between
two adjacent trusses. A reinforcing sheet of plywood 32 is supported on the
outer
sides 34 of the trusses supporting the device thereon which face away from the
device. If a King post is not already present in the truss, a reinforcing King
post 36 is
mounted within the truss to span approximately twE:nty inches below the apex
for
overlapping the plywood reinforcing sheet 32 fitted along side the truss
adjacent the
apex thereof. The sheet 32 has a height of approximately two feet at the apex
with a
base which is approximately four feet in length to~ provide an adequate
support
surface for securement of the long sides of the housing 24 directly thereon in
abutment.
Horizontal supports 38 in the form of two by fours are supported
symmetrical with the apex on confronting inner sides 40 of the pair of trusses
mounting the housing 24 of the device therebetween. The horizontal supports
are
mounted approximately a foot below the apex for resting the bottom edges of
the
housing thereon in such a manner that the device projects upwardly above the
peak
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with all walls of the housing beginning below the surface of the roof at a
point of
intersection therewith to extend upwardly above the surface of the roof. The
roofing
material spanning the trusses includes a suitable opening therein through
which the
housing of the device projects so that the roofing material surrounds the
device and
is sealed against the walls of the housing by suitable flashing and any other
conventional sealing materials used in roofing.
A cover member 42 is pivotally supported on the housing for
movement between a closed position spanning across the open top end of the
housing in sealing engagement therewith and an open position in which the open
top
end is clear of obstruction. The cover member is hinged along one of the long
sides
of the housing so as to have an axis which is perpendicular to a longitudinal
direction
of the tie beam 16 defining the ridge of the roof. The hinge 44 co-operates
with a
sliding brace mechanism 46 at each end of the housing. In a fully extended
position,
the brace can be locked with the cover member being oriented vertically,
perpendicular to the open top end of the housing. Disengaging the braces 46
permits the cover member to be pivoted downwardly for sealing engagement with
the housing by conventional sealing members.
The cover member 42 includes an internal handle 48 mounted on an
inner surface thereof and an internal lock 50 which us operated and securable
from
an internal side of the cover member to restrict access by unauthorized
persons to
the interior of the device when the cover member is closed and the lock is
engaged.
A lifeline anchor 52 is mounted centrally within each of the short sides
of the walls of the housing 24 of the device. The short sides mounting the
anchor
therein are oriented parallel to the ridge of the roof offset on opposing
sides thereof
and are oriented perpendicularly to the wall supporting the hinge of the cover
member and bolt holes for securerr~ent to the trusses therein. Each anchor
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comprises an eye bolt with a 5I8 inch shaft secured at an inner end to an
internal
reinforcing channel 54 which spans the interior of the housing on the opposing
short
sides for added structural integrity A cover flange 56 is provided on an
external
surface of each of the short walls parallel to the ridge so that the flanges
are
positioned directly above the respective lifeline anchors 52. Each cover
flange 56 is
generally an inverted V-shape to protect the respective anchors from the
elements
and from damage due to impacts and the like.
Within the attic space 22, a ladder 58 is supported to span between the
access panel in the ceiling below the attic space and the opening through the
housing of the device 10. The housing is located between an adjacent pair of
trusses directly adjacent the roof access panel to the: attic space with a
platform 60
being provided along a floor of the attic space at the base of the ladder 58
to span
between the base of the ladder and the roof access panel to the attic for
convenience in reaching the roof access device 10.
In use the external roof structure can be accessed by climbing through
the attic space and subsequently through the open top and bottom ends of the
roof
access device when the cover is opened. To open the cover, the lock 50 is
first
disengaged and the braces are then locked with the cover member in a vertical
orientation. A personal fall restraint lifeline is then secured to the
lifeline anchor 52
on a side of the housing which faces the roof area which the person desires to
access before the person steps out onto the roof area.
The device 10 was developed to eliminate the hazard of accessing the
roof by climbing over the eaves using a ladder. The device is installed in the
ridge of
the roof and accessed from the attic access inside trie building. When the top
of the
unit is opened the person may attach their lifeline to the anchor points on
either side
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of the access box. When the person climbs out onto the roof they are protected
from falling.
The device is designed as a Permanent Fall Restraint Anchor, which is
required to have a load capacity of 8.75 kilonewtons (1,967 pound). The device
has
been certified by a professional engineer as a Permanent Fall Restraint with a
2:1
safety factor (17.5 kilonewtons or 3,934 pounds).
The device meets the intent of the Occupational Heath and Safety
Code in Alberta, Canada of October 2003, Section 154(4) & (5) which comes into
force on April 30, 2004. The anchor point is capable of withstanding twice the
maximum arresting force limit of 8 kilonewtons (1,800 pounds force). The
worker
must use equipment as per the legislation including a shock-absorbing lanyard.
