Sloped concrete roof and eave system

Abstract

A sloped concrete roof and eave method and system is disclosed which can be used in commercial or residential construction. The sloped concrete roof and eave of the present invention may be formed using several concrete construction methods.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from and claims the benefit of U.S. Provisional Application No. 60/846,005, filed Sep. 20, 2006, entitled “Sloped Concrete Roof and Eave System,” which is hereby incorporated by reference.

BACKGROUND

Roof systems are all sloped or pitched to allow water to run off and drain, while providing shelter. Roof slopes fall into two categories. One category is roofs having a small slope, such as a ⅛″ rise per foot slope for flat roofs, and the other category is for roofs with a much greater slope, such as a 3″-12″ rise per foot slope.

Roofs in the first category, small slope roofs, typically use a truss or joist system for support. The roofs in this category are then typically finished using plywood, insulation, built up roofing membrane and generally have parapet walls. Commercial construction of such small slope roofs may have a poured concrete slab over metal decking which is placed above the roof joist or truss system.

When a building design calls for a roof in the second category (i.e. having a larger slope, such as 5″ rise per foot), however, concrete slab is generally not considered for a umber of reasons. The methods for forming such roofs and the structural requirements of such roofs can be very costly and time consuming. One such obstacle is the horizontal force exerted on the walls from the sloped roof. Special supports and connectors have been devised to address this issue in known roofing systems. Presently, because of these issues, buildings requiring large roof slopes are typically built using either a roof truss or roof rafter system, which is generally of wood construction.

Wood roof systems, though, are especially susceptible to damage in a storm or hurricane due to the strong winds of the storm. The wind forces that storms can generate may exceed the structural design of a wood roof system. This can result in significant roof damage and possibly roof failure. Also, because wood deteriorates, such deterioration can exacerbate the situation and heighten the possibility of roof damage during a storm. Also, because of such deterioration, wood roofing systems eventually need to be replaced as well.

Steel truss or joist systems are stronger than wood and typically provide better protection against the damage that such storms can cause. However, roof finishes do not differ of those of wood and steel truss roof systems and are still susceptible to damage during storms or hurricanes, and such damage can compromise the integrity of the building. Concrete roofing systems are an alternative, but to date, these concrete roof systems have only been used on a limited basis and are not favorable for production housing construction. Current concrete roof designs are limited by their structural design and also by the manner in which they are made or formed. This process is typically slow and cumbersome. These obstacles make concrete roof systems expensive to build and difficult to use in production housing construction or in other facets of construction.

Accordingly, there is a need for a concrete roofing system that can be produced more effectively and efficiently which can be used in a production housing construction environment, with benefits for commercial and residential construction as well.

SUMMARY

According to one aspect of the present invention, a building system with a sloped concrete roofing and eave includes a number a plurality of floor slabs; a number of concrete sidewalls having a formed concrete eave formed thereon, wherein the concrete sidewalls are connected to the plurality of floor slabs; and a concrete roof, wherein the concrete roof is integrated with the formed concrete eave. The sidewalls, the concrete eave and the concrete roof of the building system may be poured in place, integral with one another. The concrete roof of the building system may include a truss system, a number of purlin members or a number of polystyrene panels. The concrete eave of the building system may also be poured in place with the sidewalls and the concrete roof may be precast, wherein the precast roof is connected to the poured in place concrete eave.

According to another aspect of the present invention, a method for constructing a building with a sloped concrete roof and connected eave includes providing an eave form, a sidewall form and a roof support form, wherein the eave form, sidewall form and roof support form interconnect with one another to allow the free flow of concrete between the forms. The method also includes pouring concrete into the roof support form, the eave form and the sidewall form; and allowing the concrete to cure to an appropriate stripping strength to form a sloped concrete roof, a concrete eave and a concrete sidewall. The method may also include providing a roof truss system, wherein the roof support form is supported with the roof truss system or wherein the roof support form is supported with a hydraulic lift. The method may also include using a tunnel construction system, insulated concrete form system, handset form system or gang form system to support the roof support form, the eave form and the sidewall form. The roof support form of the method may include purlin members or polystyrene panels. The method may also include a precast roof, eave or sidewall. The method may also include the use of a strap connector, wherein when the concrete is poured and the concrete cures, the strap connector connects the roof truss system and the concrete eave.

