Patent Application
20080083183
The invention will now be described by way of example only, with reference to the accompanying drawings, in which:
The steps of constructing the roof system of the present invention are shown in
The first step of re-roofing the existing roof system is to remove a strip 18 of the existing roof and insulation 16 over the open web steel joist 12 as shown in FIG. 2. A plurality of strips 18 will be removed over the roof of the building.
The next step is to fasten a new deck strap 20 over the open web steel joist 12 as shown in
A new roof deck 26 is attached to the upper portions 24 of the deck straps 20 as shown in
Referring to
As will be appreciated by those skilled in the art the re-roofing system shown herein is a solution whereby the contractor is able to leave the existing damaged deck in place and transfer all structural and fire properties to new decking placed above the existing roofing. The new roof is to be located parallel to and directly over the structural roof joists.
The basic proposed means of application is to remove the existing waterproofing and insulating materials or the existing roofing and insulation materials 16 over the areas of damaged existing decking 14, specifically to expose the locations of the structural roof joists 12. The corrosion protected flat roof lift strap 20 would then be mechanically fastened parallel to the structural roof joist without the removal of the existing decking. A flat roof lift strap 20 would be installed at each structural roof joist 12 located in the affected areas. New steel decking 26 of correct structural requirements is then mechanically fastened to the flat roof lift strap, providing a new structural surface maintaining the structural diaphragm, suitable fire protection of new roofing materials 28 and support surface for new low slope or flat roofing materials.
The two possible variations on the application are to either: remove all materials down to the existing decking for the entire affected area as shown in
In order to provide tie-in to existing roofing materials the perimeter of the raised section is suitably canted and sealed to the existing roof.
The strap 20 is varied in dimensions depending on the particular application and the loads required. Specifically the length of the upper portion 24 may vary from the equivalent of one steel deck flute (150 mm) to multiple flutes (1220 mm) and widths of the strap may vary from 50 mm to 200 mm. The height of the flat roof lift strap between the upper portion 24 and the lower portion 22 is varied from 50 mm overall to 250 mm.
The type sizing and spacing of fasteners for both the flat roof lift strap and the new decking is determined by the loading requirements on a per project basis.
As used herein, the terms “comprises” and “comprising” are to construed as being inclusive and opened rather than exclusive. Specifically, when used in this specification including the claims, the terms “comprises” and “comprising” and variations thereof mean that the specified features, steps or components are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.
It will be appreciated that the above description related to the invention by way of example only. Many variations on the invention will be obvious to those skilled in the art and such obvious variations are within the scope of the invention as described herein whether or not expressly described.
