US20010052207A1

US20010052207A1 - Roofing ventilation systems and methods

Info

Publication number: US20010052207A1
Application number: US09/801,161
Authority: US
Inventors: Robert Davis
Original assignee: BOB DAVIS ROOFING
Current assignee: BOB DAVIS ROOFING
Priority date: 2000-03-06
Filing date: 2001-03-06
Publication date: 2001-12-20

Abstract

A ventilation structure is provided for use with a roof comprising a longitudinal or transverse opening defined by a roof deck. The ventilation structure comprises a base portion defining a central ventilation channel and a venting portion coupled to the base portion. The venting portion has a proximate end and first and second distal ends, wherein the venting portion defines first and second passages, the first passage extending from the proximate end to the first distal end and the second passage extending from the proximate end to the second distal end. The venting portion defines first and second ventilation panels at the first and second distal ends, respectively, whereby air flows from the central ventilation channel through the first and second ventilation panels.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit of U.S. Provisional Application No. 60/186,986, entitled “Roofing Ventilation Systems and Methods,” filed Mar. 6, 2000.[0001]

FIELD OF THE INVENTION

The present invention is related to the general field of attic and roof ventilation systems. It is particularly related to passive ventilation systems that provide ventilation to attic or roof closures.

BACKGROUND OF THE INVENTION

A continuing problem in roof construction techniques is how to ventilate the crawlspace (commonly in the form of an attic) properly to prevent the buildup of excessive heat. Improperly ventilated roofing decreases the life span of the roof itself because the built-up heat in effect “cooks” the roofing material. Sunlight heats the exposed portion of the roof which in turn heats the underside of the roof and the crawlspace. If the heat in the area underneath the roof is not allowed to escape efficiently, the temperature on the underside of the roof can exceed 300 degrees Fahrenheit. At this temperature, especially over an extended period of time, the roofing material can sometimes crystallize or deform resulting in leaks or other structural deficiencies.

Numerous attempts have been made to alleviate this problem by installing vents at various points in the roofing structure. One common technique is to include vents on the underside of the soffet of the roof (i.e. on the underside of the eves). While this does allow some of the heat to escape, the ventilation provided remains poor. Because the vents are located on the underside of the eves, the heat must build up to extremely high levels before it is forced downwardly out of the vents due to the fact that heat naturally rises. This also causes a non-uniform heat distribution within the attic or roof structure. Because the heat rises the temperature closest to the roof will consistently remain at temperatures higher than that of the areas further away from the roof and near the eaves. Also, in sloped roof structures, the heat will concentrate at the apex creating higher temperatures at the apex, which steadily decrease along the roofline towards the eaves. Thus, the air allowed to escape at the eaves is not even the hottest air.

In flat roofs, similar attempts have been made to increase ventilation. In one common technique, a hole is cut in various parts of the roof and then covered with box-like ventilation ducts. These ducts are spaced at various points along the roof and are sealed using tar or rubber compounds. These ducts, however, create additional problems. First, because the ducts are spaced at various points in the roof, the areas closet the vents are better ventilated than the remainder of the roof. Areas distant from the vents are poorly ventilated resulting in numerous “dead zones” where hot air may build up. These vents may also be prone to leaking. As the rubber or tar compounds age and dry out, cracks develop which allow water to seep in around the points where the vents are connected to the roof.

A similar configuration uses “twirly birds” or mushroom-shaped ventilation ducts that rotate when the wind blows to help draw heat from beneath the roof. Although these provide the advantage of creating a limited degree of suction to draw out the heated air, they are typically smaller than the box vents and thus result in non-ventilated spaces or dead-zones. In addition, they also suffer from the same leakage problems found in the box-type vent structures.