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 single family building with an embodiment of a sloped concrete roof of the present invention;

FIG. 2 is a plan view of a multi-family building with an embodiment of a sloped concrete roof of the present invention;

FIG. 3A is a perspective view of an embodiment of a roof of the present invention with portions of the roof removed for illustration purposes;

FIG. 3B is a cross section along the line 3B-3B of FIG. 1, illustrating a cast-in-place roof and eave using aluminum forms and a truss system;

FIG. 3C is a cross section along the line 3C-3C of FIG. 1, illustrating a cast-in-place roof and eave using aluminum forms and a truss system;

FIG. 3D is a section detail of a cast-in-place roof and eave using aluminum forms and a truss system;

FIG. 4A is a cross section along the line 4A-4A of FIG. 2, illustrating a cast-in-place concrete roof and cave in a tunnel form construction system using a roof truss system;

FIG. 4B is a cross section along the line 4B-4B of FIG. 2, illustrating a cast-in-place concrete roof and eave in a tunnel form construction system using a roof truss system;

FIG. 4C is a section detail of the cast-in-place concrete roof and eave in a tunnel construction system using a truss system;

FIG. 4D is a section detail of the cast-in-place concrete roof and eave in a tunnel construction system using a truss system table with the polystyrene panels running perpendicular to the perimeter wall;

FIG. 5A is a cross section of a two story building similar to the cross section in FIG. 4A illustrating a cast-in-place concrete roof and eave in a tunnel form construction system using a hydraulic table;

FIG. 5B is a cross section of a two story building similar to the cross section in FIG. 4B illustrating a cast-in-place concrete roof and eave in a tunnel form construction system using a hydraulic table;

FIG. 5C is a section detail of the cast-in-place concrete roof and eave in a tunnel construction system using a hydraulic table;

FIG. 5D is a section detail of the cast-in-place concrete roof and eave in a tunnel construction system using a hydraulic table with the polystyrene panels running perpendicular to the perimeter wall;

FIG. 6A is a cross section of a two story building similar to the cross section in FIG. 4A illustrating precast roof panels and a cast-in-place eave in a tunnel form construction system;

FIG. 6B is a cross section of a two story building similar to the cross section in FIG. 4B illustrating a precast roof panel and a cast-in-place eave in a tunnel form construction system;

FIG. 6C is a section detail of the precast concrete roof panel and cast-in-place concrete eave in a tunnel construction system;

FIG. 7 is a section detail of a cast-in-place concrete roof and eave using insulated concrete forms and truss system;

FIG. 8 is a section detail of a cast-in-place concrete eave and wall using insulated concrete forms and precast concrete roof panels and truss system;

FIG. 9 is a section detail of a cast-in-place concrete eave and wall using aluminum forms and precast concrete roof panels and truss system; and

FIG. 10 is a section detail of a precast concrete roof and eave and truss system.

DETAILED DESCRIPTION

The embodiments of the invention disclosed herein include a cast-in-place and pre-cast concrete roof, eave and wall system. The concrete roof and eave system embodiments include the use of, but are not limited to using, steel or aluminum forms, polystyrene panels and truss systems. In these embodiments, the foundation system, generally concrete footings and/or monolithic concrete floor slabs, are set. If more than one story is being built, the lower level floors and walls are set braced and shored. Once the last floor is set, the forms are placed along with a truss system to serve as a temporary shoring device. After the trusses and forms have been set and secured, polystyrene panels and steel reinforcements are placed and concrete is poured to create the roof slab, concrete eave, and walls. When the concrete is cured, the forms are removed. The roof can now be finished using conventional shingles, tiles or an aluminum roof system.

Referring to FIG. 1, a roof 10 of an embodiment of the invention is depicted. The roof 10 is typically supported by bearing walls 12, as it is in this embodiment. The roof 10 of this embodiment includes hips 14, ridges 16, valleys 18, gables 20 and eaves 22. The eave 22 is the part of the roof 10 that extends past the walls 12. Referring now to FIG. 2, a multi-family residence is illustrated. In multi-family residences, units are generally divided by party walls 24.

