UNDER BALLASTED ROOF SUBSTRATE ASSEMBLY

Abstract

A roof substrate assembly includes a structured roof deck, at least one layer of insulation disposed in overlaid arrangement with the roof deck, and at least one layer of weighted coverboard positioned in direct contact with an upper surface of the at least one layer of insulation. The at least one layer of weighted coverboard includes a plurality of panels of coverboard separated by a plurality of abutting joints and a sealant positioned within the plurality of joints to couple the plurality of panels of coverboard.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Application No. 63/487,681, filed Mar. 1, 2023, and U.S. Application No. 63/503,510, filed May 22, 2023, the contents of both are incorporated by reference herein in their entirety.

BACKGROUND

Embodiments of the present disclosure relate to a roofing substrate assembly, and more particularly, to an under ballasted roofing substrate assembly.

Roof structures have been made for millennia ranging from simple lean-to thatched arrangements to more modern buildings having multiple layers of roofing materials, fire barriers, vapor barriers, air retarders, rigid roof insulations, cover boards, slipsheets and waterproofing membranes all designed to work together to keep the elements away from occupants of the building. Roof structures continue to be improved because each of the systems currently available has drawbacks and improvements are therefore desirable.

Common problems of a roof structures typically relative to water-resistance and wind uplift resistance. Wind uplift is a serious concern where an entire roof can be blown off by the low pressure created there above by swiftly moving and tumbling air. Because of these concerns, existing roof systems can be complex and time consuming to build. While roofs of the prior art function sufficiently for their intended purpose, easier to install structures that have the same or greater benefits than those of the prior art would be welcomed.

BRIEF DESCRIPTION

According to an embodiment, a roof substrate assembly includes a structured roof deck, at least one layer of insulation disposed in overlaid arrangement with the roof deck, and at least one layer of weighted coverboard positioned in direct contact with an upper surface of the at least one layer of insulation. The at least one layer of weighted coverboard includes a plurality of panels of coverboard separated by a plurality of abutting joints and a sealant positioned within the plurality of joints to couple the plurality of panels of coverboard.

In addition to one or more of the features described herein, or as an alternative, in further embodiments, the at least one layer of weighted coverboard is an air barrier.

In addition to one or more of the features described herein, or as an alternative, in further embodiments, the at least one layer of weighted coverboard is loosely laid in overlapping arrangement with the at least one layer of insulation.

In addition to one or more of the features described herein, or as an alternative, in further embodiments, the at least one layer of weighted coverboard further comprises a plurality of stacked layers of weighted coverboard.

In addition to one or more of the features described herein, or as an alternative, in further embodiments, the plurality of layers of weighted coverboard are adhered to one another.

In addition to one or more of the features described herein, or as an alternative, in further embodiments, a waterproofing membrane is arranged upwardly adjacent to an upper surface of the at least one layer of weighted coverboard.

In addition to one or more of the features described herein, or as an alternative, in further embodiments, the waterproofing membrane has a plurality of edges and the waterproofing membrane is affixed to the at least one layer of weighted coverboard at only the plurality of abutting edges.

In addition to one or more of the features described herein, or as an alternative, in further embodiments, the waterproofing membrane is affixed to the at least one layer of weighted coverboard at the plurality of joints.

In addition to one or more of the features described herein, or as an alternative, in further embodiments, the waterproofing membrane located between the plurality of joints is not attached to the at least one layer of weighted coverboard.

In addition to one or more of the features described herein, or as an alternative, in further embodiments, at least one opening extends upwardly from above the at least one layer of insulation and at least one equalizer valve mounted within the at least one opening. The at least one equalizer valve is sealed to the waterproofing membrane.

In addition to one or more of the features described herein, or as an alternative, in further embodiments, a nailer is mounted at a perimeter of the roof system, in overlapping arrangement with the waterproofing membrane.

In addition to one or more of the features described herein, or as an alternative, in further embodiments, the nailer is encapsulated by the waterproofing membrane.

In addition to one or more of the features described herein, or as an alternative, in further embodiments, a flashing membrane is separate from the waterproofing membrane, the nailer being encapsulated by the flashing membrane.