Other systems, such as that disclosed in U.S. Pat. No. 5,826,383, have attempted to resolve some of the heating and leakage problems by employing complicated venting systems adapted to particular sloped metal roofs. This reference using a ridge closure vent that is adapted for sloped metal roofs having ridge slots formed thereon. The ridge closure vents solves some of the problems encountered in the prior art by enabling some of the air trapped in the roof closure to escape. The ridge closure vent disclosed, however, is overly complex in that it requires the construction of two separate closure members separated by a mesh mat. Each closure member must also be formed to so that it profile matches the contour of the roof panels. This complicated construction make installation more difficult and increases both the costs of labor and materials and the chances that the ventilation system will be incorrectly installed. Furthermore, since the ridge closure vent is formed over the underlying roof panels, only the slope of the roof prevents water from seeping underneath. However, in heavy winds or storms, water may seep underneath the ridge closure vent. This construction also makes this structure impractical for use on flat or slightly sloped roofs.

SUMMARY OF THE INVENTION

A ventilation structure is provided for use with a roof comprising a longitudinal or transverse opening defined by a roof deck. The ventilation structure comprises a base portion defining a central ventilation channel and a venting portion coupled to the base portion. The venting portion has a proximate end and first and second distal ends, wherein the venting portion defines first and second passages, the first passage extending from the proximate end to the first distal end and the second passage extending from the proximate end to the second distal end. The venting portion defines first and second ventilation panels at the first and second distal ends, respectively, whereby air flows from the central ventilation channel through the first and second ventilation panels. The base portion of the ventilation structure may also comprise first and second mounting flanges for mounting the ventilation structure to the roof deck and substantially parallel side walls, wherein the first and second mounting flanges extend substantially laterally from the first and second side walls, respectively.

The ventilation structure may optionally comprise a cant secured to the base portion that extends from one of the first and second flanges to the corresponding first or second side wall. A layer of insulating material may also be formed over the cant to provide a curved incline sloping away from the base portion. In one embodiment, the first and second ventilation panels comprise ventilation openings and may also include a screening material formed over the ventilation opening. The ventilation opening may comprise a perforation formed substantially laterally through the ventilation panel.

In another embodiment of the present invention, a ventilation structure is provided for use on a roof comprising a longitudinal or transverse opening defined by a roof deck containing laterally displaced vertical extensions. In this embodiment, the ventilation structure comprises first and second rain closures attached to the roof deck, each rain closure comprising a face and upper and lower flanges extending from opposite ends of the face, wherein each rain closure extends between the laterally displaced vertical extensions of the roof deck, and wherein the lower flange of each rain closure is attached to the roof deck. The ventilation structure also comprises first and second venting panels, each venting panel comprising a second face disposed between upper and lower extensions, wherein the second face of each venting panel contains a ventilation opening that allows air to pass therethrough, and wherein the lower extensions of the first and second venting panels are attached to the corresponding upper flanges of the first and second rain closures. A ventilation cap is attached to the upper extensions of the first and second venting panels, wherein the ventilation cap extends over the upper extensions of the venting panels. The ventilation structure may also be formed such that at least one of the first and second venting panels is attached to the rain closure such that the face of the venting panel is offset from the face of the rain closure. Alternatively, the ventilation structure may include a venting panel and ventilation cap that comprise a unitary structure.

In yet another embodiment, a ventilation structure is provided comprising first and second venting panels, each venting panel comprising a face disposed between upper and lower extensions, wherein the face of each venting panel contains a ventilation opening that allows air to pass therethrough, and wherein the lower extensions of the first and second venting panels are attached to the roofing deck. A ventilation cap attached to the upper extensions of the first and second venting panels, wherein the ventilation cap extends over the upper extensions of the venting panels. In this embodiment, a roofing material may formed over the lower extension of the first and second venting panels. The ventilation structure may also be formed such that the venting panels and ventilation cap comprise a unitary structure.

In addition, the above ventilation structures may also comprise a plurality of venting panels and/or a venting panel that contains a plurality of ventilation openings. A screening material may also be formed over one or more of the ventilation openings.