Therefore the device meets the requirements as a fall arrest anchor for a wood
framed, sloped roof structure.
Installation of the device 10 is accomplished by the following steps:
1 ) Two trusses are selected where the device 10 will be installed.
This will typically be in the truss space next to the attic access for the
building. A
platform and ladder may be built as shown in the attached drawings if desired.
2) '/ inch thick spruce plywood is then installed on the outside of
the two trusses. 2 pieces of % inch spruce plywood 2 feet by 4 feet and cut
the roof
slope from the center of the top edge. The plywood is installed on the outside
of the
two selected trusses with wood glue and screws. There are fifty 1 %2 inch
course
wood screws provided.
3) A center king post is installed on the trusses consisting of a 2
inch by 4 inch piece of lumber 20 inches in length, while fastening to the
plywood as
well. This is only required on Fink or "W' trusses as the King Post truss
already has
a center post.
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4) A level verfiical line is drawn down the center of the center post
from the peak of the truss. Measuring down from.the peak along the vertical
fine, a
distance is marked of: a) 8" if the slope of the roof is ~41 12; b) 11" if the
slope of the
roof is 6112; or c) 14" if the slope of the roof is 8112. The device may be
used on
slopes greater than 8112, however the horizontal piece of lumber should never
be
set lower than 14 inches from the top of the truss. The ends of the device
containing
the anchor may need to be framed out underneath to the roof deck and a wider
flashing may be required.
5) A level horizontal line is drawn from this mark across the center
post and the top chords of the truss. This is repeated on the opposing truss.
A 2
inch by 4 inch piece of lumber is installed on the insides of both trusses
below this
line. The device sits on these horizontal pieces and is centered on the
vertical line.
6) One tong side of the housing is secured to the respective truss
at one time, starting with the hinge side. 518" holes are drilled into the
truss cords to
match holes in the metal box. There are 5 holes on each side of the unit. It
is only
necessary to use 3 holes on each side. The center hole on each side should
always
be used. On 4/12 slopes the second holes in from each side should be used and
on
6/12 and 8/12 slopes the outside holes should be used. This will allow for the
holes
to be drilled approximately in the center of the truss chords. When installing
the
device on slopes greater than 8/12 it may be necessary to drill an additional
518"
hole in the metal box to ensure the hole is in the center of the truss chord.
7) Once the hinge side is in place, the unit is squared, then holes
are drilled in the opposite truss in a similar manner. All bolts are installed
from the
inside using a washer against the metal and a washer against the plywood on
the
outside along with metal lock nuts. The hinge bolts are then aligned and the
cover is
installed with nylon lock nuts.
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8) Long flashing is provided for the lower horizontal edge and step
flashing is provided for the sides of the unit. Six pieces of flashing seal
strip are also
provided to cover the top edges of the flashing to obtain a weather tight
seal. Some
minor cutting with tin snips may be required during installation. The center
of the
seal strip should be at the top of the flashings. The seal strip is installed
with the
rubber side up against the flashing and affixed with 3/" screws to the sides
of the
unit. Pre-drilled 1I8" holes are preferred for the screws through the seal
strips and
the housing walls. The tips of the screws will protrude into the access area
of the
housing thus it is recommend that the tips be wrapped with a protective
material, for
example duct tape, to prevent cuts and scraps while climbing through the
access
box.
In the preferred embodiment, the device 10 disassembles into 3
pieces, which allows for easier transportation and installation as the
sections can
individually be raised up onto the roof for installation through the hole
formed in the
roof instead of requiring a crane and the like for loading the housing onto
the roof
from above. The 3 pieces include the cover member 42 which can be separated by
a removable hinge pin in the hinge 4.4, and the housing which is formed in two
sections 100. Each section 100 includes one of the short side walls of the
housing
supporting one of the anchors 52 thereon and half of each long side walls so
as to
be generally U-shaped. The sections 100 are assembled at a seam 102 in which
the side walls mate by a lap joint. The sections 100 are bolted together at
each side
of the housing through co-operating apertures at the lap joint. Location of
the seam
to divide the housing transversely to the longitudinal direction is preferred
for
reducing the overall length the sections when disassembled.
The device is supplied with primer coating. The purchaser is required
to finish coat the unit on the outside only. This is typically painted the
color of the
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fascia on the building. The unit is equipped with a hasp and staple, which
will
accommodate a lock. The purchaser should lock the unit to prevent unauthorized
access to the roof.
While one embodiment of the present invention has been described in
the foregoing, it is to be understood that other embodiments are possible
within the
scope of the invention. The invention is to be considered limited solely by
the scope
of the appended Claims.