According to an embodiment, a roof system includes a structural roof deck, at least one layer of insulation disposed in an overlaying arrangement with the roof deck and a plurality of layers of weighted coverboard positioned upwardly adjacent to an upper surface of the at least one layer of insulation. Adjacent layers of the plurality of layers of weighted coverboard are adhered to one another.

In addition to one or more of the features described herein, or as an alternative, in further embodiments, the plurality of layers of weighted coverboard is positioned in direct contact with an upper surface of the at least one layer of insulation.

In addition to one or more of the features described herein, or as an alternative, in further embodiments a waterproofing membrane is arranged upwardly adjacent to an upper surface of the plurality of layers of weighted coverboard.

According to an embodiment, a method of reroofing an existing roof system includes removing an existing ballast layer and waterproofing membrane to expose a partial roof system, installing at least one layer of weighted coverboard in direct contact with an upper surface of the partial roof system; and sealing a plurality of joints of the at least one layer of weighted coverboard with a sealant to form an air barrier at the at least one layer of weighted coverboard.

In addition to one or more of the features described herein, or as an alternative, in further embodiments installing another waterproofing membrane upwardly adjacent to the at least one layer of weighted coverboard.

In addition to one or more of the features described herein, or as an alternative, in further embodiments only a portion of the another waterproofing membrane is adhered to a surface of the at least one layer of weighted coverboard.

In addition to one or more of the features described herein, or as an alternative, in further embodiments mounting a nailer at a perimeter of the existing roof system, in overlapping arrangement with the waterproofing membrane and encapsulating the nailer within the waterproofing membrane.

BRIEF DESCRIPTION OF THE DRAWINGS

The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:

FIG. 1A is a cross-sectional view of a portion of an under ballasted roof system according to an embodiment;

FIG. 1B is a cross-sectional view of a portion of an under ballasted roof system according to an embodiment;

FIG. 1C is a cross-sectional view of a portion of an under ballasted roof system according to another embodiment;

FIG. 2 is a cross-sectional view of a portion of a roof system including a nailer encapsulated by a flashing membrane and perimeter securement according to an embodiment; and

FIG. 3 is a cross-sectional view of an existing ballasted roof system;

FIG. 4 is a cross-sectional view of the existing ballasted roof system of FIG. 3 with the ballast layer removed and the waterproofing membrane repaired according to an embodiment;

FIG. 5 is a cross-sectional view of the roof system of FIG. 4 including one or more layers of weighted cover board according to an embodiment;

FIG. 6 is a cross-sectional view of the roof system of FIG. 5 including a reinforcing membrane arranged at the perimeter of the roof system according to an embodiment;

FIG. 7 is a cross-sectional view of the roof system of FIG. 6 having the outer end of the reinforcing membrane affixed to an upper surface of the layer of weighted cover board according to an embodiment;

FIG. 8 is a cross-sectional view of the roof system of FIG. 7 including a second waterproofing membrane according to an embodiment;

FIG. 9 is a cross-sectional view of the roof system of FIG. 8 including nailer encapsulated by the second waterproofing membrane according to an embodiment;

FIG. 10 is a cross-sectional view of the roof system of FIG. 8 including an equalizer valve according to an embodiment; and

FIG. 11 is a flow diagram of a method of reroofing an existing building to an under ballasted roof system according to an embodiment.

DETAILED DESCRIPTION

A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.

With reference to FIGS. 1A and 1B, a cross-section of an example of a roof system or roof substrate assembly 20, such as an “under ballasted” roof system is illustrated according to an embodiment. In the illustrated, non-limiting embodiment, the roof system 20 is installed about a building having a building wall 22 that supports a structural roof beam 24, which may include rafters and joists. A roof deck 26, made of metal, concrete or another suitable material overlays the support structure 24. A lower surface of the roof deck 26 may but need not be arranged in direct contact with an upper surface of the support structure 24. Further, the roof deck 26 may be attached to the underlying support structure 24 via any suitable means. Although fasteners 28 are illustrated in the embodiments as being used to affix the roof deck 26 to the support structure 24, it should be appreciated that other connection means, such as adhesive for example, may be used in addition to or as an alternative to the fasteners 28.

