US20080060283A1

US20080060283A1 - Concrete eave system

Info

Publication number: US20080060283A1
Application number: US11/900,229
Authority: US
Inventors: Michael Aranda
Original assignee: EH BUILDING GROUP
Current assignee: EH BUILDING GROUP
Priority date: 2006-09-13
Filing date: 2007-09-11
Publication date: 2008-03-13

Abstract

A concrete eave method and system is disclosed which can be used in commercial or residential construction. The concrete eave formed by the system and method disclosed is separate from the roof truss system and, as such, the roof truss system is not subject directly to any upward forces that might be generated on the eave. The concrete eave disclosed may be formed using several concrete construction methods. The concrete eave can be formed using precast methods or poured-in-placed methods.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from and claims the benefit of U.S. Provisional Application No. 60/844,201, filed Sep. 13, 2006, entitled “Concrete Eave System,” which is hereby incorporated by reference.

BACKGROUND

Roofs are an integral element of buildings. Generally, these roofs are constructed with engineered roof truss systems. These systems extend past the building exterior walls creating an eave. In high wind velocity areas, strong uplift and lateral forces are often generated, and these forces can damage or tear off the roof from the main structure. Because of these strong forces, trusses are often strapped, bolted or anchored to these exterior walls.
The roof system is a critical item in the design of a house. The roof system is to be designed to sustain substantial pressure exerted by hurricanes, storms and possibly tornadoes. Many buildings are designed to the minimum code requirements to reduce cost of construction. Many times, the minimum design criteria, though, can still leave a building, particularly the roof system, vulnerable to storms that generate forces stronger than those called for by minimum code requirements. During a storm, the roof can be damaged due to the uplift forces, and the roof may be compromised. The structural integrity of the building may be weakened. Wind gusts can sometimes momentarily surge under the eave, and this surge can damage eaves and soffits in a very short time. Once such damage occurs, the roof system becomes significantly more vulnerable and is susceptible to greater damage and structural failure.
Other than eliminating the eave, there are currently no acceptable alternative methods to address these issues. Due to hurricanes and tornadoes, roof systems need to be as strong as possible. Accordingly, there is a need for a stronger eave system that greatly helps maintain the integrity of the current system design.

SUMMARY

According to one aspect of the present invention, a roofing system includes a roof truss system and a concrete eave attached to a concrete sidewall, wherein the concrete eave is formed separate from the roof truss system and the roof truss system is connected to the concrete eave. The concrete eave of the roofing system may also be formed integral with the concrete sidewall. The concrete eave of the roofing system may be precast with the concrete sidewall, and the precast concrete eave may be formed on site or off-site. The concrete eave of the roofing system may also be poured-in-place.
According to another aspect of the present invention, a method for forming a concrete eave separate from a roof truss system includes providing an eave form, a sidewall form and a roof truss system; positioning the eave form and the sidewall form adjacent to one another; pouring concrete into the eave form and the sidewall form; allowing the concrete to cure to an appropriate stripping strength to form a concrete eave and a concrete sidewall; and placing the roof truss system in relation to concrete eave. The method may include connecting the roof truss system to the concrete eave. The method may further include having an aesthetic design on the formed concrete eave.
In some aspects of the method, the forms may be a tunnel construction system; an insulated concrete form system; a concrete block construction system; a handset form system; or a gang form system. The eave form of the method may include a wood blocking, wherein the wood blocking may be used as a nailer for drip edge or for gutter installation or wherein the wood blocking creates a truss bearing recess notch. The eave form may include a stiffener. The roof truss system of the method may be connected to the concrete eave using standard hurricane straps and fasteners.
According to yet another aspect of the present invention, a building includes a number of floor slabs, a number of concrete sidewalls having formed concrete eaves formed thereon, wherein the concrete sidewalls are connected to the floor slabs. The building also includes a roof truss system supported by the concrete sidewalls, wherein each concrete eave is a separate structure from the roof truss system.

