This non-provisional patent application is based on provisional patent application Ser. No. 60/778,204 filed on Mar. 2, 2006. Applicant claims the benefit of the provisional patent application filing date under Title 35, United States Code section 119(e).

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to roofing systems, and, more particularly, to roofing systems that use lightweight insulating concrete with an overly inter-ply sheet and cap membrane on flat or low sloped roof areas.

2. Discussion of the Related Art

Generally, roof systems that use lightweight concrete with or without insulation require a base sheet membrane to be mechanically installed to the lightweight concrete for the purpose of allowing moisture to migrate. Once the base sheet is mechanically attached to the lightweight concrete, additional layers of roofing membrane are attached to the base sheet by either self adhesive, heat weld or cold adhesive. This bonds the membranes together to make up the roof assembly. Despite the widespread use of the mechanically attached base sheet membrane, used in flat and low sloped roof systems, there are significant drawbacks associated with its use. In particular, the increased amount of penetrating fasteners that need to be installed in order to meet the wind uplift requirements actually damage the lightweight the concrete at corners and along the perimeter of the roof. The resultant damage to the lightweight concrete, caused by the closely spaced fasteners, eventually leads to deck failure. Furthermore, when the roof needs to be replaced, requiring removal of the base sheet and fasteners, holes are left in the lightweight concrete. Thereafter, a new base sheet membrane is installed, and new fasteners penetrate additional areas of the existing lightweight concrete deck. Consequently, further damage is caused to the lightweight concrete deck.

It should be noted that the benefit of using lightweight concrete in lieu of insulation is not only to provide a slope for the roof system, but also to provide the owner with an insulating system that will remain intact after re-roofing and continue to provide the owner the slope and insulating value for all future roof systems.

In view of these shortcomings of the traditional mechanically attached base sheet membrane, there exists an urgent need in the roofing industry for an alternative venting system for new and existing lightweight concrete deck structures which overcomes the above described problems. More specifically, there is a need for a venting system that will allow moisture to travel to the perimeter of the roof, where the moisture can exit the roof assembly thru an A.R.B.S. (Alternative Roof Blocking System) of the type disclosed in U.S. Pat. No. 6,237,293 B1. Further, there is a need for venting the top side of a new or existing lightweight concrete deck which will considerably reduce costs for labor and material by eliminating the installation of the base sheet membrane and fasteners that are currently required for attachment to the lightweight concrete deck.

OBJECTS AND ADVANTAGES OF THE INVENTION

A primary object of the present invention is to eliminate the use of the mechanically attached base sheet currently used in flat or low sloped roof systems and to provide the new or existing lightweight concrete with V-grooves on the top surface which replace the function of the base sheet and allow the venting of moisture to travel to the roof perimeter and exit the roof system.

It is a further object of the present invention to provide necessary top side venting of a new or existing lightweight concrete roof deck without compromising the structural integrity of the lightweight system that is presently caused by installation of the base sheet membrane with mechanical fasteners that penetrate the lightweight concrete.

It is still a further object of the present invention to provide venting means in a low-sloped roof system which will release heat and moisture through an arrangement of V-grooves formed in the top side of a lightweight concrete deck.

SUMMARY OF THE INVENTION

The present invention is directed to an improved roof venting system that eliminates the need of a base sheet membrane that is presently used and that is mechanically attached with fasteners to new or existing lightweight concrete. An improved venting system is achieved by installing an arrangement of V-grooves during the installation of new lightweight concrete. The V-grooves are approximately ½ inch to 1 inch deep and are spaced at approximately 3 to 12 inches apart. The V-grooves are installed during the finishing of the top coat using a 4 inch wide by 4 foot long aluminum flat bar having V-groove forming blades welded to bottom side of the tool. The V-groove blades are installed 3 inches on center, 6 inches on center or 12 inches on center, depending on the individual venting needs on new lightweight concrete. On existing lightweight concrete, the V-grooves are cut into the top surface of the lightweight concrete deck with a carbine blade. The V-grooves allow heat and moisture to migrate to the perimeter of the roof and out the vent holes of an A.R.B.S. (Alternative Roof Blocking System) of the type disclosed in U.S. Pat. No. 6,237,293 B1.

BRIEF DESCRIPTIONS OF THE DRAWINGS

For a fuller understanding of the nature of the present invention, reference should be made to the detailed description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a partial perspective view of the lightweight concrete over structural decking having V-grooves installed in the top side of lightweight concrete in order to provide venting for flat or low sloped roof systems without the use of a mechanically attached base sheet; and

FIG. 2 is a partial perspective view showing the roof system of FIG. 1 and illustrating formation of the V-Grooves in the top side of the lightweight concrete by raking with a tool.

Like reference numerals refer to like parts throughout the several views of the drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The improved venting system of the present invention is used in conjunction with a low sloped or flat roof system of the type which uses lightweight insulating concrete. Referring to FIG. 1 and 2, a roof system 10 is applied to a structural roof deck 100 of a building. The system includes a lightweight insulating concrete deck comprising a base layer of lightweight concrete 20, EPS Holey board insulation 22 and a top layer of lightweight concrete 24. The venting system of the present invention is achieved by installing a series of parallel V-grooves 30 on the top side 26 of the top coat 24 of lightweight concrete. The V-grooves 30 are spaced between 3 inches and 12 inches apart on center and are preferably between ½ inch to 1 inch deep. When new lightweight concrete is being installed, the V-grooves are formed during the finishing of the top coat 24 using a rake tool 50, as seen in FIG. 2. In a preferred embodiment, the rake tool 50 has a 4 inch wide by 4 foot long aluminum flat bar 22 having an arrangement of spaced V-groove forming blades 54 on the bottom side. While not shown, the rake tool 50 preferably has an elongate pole with a handle. The pole is fixed to the flat bar and extends upwardly at an angle to facilitate ease of use. The rake 50 is dragged across the top coat 24 to form the V-grooves 30 in the top side 26. On existing lightweight concrete, the V-grooves are cut into the top side 26 with the use of a carbine blade on a rotary saw.

Once the V-grooves 30 are formed in the top side 26, one or more layers of roof membrane 58 are attached to the top side of the lightweight insulating concrete deck. The one or more roof membrane plies 58 are attached to the top side 26 by self adhesion, heat welding or with the use of cold adhesives.

The V-grooves 30 allow heat and moisture to migrate (i.e., within the grooves 30) to the perimeter of the low sloped roof and to release out through vent holes of an A.R.B.S. (Alternative Roof Blocking System) 60, as seen in FIG. 1.

While the present invention has been shown and described in accordance with preferred and practical embodiments thereof, it is recognized that departures from the instant disclosure are contemplated within the spirit and scope of the invention.