In the illustrated, non-limiting embodiment, the roof deck 26 is formed from a plurality of panels of metal corrugated roof decking. Because corrugated metal roof decking or any other modular decking material has a certain size and shape, in some embodiments, the roof deck 26 will include one or more joints or sections where adjacent panels or pieces of the roof decking overlap or abut. In FIGS. 1A and 1B, panels of the roof decking used to form the roof deck 26 may include a plurality of upper flutes and a plurality of lower flutes. An overlap section formed between adjacent panels of metal decking material may include one or more overlapping flutes.

At least one layer of insulation 30 may be disposed vertically above the roof deck 26. The insulation may be a lightweight, rigid, closed cell insulation, such as formed from polyisocyanurate or expanded or extruded polystyrene or another insulating material common to the roofing industry. In the illustrated, non-limiting embodiment, the at least one layer of insulation 30 is located upwardly adjacent, and in some embodiments in direct contact with a surface of the roof deck 26. The insulation 30 may be “loose laid” and therefore is not mechanically or chemically fastened or adhered directly to an adjacent component of the roof system 20, such as the roof deck 26 for example. However, embodiments where the insulation 30 is installed using a fastener and/or an adhesive for example, are also within the scope of the disclosure. In embodiments where a layer of insulation is installed using one or more fasteners, the fasteners may couple the insulation to the roof deck, and in some embodiments to the building support structure.

In the illustrated, non-limiting embodiment, the roof system 20 includes a plurality of layers of insulation, such as three layers of insulation 30a, 30b, 30c for example. Although three layers of insulation are illustrated in the FIG., embodiments including a single layer of insulation, two layers of insulation, or four or more layers of insulation are within the scope of the invention. The plurality of layers of insulation may be arranged directly adjacent to one another, or alternatively, may be separated from one another by another component of the roof system. In embodiments having a plurality of layers of insulation, adjacent layers of insulation may be locally attached to one another, such as with an adhesive, liquid nail, or spray foam for example. However, embodiments where adjacent layers or insulation are not locally attached to one another are also contemplated herein.

Further, in embodiments including a plurality of layers of insulation, each of the layers of insulation may be the same material, or alternatively, may be different materials. For example, in the illustrated, non-limiting embodiment, a first layer of insulation 30a located directly adjacent to the roof deck 26 and a second layer of insulation 30b disposed upwardly adjacent to and in direct contact with the first layer of insulation 30a may be a first material or construction, such as an expanded polystyrene having closed cells that are filled with air. A third layer of insulation 30c is disposed upwardly adjacent to and in direct contact with the second layer of insulation 30b. However, the third layer of insulation 30c may be a second type of material or may have a different type of construction that the first and second layers of insulation 30a, 30b. In addition, it should be appreciated that one or more other components of the roof system 20 may be disposed between adjacent layers of the plurality of layers of insulation.

In the illustrated, non-limiting embodiment of FIG. 1A, a waterproofing membrane 32 is positioned in contact with an upper surface of the uppermost layer of insulation, such as layer 30c for example. The waterproofing membrane 32 may be made of ethylene propylene diene monomer (EPDM), chlorosulfonated polyethylene (CSPE), polyvinyl chloride (PVC), thermoplastic polyolephin (TPO), SBS modified Bitumen, or other similar roof waterproofing single ply membranes. The waterproofing membrane 32 may form an air barrier preventing not only air from permeating through the insulation into the building, but also preventing air within the building from escaping through the insulation. However, in other embodiments, such as shown in FIG. 1B, the roof system 20 does not include the waterproofing membrane 32.

In embodiments including the waterproofing membrane, one or more layers of a weighted coverboard 34 are positioned over, and in some embodiments directly adjacent to the upper surface of the waterproofing membrane 32. However, in other embodiments, such as when a waterproofing membrane 32 is not present, at least one layer of weighted coverboard is positioned in overlapping arrangement with and in some embodiments in directly contact with an upper surface of the uppermost layer of insulation. Each layer of weighted coverboard 34 has a substantially uniform weight across the entire roof system 20, regardless of its position relative to a perimeter thereof. The weight of the coverboard 34 is generally between about 1 pound per square foot and about 10 pounds per square foot, such as between about 1.5 and about 3 pounds per square foot, such as about 2.5 pounds per square foot for example. The weight of the coverboard 34 may vary in part based on the thickness of the coverboard 34 and is selected based on the intended application of the coverboard. The weighted coverboard 34 may additionally have properties such that it holds its shape, even while being pulled non-uniformly by attachments to the roof and building structures for example. Because of this tendency to retain its shape, the coverboard evenly distributes loads applied thereto to minimize localized stress levels.