This invention also includes a method of ventilating an attic using the ventilation structure described above.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows a perspective view of one embodiment of the present invention in an exploded view, wherein only a portion of the components are illustrated for clarity of the illustration; [0014]
FIG. 1B shows a front elevational view taken along [0015] lines 1B′-1B′ of the embodiment of FIG. 1A.
FIG. 2A shows a side cross-sectional view of the same embodiment shown in FIG. 1A, taken along lines [0016] 2A′-2A′.
FIG. 2B shows a cross-sectional end view of an installed ventilation system in accordance with the embodiment of FIGS. 1A, 1B, [0017] 2A, and 2B.
FIG. 2C shows a cross-sectional end view of an installed ventilation system according to another embodiment of the present invention [0018]
FIG. 3 shows a perspective view of one embodiment of the present invention, wherein only a portion of the components are illustrated for clarity of the illustration. [0019]
FIG. 4 shows a cross-sectional end view of an installed ventilation system according to another embodiment of the present invention. [0020]
FIG. 5 shows a cross-sectional end view of an installed ventilation system according to another embodiment of the present invention. [0021]
FIG. 6 shows a cross-sectional end view of an installed ventilation system according to another embodiment of the present invention.[0022]

DESCRIPTION OF THE INVENTION

The present invention solves many of the problems of the prior art ventilation systems by providing a uniformly distributed ventilation system that is structurally secure and easy to fabricate and install. FIG. 1A shows a perspective view of one embodiment of the present invention in an exploded view, wherein only a portion of the components are illustrated for clarity of the illustration, and FIG. 1B shows a front elevational view taken along [0023] lines 1B′-1B′ of the embodiment of FIG. 1A. FIG. 2A shows a side cross-sectional view of the same embodiment shown in FIG. 1A, taken along lines 2A′-2A′, and FIG. 2B shows a cross-sectional end view of an installed ventilation system in accordance with the embodiment of FIGS. 1A, 1B, 2A, and 2B.
FIGS. 1A, 1B, [0024] 2A, and 2B generally show one embodiment of the present invention that may be used with a metal stadine seam roof comprising an opening defined by a roof deck containing laterally displaced vertical extensions (although this embodiment may be used with other roof structures as well. In this embodiment, the ventilation structure comprises a ventilation cap 10 that is securely attached to venting panels 12 (of which FIG. 1A only shows one for purposes of clarity of the illustration; an opposing venting panel 12 would be provided on the opposite side of the opening 8 in the apex of the roof for supporting the cap 10 in an actual installation, as illustrated in FIG. 2B). The venting panels 12 comprise a face disposed between upper and lower extensions. The venting panels 12 are attached to rain closures 14 which comprise a face and upper and lower flanges extending from opposite ends of the face. In a preferred embodiment, the lower extension of the venting panel is attached to the upper flange of the rain closure 14. It will be appreciated that the terms “flange” and “extension” are used interchangeably herein and are not intended to connote a different structure. Both the flanges and extensions herein may be formed from a single piece of construction material such as metal. In addition, both flanges and extensions may extends from their respective faces in more than one direction.
The [0025] rain closures 14 are, in turn attached to the roof deck (also called the roof substrate). In one embodiment, the rain closures 14 are fitted directly into a roof pan 16 defined by laterally displaced vertical extensions (which preferably extend from the opening in the roof towards the outer edge of the roof) using techniques well know in the art. In a preferred embodiment, the lower flange of the rain closure is attached to the roofing pan (or the roof deck) using any of several well-known fastening means such as rivets, nails, screws, etc. Advantageously, the rain closure prevents moisture and water from seeping into the opening 8 in the roof and provides a base upon which to attach the venting panels such that the ventilation openings are further displaced from the roofing pan where water may collect. In another preferred embodiment, the face of the venting panels 12 is offset from the face of the rain closures 14, such that the venting panels are closer to the outer edge of the roof and the face of the rain closures are closer to the roof opening. This embodiment provides even greater insulation from rain and debris because any such matter must travel the additional distance provided by the offset. The venting panels 12 are typically configured in a z-type configuration with the upper and lower extensions defining opposing ends of the “z”, although other configurations (such as configurations formed similar to an I-shape) could be used.