DESCRIPTION OF THE DRAWINGS

These and other features, aspects and advantages of the present invention will become better understood with regard to the following description, appended claims and accompanying drawings where:

FIG. 1 is a plan view of a generic roof plan layout;

FIG. 2A is a cross section of a two story building illustrating a completed poured-in-place concrete eave in a tunnel form construction;

FIG. 2B is a section detail of the completed poured-in-place concrete eave in a tunnel form construction;

FIG. 3A is a cross section of a two story building illustrating a concrete eave in a precast concrete construction;

FIG. 3B is a section detail of the precast concrete eave in a precast concrete construction;

FIG. 4A is a cross section of a two story building illustrating a completed poured-in-place concrete eave in an ICF form construction;

FIG. 4B is a section detail of the completed poured-in-place concrete eave in an ICF form construction;

FIG. 5A is a cross section of a two story building illustrating a completed poured-in-place concrete eave in a concrete block construction;

FIG. 5B is a section detail of the completed poured-in-place concrete eave in a concrete block construction;

FIG. 6A is a cross section of a two story building illustrating a completed poured-in-place concrete eave in a handset or gang form construction; and

FIG. 6B is a section detail of the completed poured-in-place concrete eave in a handset or gang form construction.

DETAILED DESCRIPTION

A concrete eave system of the present invention removes the uplift pressure from the truss system and transfers the force to the exterior wall and decreases the lateral forces acting on the roof trusses or rafters. This quality increases the structural integrity of the building envelope and improves the building's ability to withstand hurricanes and storms. A concrete eave system provides a clean aesthetic condition as well as structural qualities.
In the disclosure herein, two main concrete eave forming methods and systems are described. One method and system is a precast method and system, and the other method and system is a poured-in-place concrete eave method and system. The precast concrete cave method typically includes the use of a monolithic precast concrete panel with an eave either brought to a construction site or fabricated on site and erected to form the exterior building walls, and it is formed with a notch and an embedded strap to accept roof trusses or rafters. The poured-in-place concrete eave method and system is typically poured monolithically with the exterior solid concrete walls or with concrete block with concrete filled cell. A poured-in-place concrete eave system is typically accomplished by using fabricated steel or aluminum forms. Wood forms can be used, but are limited due to reusability and precision. A notch is also used in these methods to eliminate the use of ledgers, which decreases the expense of additional materials and labor.
Referring to FIG. 1, a roof 10 typically includes a roof perimeter 12 along with typical roof ridges 13 and roof valleys 14. Also, the roof 10 typically includes perimeter walls 15 and demising walls 11. The concrete eave of the present invention is formed in the area between the perimeter wall 15 and the edge of the roof perimeter 12.
Referring to FIGS. 2A and 2B, a preferred embodiment of the invention is depicted. FIGS. 2A and 2B illustrate a monolithic poured-in-place concrete eave in a tunnel construction. It should be understood that the design is not limited to a single story or two story building. Referring specifically to FIG. 2A, in this embodiment of the invention, floor slabs 110, 111 are first poured. Once the floor slabs 110, 111 have been poured, reinforcement bars 121 are set in place for the walls. Interior forms 131, 141 are placed and then followed by exterior forms 132. Concrete eave forms 140 used in this embodiment of the invention are directly attached to the exterior forms 132. FIG. 2B illustrates a concrete eave formed in this embodiment of the invention in detail.
Referring to FIG. 2B, in this embodiment, a pressure treated wood blocking 181 is secured to the eave form 140 and used as a nailer for drip edge or for gutter installation. In this embodiment, after the interior forms 131, 141 and the exterior forms 132, 140 are set, a spreader bar 143 is set and secured. After all the forms have been secured, reinforcement bars 164 are placed for the roof slab. A stiffener 142 is connected to the eave form 140. The stiffener 142 helps support the weight of the poured concrete and can be adjustable to correct any alignment needed between forms for a continuous leveled horizontal line. The support form 141 is secured by using a perforated vertical pin 145 or a custom perforated form tie. In this embodiment, the pin 145 is screwed to a lug nut 149 and then nailed to the form. For forms made of aluminum or steel, an optional channel 148 can be used. The spreader bar 143 is used on a preset spacing to keep the same distance between the back and front and is secured by using wing nuts 144 fitted on top of the vertical bar 145 or form tie.
At this point, the concrete can be poured to fill the forms and create the walls 120, a slab 112, and an eave 125 all at once. All forms are removed after the concrete has cured to the appropriate stripping strength. Depending on the eave form 140, the eave 125 may have an aesthetic design 150 when complete. The pressure treated wood blocking 181 is left in place. The roof truss system 184 is placed above the slab 112, strapped and finished using conventional methods. The roof truss system 184 is separate from the concrete eave 125 and not subject directly to any upward forces that might be generated on the eave 125.
Referring to FIGS. 3A and 3B, an alternate embodiment of the concrete eave system of the present invention is depicted. In this embodiment, concrete eaves in a precast construction system can be achieved by precasting a monolithic precast concrete panel 221 with an eave 225. The monolithic precast panels 221 with eaves 225 are casted either on site or off-site at a concrete casting facility using casting forms. Referring specifically to FIG. 3A, once the floor slabs 210, 211 have been poured, the panels 221 are erected and placed on the slab 210 and supported by conventional shoring methods. The panels are then bolted or welded together to adjacent panels and floor systems using conventional methods as well. A pressure treated wood block 281 (FIG. 3B) is added during the casting process and can be used as a nailing area for drip edge or gutter installation.