The coverboard 34 generally includes one or more of plywood, oriented strand board, gypsum, rigid fiber board, cement board or other relatively heavy solid board material for example. In an embodiment, the weighted coverboard 34 is Kelly Green Board manufactured by Kelly Green Products. In such embodiments, a core of the coverboard 34 is formed from a moisture and mold resistant composite material. In an embodiment, the composite material is formed entirely from recycled materials, such as beverage cartons, ice cream cartons, and cups for example. Because Kelly Green Board is formed without the use of formaldehyde glues, or other hazardous chemicals, the coverboard 34 is free from volatile organic compounds. In an embodiment, the coverboard 34 may have fire-resistant properties such that the coverboard may function as a fire barrier, and in some embodiments may be self-extinguishing. Alternatively, or in addition, the coverboard 34 may be water-resistant or waterproof.

A layer of weighted coverboard 34 typically comprises a plurality of substantially identical panels laid adjacent to one another such that the abutting edges of the panels form a plurality of joints. In embodiments including a plurality of layers of weighted coverboard 34 stacked vertically on top of one another, at least some of the joints formed in the adjacent layers may be offset or horizontally staggered relative to one another. However, embodiments where a layer of weighted coverboard 34 includes a single panel of coverboard are also contemplated herein. In the illustrated, non-limiting embodiment, the one or more panels of coverboard 34 are “loosely laid” over the waterproofing membrane 32 or the uppermost layer of insulation 30c. However, embodiments where the coverboard 34 is adhered to or mechanically fastened to another of the roof system 20 are also within the scope of the disclosure.

A sealant 36 may be positioned in and/or adjacent to the joints formed between the abutting edges of adjacent panels of a layer of the weighted coverboard 34. The sealant 36 may be any suitable type of sealant, including a silicone roof coating or adhesive strips example. In an embodiment, the sealant 36 blocks the flow of air through the joints between adjacent panels of coverboard 34. Because the coverboard 34 is formed from an impervious material through which air cannot flow, together the layer of coverboard 34 and the sealant 36 positioned in the joints cooperate to form an air barrier of the roofing system 20. In some embodiments, a layer of reinforcing mesh or mesh material (not shown) is arranged at the joints and is sealed thereto by the sealant 36. By filling the joints formed between adjacent panels of weighted coverboard 34 with a sealant 36, the plurality of panels are joined to form a monolithic ballast layer. Such a layer will share loads acting thereon, such as by distributing the wind uplift turbulent pressures occurring at a perimeter edge of a building to the interior of the roof. In embodiments including a plurality of layers of coverboard 34, adjacent layers may be adhered to one another via an adhesive or the sealant. In an embodiment, a portion of the sealant 36 provided to a joint within an upper layer of coverboard 34 leaks onto a surface of a lower layer of coverboard. Accordingly, adjacent layers of coverboard 34 may be adhered to one another at the joints formed in at least one of the layers. However, application of a different sealant may also be used to couple stacked layers of coverboard 34 together.

A layer of reinforced membrane 38 may be arranged at the perimeter or edge of the roof system 20. As shown, a first interior edge 38a of the reinforced membrane 38 may be affixed to an upper surface of the at least one layer of weighted coverboard 34, such as via an adhesive or tape for example. In the illustrated, non-limiting embodiment, the first interior edge 38a of the reinforced membrane is affixed to a panel of weighted coverboard 34 that is spaced from the edge of the roof system 20. Accordingly, the reinforced membrane 38 may be positioned underneath an outermost panel of the at least one layer of coverboard 34 located adjacent to the perimeter of the roof system 20, the outermost panel being identified herein as 34E. The first interior edge 38a is configured to extend through the gap or joint between the outermost panel 34E and an adjacent panel of coverboard, identified herein as 34I, to adhere to an upper surface of the uppermost adjacent panel 34I. In such embodiments, one or more fasteners 40 may extend through the outermost panel 34E of the at least one layer of weighted coverboard 34 to affix the outermost panel to at least one of the building 22, the support structure 24, and the roof deck 26.