The [0026] ventilation cap 10, venting panels 12, rain closures 14, and roof pan 16 may be formed of any durable material but are preferably formed using aluminum, galvanized steel, copper, or a similar metal. However, one or more of these components may be formed of rigid plastic, wood, or other materials commonly used in construction. One advantage of the present invention is that it may be easily fabricated using common materials while still providing improved ventilation and preventing leakage and the entry of debris in the roofing closure, attic, or similar structure.
The venting [0027] panels 12 preferably comprise ventilation openings 18 that allow the air to be conducted through the openings to the outside. The ventilation openings are shown in FIG. 1B as circular perforations, but any of several ventilation openings could be employed such as square or rectangular shaped perforations, but there should be sufficient openings to allow air to escape at a desired flow rate through the panels 12. Alternatively, the venting panel may include numerous spaced slots along its length that may be covered with a screening material (such as wire or plastic mesh), if desired, to prevent objects from entering through the holes. It will be appreciated that the screening material may also be employed with other types of openings, including perforations.
The [0028] ventilation cap 10 is attached to the venting panels 12 using any of several well-known fastening means such as rivets or screws. Preferably, the ventilation cap is attached to the upper extensions of opposing venting panels such that the ventilation cap extends over the upper extensions. Alternatively, a modified ventilation cap 10′ can be fastened directly to the rain closure 14, as illustrated in FIG. 2C. In this embodiment, the openings 18 are included as part of the ventilation cap 10′ in a unitary structure as shown in FIG. 2C. Advantageously, this embodiment enables the ventilation cap and openings to be formed from a single sheet of material (such as metal) thereby reducing fabrication and assembly costs. The fastening means, regardless of the design of the cap, should be chosen to account for the wind lift factor of the ventilation cap 10 to prevent the cap from dislodging due to wind gusts. Advantageously, the invention can be installed along the entire length of a roof to prevent the formation of dead spots. This also ensures more uniform ventilation throughout the length of the roof.
Advantageously, although the invention is shown in FIGS. [0029] 1-2 on a sloped roof, it is equally well suited for use on flat roof configurations because the attaching means ensures that moisture is not allowed to enter through the roof opening. In flat roof configurations, the present invention provides for a opening 20 in the roof 22 that can serve advantageously as an expansion joint throughout the length of a roof structure. In this embodiment, the ventilation cap 10 and venting panel 14 are installed in sections 24A, 24B, and 24C with each section overlapping the other as shown in FIG. 3. The sections may then be connected using a standard z-type connection or any of several other connection techniques well know in the art. These overlapping sections absorb (i.e., adapt to) the natural expansion and contraction of the roof 22 according to temperature variations. A particular design in accordance with the present invention for use with flat roofs is described in detail below with reference to FIG. 6.
In another embodiment of the present invention, the invention may be installed as part of the overall roof design. Thus, it may be built directly into the roof substrate regardless of whether the roof is metal or shingled, flat or sloped. In metal roofs, the venting panel and ventilation cap are installed directly to the rain closure as described above. The rain closure and the roofing pan are configured so as to leave an opening at the apex of the roof (in the case of sloped roofs) or at spaced intervals (in the case of flat roofs). In a preferred embodiment, the opening spans the length of the roof to provide more uniform ventilation. [0030]