Referring to FIGS. 3A-3D, a preferred embodiment of the invention is depicted. FIGS. 3A-3D illustrate a monolithic cast-in-place concrete roof 10, eave 22 and wall 12 arrangement formed using concrete wall forms 50, 52 (FIG. 3B) (industry termed handset or gang forms) along with an eave form 54. A two story building is illustrated, but it should be understood that the design is not limited to single or two story building. Referring specifically to FIG. 3B, in this embodiment, lower level walls 12 and floors 26 are first poured and cured. Then, upper wall steel reinforcements are placed. Interior and exterior wall forms 50, 52 and eave forms 54 are then set and braced. All wall openings are blocked during the setting of the forms 50, 52, 54. In this embodiment, a pressure treated wood blocking 55 (FIG. 3D) is secured to the eave form 54 and used as a nailer for drip edge or for gutter installation.

Once all forms 50, 52, 54 are set and braced, roof trusses 60 are set on top of the wall forms 50, 52. The truss 60 has a bottom chord 62 which can be used as a collar tie to balance the horizontal thrust of the concrete roof 10. In this embodiment, this is done by attaching readily available strap connectors 64 to the bottom chord 62 and positioning the strap connectors 64 so that when the concrete is poured, the strap connectors 64 are embedded into the concrete wall 12 and eave 22. Blocking inserts are placed between the trusses 60 to close any openings. In this embodiment, purlin members 66 are perpendicularly placed on top or between the roof trusses 60 for added rigidity. The purlin members 66 also provide for the placement of polystyrene panels 68 on the roof 10. In this embodiment, polystyrene panels 68 are placed and screwed to the purlin bracing members 66. The purlin bracing members 66 hold the panels 68 in place so a construction crew can set appropriate steel reinforcements.

At this point in the process, all bracing and shoring posts are placed. Next, in this embodiment, flowable concrete is pumped into the forms 50, 52, 54 to form the remaining wall portions 12, the eave 22 and a roof surface 70. Once poured, the concrete is then properly sloped and smoothed in a conventional manner, using screed boards and masonry tools. After the poured concrete has cured, all bracings, shoring, and forms are removed, and the building is ready for finishing.

Referring to FIGS. 4A-4D, an alternate embodiment of the invention is depicted. FIGS. 4A-4D illustrate a monolithic cast-in-place concrete roof surface 10, walls 12 and eave 22 in a tunnel construction system and truss. Referring specifically to FIG. 4B, once the lower level floors 26 and walls 12 have been poured, steel reinforcement bars are set in place for the upper level walls 12. Interior forms 80, including stackable forms 82, are then placed. Once set in place, the stackable forms 82 are elevated as illustrated in FIG. 4B and secured to the opposite forms 82 with form ties. Referring now to FIG. 4C, hinged extension forms 84 and extension support forms 86 are also raised from their resting position and set in place at this time. Exterior forms 88 are then set and secured with the interior forms 80 using form ties. Concrete eave forms 54 are then attached directly to the exterior forms 88. If adjustments between adjacent eave forms 54 are necessary in this embodiment, an adjustable support arm 90 is used to make such adjustments.

In this embodiment, aluminum framed platforms 92 are set above the interior forms 80. Trusses 60 are then set above the aluminum framed platforms 92. Horizontal shoring 98 (FIG. 4B) is used for lateral stability. Polystyrene panels 94 are then set and placed running perpendicular to the party walls 24. The polystyrene panels 94 are placed in this direction to transfer the structural load to the party walls 24. (FIG. 4D depicts the polystyrene panels 94 set in a direction running perpendicular to the party walls 24.) The polystyrene panels 94 are secured to the trusses 60 below.

Steel reinforcement bars are placed as required. Also, a wood blocking 55 can be secured to the eave forms 54 to be used as a nailer for drip edges or gutters. Also, it should be noted that the eave molding 96 can have different patterns and be a removable trim part of the eave form 54.

Referring to FIG. 4B, once all of the forms have been set and the other items described above are complete, then flowable concrete is poured into the eave forms 54 and wall forms 80, 88 and onto the polystyrene panels 94 to create the roofing surface 70, the eaves 22 and the remaining walls 12. After the concrete has cured to the required stripping strength, the aluminum truss platforms 92 are removed. The extension support forms 86 are lowered against the interior forms 80, as are the extension forms 84. The stackable forms 82 are returned to a resting position as well. The exterior forms 88 and the eave forms 54 are detached from the interior forms 80 and removed from the walls 12, 24. Finally, the interior forms 80 can be removed from the building and are ready to be reused. The roof 10 is finished using conventional methods and materials.