A second opposite edge or exterior edge 38b of the reinforced membrane 38 may be configured to wrap about the exterior facing surface of the outermost panel of the at least one layer of coverboard 34. As shown, the second, exterior edge 38b of the reinforced membrane may be adhered to an upper surface of the upper, outermost panel 34E, to an upper surface of the adjacent interior panel 34I, or to an upper surface of the reinforced membrane 38 at the upper surface of the adjacent interior panel 34I. Accordingly, at least a portion of the outermost panel(s) 34E, including the exterior facing surface may be encapsulate by the reinforced membrane 38. Alternatively, or in addition, the second exterior edge 38b of the reinforced membrane may be disposed fastened to the layer of coverboard 34 by the one or more fasteners 40, such as used to mount the coverboard 34 to the building 22, the roof deck 26, or the support structure 24.

In an embodiment, a second waterproofing membrane 42 is positioned in overlaying arrangement with the upper surface of the uppermost layer of weighted coverboard 34. Further, the second waterproofing membrane 42 may overlay the interior and exterior edges 38a, 38b of the reinforced membrane arranged at the upper surface of the weighted coverboard 34. As shown, the second waterproofing membrane 42 may be coupled to the upper surface of the weighted coverboard 34 and/or the reinforced membrane 38 via any suitable mechanism including a bonding adhesive, heat weld, hot tar, or tape for example. However, it should be appreciated that embodiments of the roofing system 20 that do not include the second waterproofing membrane 42 are also within the scope of the disclosure.

In the illustrated, non-limiting embodiment, only a small portion of a surface of second waterproofing membrane 42, such as at the edges thereof for example, is adhered to the adjacent surface of the coverboard 34 and/or reinforced membrane 38. As a result, the second waterproofing membrane 42 between the adhered locations, which is the substantial majority of the second waterproofing membrane 42, may be considered “loose.” However, embodiments where the second waterproofing membrane 42 is adhered over its entire surface to the reinforced membrane 38 and/or the coverboard 34 and also embodiments where no portion of the second waterproofing membrane 42 is adhered to the reinforced membrane 38 and/or to the coverboard 34 are also within the scope of the disclosure. An outer edge 42a of the second waterproofing membrane 42 may extend beyond the perimeter edge of the roof and along a portion of a side of the building 22. In an embodiment, the outer edge 42a of the second waterproofing membrane 42 forms a perimeter membrane that flashes to a gutter (not shown) attached to the building 22.

In an embodiment, a nailer 50 is arranged at the perimeter of the roof system 20 in overlapping arrangement with a surface of the second waterproofing membrane 42. The nailer 50 may be mechanically coupled to the building 22 via one or more fasteners 52, such as screws or nails for example. In the illustrated, non-limiting embodiment, the nailer 50 is positioned directly upwardly adjacent the surface of the second waterproofing membrane 42. In such embodiments, the second waterproofing membrane 42 may wrap about the periphery of the nailer 50 to substantially seal or encapsulate the nailer 50 within the second waterproofing membrane 42. When the nailer 50 is encapsulated by the second waterproofing membrane 42, the outer edge 42a of the second waterproofing membrane 42 is disposed directly adjacent to and is bonded to a surface of a central portion of the second waterproofing membrane 42, such as via an adhesive, heat weld, or tape for example. The second waterproofing membrane 42 may also be bonded to one or more surfaces of the nailer 50.

In other embodiments including a nailer 50, such as shown in FIG. 2 for example, a flashing membrane 54 separate from the second waterproofing membrane 42, may be used to encapsulate the nailer 50. In such embodiments, the flashing membrane 54 is disposed upwardly adjacent to the upper surface of the second waterproofing membrane 42, such as near the perimeter of the roof system 20 for example, and may be adhered thereto, such as with a tape or other adhesive. As shown, the end 54a of the flashing membrane 54 is adhered to a corresponding surface of the flashing membrane 54 and, in some embodiments, to a surface of the second waterproofing membrane 42.