In shingled roofs, as illustrated in FIG. 4, the base of the venting [0031] panels 12′ may be secured directly to the roof substrate (also known as the roof deck) using any of several well-known fastening means such as nails, screws or rivets. The roof is then built over the base of the venting panel 12′ by laying the tar and shingles over the venting panel and securing them directly to the venting panel. In this embodiment, the lower extension of the venting panels 12′ preferably extends away from the roof opening allowing the roofing material to be formed over the extensions to prevent leakage around the base.
In another embodiment of the present invention, the venting panel and the ventilation cap are constructed as a single piece. This is advantageous because the ventilation structure is easy to construct and assemble, thus reducing the costs associated with assembly, formation and construction. In addition, this embodiment allows the venting panel and ventilation cap to be formed from a single piece of sheet metal, facilitating on-site fabrication. This enables the ventilation structure to be formed and assembled on site to fit the needs of a particular roof design (both flat and sloped). As shown generally in FIGS. [0032] 5-6, in this embodiment, the invention comprises a base portion defining a central ventilation channel and a venting portion which is coupled to the base portion. Referring to FIG. 5, the venting portion defines first and second passages, wherein the first passage extends from a proximate end near the opening to a distal end. Venting panels 52 are preferably positioned below and along the outer edge of the ventilation cap 50 at the distal ends of the first and second passages, respectively. The single unit also includes another panel 54 connected to the lower face of venting panel 52 which extends back to the base of the structure 56, thereby defining a generally rectangular passageway 58 for the air to escape through. The airflow lines 60 indicate the general airflow from inside the roof structure 62 out through the ventilation structure. The base portion of the structure preferably comprises substantially parallel side walls with mounting flanges 64 that extend substantially laterally, thus allowing the structure to be adapted depending on the slope of the roof. As shown in FIG. 5, when used with sloped roofs, the base of the structure can contain sloped mounting flanges 64 with a slope substantially identical to the slope of the roof deck 66. This allows the one-piece structure to be affixed directly to the roof deck 66 (also known as the roof substrate) using nails, screws or other fastening means well known in the art. In the case of flat roofs, the slope of the sloped panels will be substantially zeroed, as shown in FIG. 6. Advantageously, regardless of whether the roof is sloped or flat, the roof may then be constructed over the mounting flanges 64 of the base to prevent leakage by laying the roofing materials (shingles etc.) directly over the sloped panels.
Referring to FIG. 6, in another embodiment of the invention for use with flat roofs, the present invention is disposed over a [0033] longitudinal opening 20 in the roof, as generally illustrated in FIG. 3. In addition, to prevent leakage, a triangular cant 68 may be secured to the base of the ventilation structure. A layer of felt 70 or other material may then be laid over the cant to provide a curved incline sloping away from the base of the ventilation structure to divert moisture and prevent leakage. A layer of flashing and or gravel may then be laid over the felt. It will be understood, however, that any of several well know roofing techniques may be employed to securely attach the present invention to the roof deck and apply a suitable roofing surface such as gravel, shingles, etc.
As described above, in the case of flat roofs, the ventilation structure of the present invention can be installed in shorter, overlapping sections to allow the roof to expand and contract to compensate for temperature variations. [0034]
Regardless of the particular embodiment employed, the present invention provides a ventilation system that is easy to install and which provides better ventilation with few, if any, dead spots. [0035]