Referring to FIGS. 5A-5D, another alternate embodiment of the invention is depicted. FIGS. 5A-5D illustrate a monolithic cast-in-place concrete roof in a tunnel construction system using a hydraulic table. Referring specifically to FIG. 5B, once the lower level floors 26 and walls 12 have been poured and cured, steel reinforcement bars are set in place for the second level walls 12. As with the previously described embodiment, interior forms 80, including stackable forms 82, are then placed. Once set in place, the stackable forms 82 are elevated as illustrated in FIG. 5B and secured with form ties to the opposite forms 82. Referring now to FIG. 5C, hinged extension forms 84 and extension support forms 86 are also raised from their resting position and set in place at this time. Exterior forms 88 are then set and secured with the interior forms 80 using form ties. Concrete eave forms 54 are then attached directly to the exterior forms 88. If adjustments between adjacent eave forms 54 are necessary, an adjustable support arm 90 is used to make such adjustments.

In this embodiment, a hydraulic table 100 is then raised to a designated slope. Horizontal shoring posts 98 are set and secured against the stackable forms 82 and the hydraulic table 100 to support the interior forms against lateral forces. As above, polystyrene panels 94 are then set in place, in a direction running perpendicular to the party walls 24. As described above, the polystyrene panels 94 are placed in this direction to transfer the structural load to the walls 24. (FIG. 5D depicts the polystyrene panels 94 set in a direction running perpendicular to the party wall 24.)

Once all the forms are set, steel reinforcements are placed for the roof surface 70 and eave 22. A wood blocking 55, as before, can be secured to the eave form 54 to be used as a nailer for drip edges or gutters. Also, it should be noted that the molding 96 can have different patterns and be a removable trim part of the eave form 54.

The next step is to pour concrete into the forms 54, 80, 88 and over the polystyrene panels 94 to create the roofing surface 70, the eaves 22 and the remaining walls 12. After the concrete has cured to a stripping strength, the horizontal shoring posts 98 are removed. The extension support forms 86 are lowered against the interior forms 80, as are the extension forms 84. The stackable forms 82 are returned to a resting position as well. The exterior forms 88 and the eave forms 54 are detached from interior forms 80 and removed. The interior forms 80 can be removed from the building and are ready to be reused. The hydraulic table 82 is left in place for temporary shoring of the concrete roof 10. The roof 10 is finished using conventional methods and materials.

Referring now to FIGS. 6A-6C, another alternate embodiment of the invention is depicted. FIGS. 6A-6C illustrate a roof system having a precast concrete roof panel and a cast-in-place concrete eave and wall using tunnel construction. Referring specifically to FIG. 6B, once the lower level floor 26 and the walls 12 have been poured, steel reinforcement bars are set in place for the second level walls 12. Interior forms 80, including stackable forms 82, are then placed. Once set in place, the stackable forms 82 are elevated as illustrated in FIG. 6B and secured to the opposite forms 82 with form ties. Exterior forms 88 are then set and secured with the interior forms 80 using form ties. Concrete eave forms 54 are then attached directly to the exterior forms 88. If adjustments between adjacent eave forms 54 are necessary, an adjustable support arm 90 is used to make such adjustments.

Referring now to FIG. 6C, a support form 108 is secured by using a perforated vertical bar 104 or form tie that is secured onto the support form 108. For forms made of aluminum or steel, an optional channel 106 may be used. A spreader bar 110 is used on a preset spacing to keep the same distance between the eave form 54 and the support form 108 and is secured with the vertical bar 104 or form ties. A horizontal shoring post 98 (FIG. 6B) is set and secured against the stackable forms 82 to support the interior forms 80 against lateral forces. A wood blocking 55 can be secured to the eave form 54 to be used as a nailer for drip edges or gutters. The molding 96 can have different patterns and be a removable trim part of the eave forms 54.