Venting may be needed in order to prevent the roof system 20 from becoming damaged by zones of low pressure above the roof system 20. Accordingly, in an embodiment, at least one equalizer valve 60 may be mounted at a location of the roof system 20 identified as a “wind uplift vortex intensity zone.” Examples of suitable equalizer valves 60 includes those that are described in U.S. Pat. Nos. 4,223,486 and 4,557,081, both of which are incorporated herein by reference. As shown, an equalizer valve 60 may be aligned with an opening 62 formed in the roof system 20. The at least one opening 62 may extend through each of the layers of the roof system 20 positioned above the insulation 30 and/or the waterproofing membrane 32. These layers may include the second waterproofing membrane 42 and the at least one layer of weighted coverboard 34. In the illustrated, non-limiting embodiment, the interface between the equalizer valve 60 and the adjacent second waterproofing membrane 42 is sealed, such as with an adhesive or sealant for example.

In embodiments including the waterproofing membrane 32 positioned between the insulation 30 and the one or more layers of coverboard 34, the waterproofing membrane 32 provides an air barrier within the interior of the roof system 20. However, by sealing the plurality of joints 36 of the layer of weighted coverboard 34, the layer of coverboard may form an air barrier. The resulting monolithic ballast layer is protected from the internal building pressure and is resistant to wind uplift forces acting on the roof system 20.

With reference to FIG. 11, a method 100 for replacing an existing ballasted roof system is illustrated. As shown, in block 102 and FIG. 3, a ballast layer 70 is removed from the top surface of the existing roof system. In an embodiment, the ballast layer 70 is in the form of pavers or looser stones. Upon removal of the ballast layer 70, the original waterproofing membrane 32 is exposed. In an embodiment, the original waterproofing membrane 32 is also removed from the roof system, as shown in block 103. However, in another embodiment, as shown in block 104, any tears, cuts, or open seams in the now exposed original waterproofing membrane 32 are repaired. As best shown in FIG. 4, such repairs may be formed using cured cover tape, and in some embodiments, by splicing new pieces of waterproofing membrane to the old membrane 32, such as via a heat weld, seam tape, or other suitable adhesion process. Once repair of the membrane 32 is completed such that the waterproofing membrane 32 has a continuous, uninterrupted surface over the roof system 20.

In block 106, at least one layer of weighted coverboard 34 is installed upwardly adjacent to and in direct contact with the waterproofing membrane 32, or in some embodiments with the exposed upper surface of a layer of insulation. As previously described, the panels forming each layer of weighed coverboard 34 may be loosely laid on top of the waterproofing membrane 32 or layer of insulation. It should be appreciated that the panels of coverboard 34 arranged directly adjacent to a perimeter or edge of the roof system 20 will not be installed at this time. With reference to FIG. 5, during installation, the joints formed between adjacent panels are also sealed with a sealant 36, and in some embodiments a mesh or fabric material, to form an air barrier.

In block 108, a reinforced membrane 38 is installed at the perimeter of the roof system. 20 As previously described, and as best shown in FIG. 6, a first interior edge 38a of the reinforced membrane 38 is affixed to an upper surface of a panel of coverboard 34, such as an interior panel 34I, installed about roof system 20. The adjacent portion of the reinforced membrane 38 is disposed in overlapping arrangement with, and in some embodiments is directly adhered to, the exposed surface of the waterproofing membrane 32 or the exposed surface of the insulation 30c at the perimeter. In block 110, and as shown in FIG. 7, the outermost panels 34E of the one or more layers of weighted coverboard are then installed between the interior panels 34I and the edge of the roof system, over the reinforced membrane 38. Further, a second end of the reinforcing membrane is then wrapped about an exterior edge of the outermost panels 34E of the one or more layers of weighted coverboard and is connected or affixed to the upper surface of the top, outermost panel 34E.

In block 112, and as shown in FIG. 8, a second waterproofing membrane 42 is then installed over the coverboard 34 and the portion of the reinforced membrane 38 above the coverboard 34. In an embodiment, as shown in block 114, a nailer 50 is optionally installed in overlapping arrangement with the second waterproofing membrane 42. The nailer 50 may be encapsulated by a free end of the second waterproofing membrane 42, or by a separate flashing membrane 54 as previously described. Instead of installing the encapsulated nailer 50, or alternatively, after installing the encapsulated nailer, one or more openings 62 are formed in the roof system in fluid communication with the membrane 32 and a corresponding equalizer valve 60 is installed in each opening 62.