After the precast panels 221 with eaves 225 are set, the shoring can be removed, and the roof truss system 284 can be installed. The precast panels 221 with eaves 225 are pre-notched to accept the truss system. The trusses 284 are secured by using a through bolt 271 and a roof strap 270 that is embedded into the precast panel 221 with eave 225. As with the previously described embodiment, the roof truss system 284 is separate from the concrete eave 225 and not subject directly to any upward forces that might be generated on the eave 225.
Referring to FIGS. 4A and 4B, another alternate embodiment of the concrete eave system of the present invention is depicted. In this embodiment, a poured-in-place concrete eave can be formed with Insulated Concrete Forms, also known as ICF, construction systems. Referring specifically to FIG. 4A, in this embodiment of the invention, floor slabs 310, 311 are first poured. Once the floor slabs 310, 311 have been poured, in this embodiment, ICF wall forms 331, 332 are set in place and are supported using conventional shoring methods. Eave forms 340 are then mounted to the ICF forms 331, 332 prior to the concrete being poured. Form ties 346 are used to hold the eave form 340 and ICF forms 331, 332 together in this embodiment.
Referring to FIG. 4B, in this embodiment, a pressure treated wood blocking 382 can be attached to the ICF form 331 to create a truss bearing recess notch. Also, a pressure treated wood blocking 381 is secured to the eave form 340 and used as a nailer for drip edge or for gutter installation. A spreader bar 343 is set and secured with wing nuts 344. Also, an adjustable stiffener 342 is aligned with the adjacent portions of the eave form 340. With the forms set, the concrete is poured to form an eave 325 and a wall 320. Depending on the form 340, the eave 325 may have an aesthetic design 350 when complete. All forms are removed after the concrete has cured to the appropriate stripping strength. The roof truss system 384 is eventually placed in the recessed notch and secured by using a through bolt 371 and a roof strap 370 that is embedded during the pouring phase. As with the previously described embodiment, the roof truss system 384 is separate from the concrete eave 325 and not subject directly to any upward forces that might be generated on the eave 325.
Referring to FIGS. 5A and 5B, another alternate embodiment of the concrete eave system of the present invention is depicted. In this embodiment, a poured-in-place concrete eave can be formed with a concrete block construction system. Referring specifically to FIG. 5A, in this embodiment, concrete blocks 420 are set to create the exterior walls after the floor slabs 410, 411 are poured. Referring now to FIG. 5B, a ledger 448 is used to set the height of an exterior eave form 440. The eave form 440 is then mounted to the concrete wall 420 and fastened. Plywood 480 can be used as the inside form. The plywood 480 is secured to the concrete block using assorted fasteners 491. At this point, the reinforcement bars 464 can be placed. Pressure treated wood blocking 482 can be attached to the plywood to create a truss bearing recess notch. Also, a pressure treated wood blocking 481 is secured to the eave form 440 and used as a nailer for drip edge or for gutter installation. A spreader bar 443 is set and secured with a wing nut 444 and a fastener 491. An adjustable stiffener 442 is also set and can be aligned with the adjacent portions of eave form 440. With the forms set, concrete is poured to form the concrete eave 425 and fill the cavity cells 426 of the concrete blocks. Depending on the form 440, the eave 425 may have an aesthetic design 450 when complete. The concrete is allowed to be cured prior to removing the forms and plywood. The roof truss system 484 is eventually placed in the recessed notch and secured by using a through bolt 471 and a roof strap 470 that is embedded during the pouring phase. As with the previously described embodiment, the roof truss system 484 is separate from the concrete eave 425 and not subject directly to any upward forces that might be generated on the eave 425.
Referring to FIGS. 6A and 6B, another alternate embodiment of the concrete eave system of the present invention is depicted. In this embodiment, a poured-in-place concrete eave can be formed with a handset, gang forms or similar systems. Referring specifically to FIG. 6A, in this embodiment of the invention, floor slabs 510, 511 are first poured. Once the floor slabs 510, 511 are poured, reinforcement bars 564 (FIG. 6B) are put in place. Referring to FIG. 6B, handset or gang forms 531, 532 are then set in place and supported using conventional shoring methods. An eave form 540 is then mounted to the handsets or gangs 531, 532. Form ties 546 are used to hold the eave form 540 and handset or gang forms 531, 532 together. Pressure treated wood blocking 582 can be attached to the handset or gang form 531 to create a truss bearing recess notch. A pressure treated wood blocking 581 is secured to the eave form 540 and used as a nailer for drip edge or for gutter installation. A spreader bar 543 is set and secured with wing nuts 544. An adjustable stiffener 542 is aligned with adjacent portions of the eave form 540. Once the forms are set, the concrete is poured to form the concrete eave 525 and a wall 520. All forms are removed after concrete has cured to the appropriate stripping strength. The roof truss system 584 is eventually placed in the recessed notch and secured by using a through bolt 571 and a roof strap 570 that is embedded during the pouring phase. As with the previously described embodiment, the roof truss system 584 is separate from the concrete eave 525 and not subject directly to any upward forces that might be generated on the eave 525.
While the invention has been discussed in terms of certain embodiments, it should be appreciated that the invention is not so limited. The embodiments are explained herein by way of example, and there are numerous modifications, variations and other embodiments that may be employed that would still be within the scope of the present invention.