Once all of the above has been completed, concrete is poured into the forms 54, 80, 88 to form the walls 12, 24 and eaves 22. After the concrete has cured to a stripping strength, the support form 108 can be removed followed by removing the spreader bar 110. The horizontal shoring posts 98 can be removed, followed by lowering the stackable forms 82 into the resting position. All the forms can now be removed. Precast concrete roof panels that form the roofing surface 70 are then hoisted into place and secured to the walls 12. The roof 10 is finished using conventional methods and materials.

There are various wall forms made of different materials such as wood or foam such as Insulated Concrete Forms (ICF) that can be used in practicing this invention. FIGS. 7-10 illustrate further alternative embodiments. FIGS. 7 and 8 illustrate roofing systems where ICF forms 108, 110, 112 are used. The forms are held together with form ties 106. FIG. 9 illustrates an embodiment where the eave 22 is cast in place using aluminum forms 114, and the roof 10 is precast. FIG. 10 illustrates an embodiment where the eave 22 and the roof 10 are both precast. For forms that cannot withstand the pressure of concrete being poured continuously into the walls and the roof, the roof may be poured separately from the walls. The eaves may be poured with the walls along with a recessed pocket to receive the trusses and minimize labor.

Precast concrete panels may substitute the cast-in-place walls or roof in any of the embodiments described above and vice versa. A ledge may be recessed into the inside of the eave to allow bearing of trusses and precast concrete panels. All collar tie strap and connectors are preferred to be embedded into the eave during casting or precasting phase of the walls.

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 building system with a sloped concrete roofing and eave, comprising:

a plurality of floor slabs;

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

a concrete roof, wherein the concrete roof is integrated with the formed concrete eave.

2. The building system of claim 1, wherein the sidewalls, the concrete eave and the concrete roof are poured in place, integral with one another.

3. The building system of claim 2, wherein the concrete roof includes a truss system.

4. The building system of claim 3, wherein the concrete roof includes a plurality of purlin members.

5. The building system of claim 3, wherein the concrete roof includes a plurality of polystyrene panels.

6. The building system of claim 1, wherein the concrete eave is poured in place with the sidewalls and the concrete roof is precast and wherein the precast roof is connected to the poured in place concrete eave.

7. A method for constructing a building with a sloped concrete roof and connected eave, comprising:

providing an eave form, a sidewall form and a roof support form, wherein the eave form, sidewall form and roof support form interconnect with one another to allow the free flow of concrete between the forms;

pouring concrete into the roof support form, the eave form and the sidewall form; and

allowing the concrete to cure to an appropriate stripping strength to form a sloped concrete roof, a concrete eave and a concrete sidewall.

8. The method for constructing a building with a sloped concrete roof and connected eave of claim 7, further comprising:

providing a roof truss system, wherein the roof support form is supported with the roof truss system.

9. The method for constructing a building with a sloped concrete roof and connected eave of claim 7, wherein the roof support form is supported with a hydraulic lift.

10. The method for constructing a building with a sloped concrete roof and connected eave of claim 7, wherein a tunnel construction system is used to support the roof support form, the eave form and the sidewall form.

11. The method for constructing a building with a sloped concrete roof and connected eave of claim 7, wherein an insulated concrete form system is used to support the roof support form, the eave form and the sidewall form.

12. The method for constructing a building with a sloped concrete roof and connected eave of claim 7, wherein a handset form system is used to support the roof support form, the eave form and the sidewall form.

13. The method for constructing a building with a sloped concrete roof and connected eave of claim 7, wherein a gang form system is used to support the roof support form, the eave form and the sidewall form.

14. The method for constructing a building with a sloped concrete roof and connected eave of claim 7, wherein the roof support form includes a plurality of purlin members.

15. The method for constructing a building with a sloped concrete roof and connected eave of claim 7, wherein the roof support form includes a plurality of polystyrene panels.

16. The method for constructing a building with a sloped concrete roof and connected eave of claim 7, further comprising:

providing a precast roof.

17. The method for constructing a building with a sloped concrete roof and connected eave of claim 7, further comprising:

providing a precast sidewall with an integrated precast eave.

18. The method for constructing a building with a sloped concrete roof and connected eave of claim 8, further comprising:

providing a strap connector connected to the roof truss system;

prior to pouring the concrete into the roof support form, the eave form and the sidewall form, positioning the strap connector between the roof truss system and the eave form, wherein when the concrete is poured and the concrete cures, the strap connector connects the roof truss system and the concrete eave.