Existing systems that use one or more layers of weighted coverboard as a ballast layer in a roofing system having an air permeable deck typically do not seal the panels within a layer together or stacked panels to one another. As a result, such coverboard is typically positioned between an upper and lower waterproofing membrane, and the membranes and coverboard in combination form an air barrier. This is distinguishable from the roofing system 20 disclosed herein where a sealed layer of coverboard 34 may be positioned directly adjacent to a layer of insulation and can form both air barrier and a moisture barrier.

The term “about” is intended to include the degree of error associated with measurement of the particular quantity based upon the equipment available at the time of filing the application.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, element components, and/or groups thereof.

While the present disclosure has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the present disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present disclosure without departing from the essential scope thereof. Therefore, it is intended that the present disclosure not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this present disclosure, but that the present disclosure will include all embodiments falling within the scope of the claims.

Claims

1. A roof substrate assembly comprising:

a structure roof deck;

at least one layer of insulation disposed in overlaid arrangement with the roof deck; and

at least one layer of weighted coverboard positioned in direct contact with an upper surface of the at least one layer of insulation, the at least one layer of weighted coverboard further comprises:

a plurality of panels of coverboard separated by a plurality of abutting joints; and

a sealant positioned within the plurality of joints to couple the plurality of panels of coverboard.

2. The roof system of claim 1, wherein the at least one layer of weighted coverboard is an air barrier.

3. The roof system of claim 1, wherein the at least one layer of weighted coverboard is loosely laid in overlapping arrangement with the at least one layer of insulation.

4. The roof system of claim 1, wherein the at least one layer of weighted coverboard further comprises a plurality of stacked layers of weighted coverboard.

5. The roof system of claim 4, wherein the plurality of layers of weighted coverboard are adhered to one another.

6. The roof system of claim 1, further comprising a waterproofing membrane arranged upwardly adjacent to an upper surface of the at least one layer of weighted coverboard.

7. The roof system of claim 6, wherein the waterproofing membrane has a plurality of edges and the waterproofing membrane is affixed to the at least one layer of weighted coverboard at only the plurality of abutting edges.

8. The roof system of claim 6, wherein the waterproofing membrane is affixed to the at least one layer of weighted coverboard at the plurality of joints.

9. The roof system of claim 8, wherein the waterproofing membrane located between the plurality of joints is not attached to the at least one layer of weighted coverboard.

10. The roof system of claim 6, further comprising:

at least one opening extending upwardly from above the at least one layer of insulation; and

at least one equalizer valve mounted within the at least one opening, the at least one equalizer valve being sealed to the waterproofing membrane.

11. The roof system of claim 6, further comprising a nailer mounted at a perimeter of the roof system, in overlapping arrangement with the waterproofing membrane.

12. The roof system of claim 11, wherein the nailer is encapsulated by the waterproofing membrane.

13. The roof system of claim 12, further comprising a flashing membrane separate from the waterproofing membrane, the nailer being encapsulated by the flashing membrane.

14. A roof system comprising:

a structural roof deck;

at least one layer of insulation disposed in an overlaying arrangement with the roof deck;

a plurality of layers of weighted coverboard positioned upwardly adjacent to an upper surface of the at least one layer of insulation, wherein adjacent layers of the plurality of layers of weighted coverboard are adhered to one another.

15. The roof system of claim 14, wherein the plurality of layers of weighted coverboard is positioned in direct contact with an upper surface of the at least one layer of insulation.

16. The roof system of claim 14, further comprising a waterproofing membrane arranged upwardly adjacent to an upper surface of the plurality of layers of weighted coverboard.

17. A method of reroofing an existing roof system comprising:

removing an existing ballast layer and waterproofing membrane to expose a partial roof system;

installing at least one layer of weighted coverboard in direct contact with an upper surface of the partial roof system; and

sealing a plurality of joints of the at least one layer of weighted coverboard with a sealant to form an air barrier at the at least one layer of weighted coverboard.

18. The method of claim 17, further comprising installing another waterproofing membrane upwardly adjacent to the at least one layer of weighted coverboard.

19. The method of claim 18, wherein only a portion of the another waterproofing membrane is adhered to a surface of the at least one layer of weighted coverboard.

20. The method of claim 18, further comprising:

mounting a nailer at a perimeter of the existing roof system, in overlapping arrangement with the waterproofing membrane; and

encapsulating the nailer within the waterproofing membrane.