Claims

1. A roofing system, comprising:

a roof truss system; and

a concrete eave attached to a concrete sidewall, wherein the concrete eave is formed separate from the roof truss system and the roof truss system is connected to the concrete eave.

2. The roofing system of claim 1, wherein the concrete eave is formed integral with the concrete sidewall.

3. The roofing system of claim 2, wherein the concrete eave is precast with the concrete sidewall.

4. The roofing system of claim 3, wherein the precast concrete eave is formed on site.

5. The roofing system of claim 3, wherein the precast concrete eave is formed off-site.

6. The roofing system of claim 2, wherein the concrete eave and the concrete sidewall are poured-in-place.

7. A method for forming a concrete eave separate from a roof truss system, comprising:

providing an eave form, a sidewall form and a roof truss system;

positioning the eave form and the sidewall form adjacent to one another;

pouring concrete into the eave form and the sidewall form;

allowing the concrete to cure to an appropriate stripping strength to form a concrete eave and a concrete sidewall; and

placing the roof truss system in relation to concrete eave.

8. The method for forming a concrete eave of claim 7, further comprising:

connecting the roof truss system to the concrete eave.

9. The method for forming a concrete eave of claim 7, wherein the formed concrete eave has an aesthetic design.

10. The method for forming a concrete eave of claim 7, wherein the sidewall form is a tunnel construction system and the eave form is connected to the tunnel construction system.

11. The method for forming a concrete eave of claim 7, wherein the sidewall form is an insulated concrete form system and the eave form is connected to the insulated concrete form system.

12. The method for forming a concrete eave of claim 7, wherein the sidewall form is a concrete block construction system and the eave form is connected to the concrete block construction system.

13. The method for forming a concrete eave of claim 7, wherein the sidewall form is a handset form system and the eave form is connected to the handset form system.

14. The method for forming a concrete eave of claim 7, wherein the sidewall form is a gang form system and the eave form is connected to the gang form system.

15. The method for forming a concrete cave of claim 7, wherein the eave form includes a wood blocking.

16. The method for forming a concrete eave of claim 15, wherein the wood blocking is used as a nailer for drip edge or for gutter installation.

17. The method for forming a concrete eave of claim 15, wherein the wood blocking creates a truss bearing recess notch.

18. The method for forming a concrete eave of claim 7, wherein the eave form includes a stiffener.

19. The method for forming a concrete eave of claim 8, wherein the roof truss system is connected to the concrete eave using a through bolt and a roof strap.

20. A building, comprising:

a plurality of floor slabs;

a plurality of concrete sidewalls having formed concrete eaves formed thereon, wherein the concrete sidewalls are connected to the plurality of floor slabs; and

a roof truss system supported by the concrete sidewalls, wherein each concrete eave is a separate structure from the roof truss system.