Claims

That which is claimed:

1. A ventilation structure for use with a roof comprising a longitudinal or transverse opening defined by a roof deck comprising:

a base portion defining a central ventilation channel; and

a venting portion coupled to the base portion, the venting portion having a proximate end and first and second distal ends, wherein the venting portion defines first and second passages, wherein the first passage extends from the proximate end to the first distal end and the second passage extends from the proximate end to the second distal end, and wherein the venting portion defines first and second venting panels at the first and second distal ends, respectively, whereby air flows from the central ventilation channel through the first and second venting panels.

2. The ventilation structure of

claim 1

, wherein the base portion comprises first and second mounting flanges for mounting the ventilation structure to the roof deck.

3. The ventilation structure of

claim 2

, wherein the base portion comprise substantially parallel side walls, and wherein the first and second mounting flanges extend substantially laterally from the first and second side walls, respectively.

4. The ventilation structure of

claim 3

, further comprising at least one cant secured to the base portion that extends from one of the first and second flanges to the corresponding first or second side wall.

5. The ventilation structure of

claim 4

, further comprising a layer of insulating material formed over the cant to provide a curved incline sloping away from the base portion.

6. The ventilation structure of

claim 1

, wherein the first and second venting panels comprise ventilation openings.

7. The ventilation structure of

claim 6

, wherein the venting panel further comprises a screening material formed over the ventilation opening.

8. The ventilation structure of

claim 6

, wherein at least one of the ventilation openings comprises a perforation formed substantially laterally through the venting panel.

9. A ventilation structure for use on a roof comprising a longitudinal or transverse opening defined by a roof deck containing laterally displaced vertical extensions, the ventilation structure comprising:

first and second opposed rain closures attached to the roof deck, each rain closure comprising a face and upper and lower flanges extending from opposite ends of the face, wherein each rain closure extends between the laterally displaced vertical extensions of the roof deck, and wherein the lower flange of each rain closure is attached to the roof deck;

first and second opposed venting panels corresponding to first and second rain closures respectively, each venting panel comprising a second face disposed between upper and lower extensions, wherein the second face of each venting panel contains a ventilation opening that allows air to pass therethrough, and wherein the lower extensions of the first and second venting panels are attached to the corresponding upper flanges of the first and second rain closures; and

a ventilation cap attached to the upper extensions of the first and second venting panels, wherein the ventilation cap extends over the upper extensions of the venting panels.

10. The ventilation structure of

claim 8

, wherein at least one of the first and second venting panels is attached to the rain closure such that the face of the venting panel is offset from the face of the rain closure.

11. The ventilation structure of

claim 8

, further comprising a plurality of venting panels.

12. The ventilation structure of

claim 8

, wherein at least one venting panel comprises a plurality of ventilation openings.

13. The ventilation structure of

claim 8

, wherein the ventilation opening comprises a perforation formed laterally through a face of the ventilation cap.

14. The ventilation structure of

claim 8

15. The ventilation structure of

claim 8

, where the venting panel and the ventilation cap comprise a unitary structure.

16. A method for providing ventilation to an attic defined by a roof, wherein the roof comprises a longitudinal or transverse opening defined by a roof deck containing laterally displaced vertical extensions, the method comprising:

securing first and second rain closures, each rain closure comprising a face and upper and lower flanges extending from opposite ends of the face, to the roof deck on opposing sides of the longitudinal or transverse opening by attaching the lower flange of each rain closure to the roof deck;

securing first and second venting panels, each venting panel comprising a second face disposed between upper and lower extensions, to the first and second rain closures respectively by attaching the lower extensions of the venting panels to the upper flanges of the respective rain closures, wherein each venting panel face contains a ventilation opening that allows air to pass therethrough; and

securing a ventilation cap to the upper extensions of the first and second venting panels, wherein the ventilation cap extends over the upper extensions of the venting panels, whereby air flows through the roof opening through the ventilation openings in the first and second venting panel faces.

17. The method of

claim 16

18. The method of

claim 16

, wherein the ventilation opening further comprises a screening material formed over the ventilation opening.

19. A ventilation structure for use on a roof comprising a longitudinal or transverse opening defined by a roof deck containing laterally displaced vertical extensions, the ventilation structure comprising:

first and second opposed venting panels, each venting panel comprising a face disposed between upper and lower extensions, wherein the face of each venting panel contains a ventilation opening that allows air to pass therethrough, and wherein the lower extensions of the first and second venting panels are attached to the roofing deck; and

20. The ventilation structure of

claim 19

, further comprising a roofing material formed over the lower extension of the first and second venting panels.

21. The ventilation structure of

claim 19

, further comprising a plurality of venting panels.

22. The ventilation structure of

claim 19

23. The ventilation structure of

claim 19

24. The ventilation structure of

claim 19

25. The ventilation structure of

claim 19

, where the venting panel and the ventilation cap comprise a unitary structure.