Slab edge insulating form system and methods

A method of forming an insulated concrete foundation is provided comprising constructing a foundation frame, the frame comprising an insulating form having an opening, inserting a pocket former into the opening; placing concrete inside the foundation frame; and removing the pocket former after the placed concrete has set, wherein the concrete forms a pocket in the placed concrete that is accessible through the opening. The method may further comprise sealing the opening by placing a sealing plug or sealing material in the opening. A system for forming an insulated concrete foundation is provided comprising a plurality of interconnected insulating forms, the insulating forms having a rigid outer member protecting and encasing an insulating material, and at least one gripping lip extending outwardly from the outer member to provide a pest barrier. At least one insulating form has an opening into which a removable pocket former is inserted. The system may also provide a tension anchor positioned in the pocket former and a tendon connected to the tension anchor.

BACKGROUND OF INVENTION

1. Field of Invention

This invention relates to concrete slab-on-grade fabrication, and more particularly, to systems and methods for forming insulated concrete foundations.

2. Description of Relevant Art

Combining formwork with insulation improves building thermal performance by providing a concrete foundation with insulation, and speeds installation by eliminating the need to strip concrete forms after slab pour. Among the benefits of utilizing “leave-in-place” insulation forms are reduced heating season energy consumption (and associated emissions reductions) and reduced jobsite waste because disposable wood form boards are not being used.

A conventional method uses a “leave-in-place” insulation form that comprises a rigid plastic outer piece filled with foam insulation. This system requires a separate footing pour to provide a rigid anchor for the outer forms, which increases both material and labor costs. This system does not provide a continuous termite barrier to protect the building framing from termite infestation.

Integrated concrete forms, or ICFs, have recently gained widespread use. Integrated concrete forms usually consist of hollow blocks made of expanded polystyrene reinforced with metal or plastic straps. They are used to build foundation walls and even above-grade structure walls. However, the use of ICFs on standard slab-on-grade foundations common to many tract homes is limited, because ICFs require level footings and also that the two sides of the ICFs be tied together.

Conventional slab-edge insulation practice is to frame a slab foundation using wood form boards (or other materials), pour the foundation, and then remove and dispose of the forms. The slab-edge insulation for the foundation is then secured to the slab in an entirely subsequent operation. Thus, conventional slab-edge insulation practice requires three distinct processes and often three different visits to the home site to perform each of the three processes, respectively.

What is needed are systems and methods for forming insulated concrete foundations that eliminate two of those processes. What is needed is a cost effective system to integrally form and insulate concrete slab foundations while providing pest resistance and the ability to work with post tension slab techniques that have become commonplace in many areas of the country. What is needed are leave-in-place slab-edge insulated forms that are robust, simple to install, and utilize corner and linear joining pieces that facilitate installation.

The above factors suggest a need and opportunity for improved systems and methods for forming insulated concrete foundations that reduce costs and enhance installation reliability.

SUMMARY OF INVENTION

The present invention is directed to improved systems and methods of forming insulated concrete slab foundations. In accordance with one embodiment of the invention, the form system comprises 12 foot lengths of foam panels, such as in 12-foot lengths, that enclose insulation material in a rigid covering for stiffness, protection, and UV durability. The system provides for joining adjacent forms using connectors to form a perimeter of a foundation. Methods are also provided for integrating post tension hardware.

In embodiments, a system for forming an insulated concrete foundation is provided, the system comprising a plurality of interconnected insulating forms. The insulating forms having a rigid outer surface encasing an insulating material, and an inner side surface with an upper gripping lip and a lower gripping lip extending therefrom. The upper lip is positioned on the inner side surface to provide a pest barrier.

A system for forming an insulated concrete foundation as described in claim1, wherein at least one insulating form has an opening, the system further comprising a removable pocket former inserted into the opening. Positioned in the pocket former is a tension anchor and a tendon connected to the tension anchor. The tension anchor is secured to the inner side surface of the insulating forms by one or more tension anchor braces by the upper gripping lip and lower gripping lip.

In embodiments, the system for forming an insulated concrete foundation further comprises connectors for connecting adjacent pairs of insulating forms. These connectors include connecting strips and vertical couplers. The vertical couplers have a tube for receiving insulating material, and pairs of vertical fins extending from the tube to provide guides for slidingly receiving ends of adjacent insulating forms.

In embodiments, an improved method is provided for forming an insulated concrete foundation, comprising the steps of constructing a foundation frame, the frame comprising an insulating form having an opening inserting a pocket former into the opening; placing concrete inside the foundation frame; and removing the pocket former after the placed concrete has set, wherein the concrete forms a pocket in the placed concrete that is accessible through the opening. The method also comprises positioning a tension anchor inside the pocket former, and sealing the opening by placing a sealing plug in the opening or sealing material in the opening. The method may also provide creating an opening in the insulating form.

A pocket former is provided that forms a pocket in an outer surface of a concrete foundation, the pocket former being removable through an opening in an insulating form so that pocket is accessible through the opening. The pocket former has a conical portion, a cylindrical portion, and an outer surface that is threaded.

These and other objects and advantages will be apparent to those skilled in the art in light of the following disclosure, claims and accompanying drawings.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the present invention provide systems and methods for forming insulated concrete foundations. A description of these embodiments is provided with reference to drawingFIGS. 1-12.

FIG. 1illustrates a forming insulation system and associated foundation and framing components. It provides a side sectional view through the principal plane of the form and post tension anchor to show the system in place after the foundation has been poured and a wall constructed. With reference toFIG. 1, the following features of the embodiment of the system for forming insulated concrete foundations are described.

An insulating form1comprises a rigid outer member8with an inner side surface8a, an outer side surface8b, a top surfacec, a bottom surface8d, and opposing ends8e. The rigid outer member8of the form1encloses insulating material2such as but not limited to insulating foam, protecting the insulating foam from weather, ultraviolet light, and physical damage. At least one gripping lip extends outwardly from an inner side surface8aof the outer member8, such as an upper gripping lip3. In the preferred embodiment, the upper gripping lip3is positioned offset from the top and bottom of the form1to provide a pest barrier that prevents pests from reaching the structure without being detected. An additional lower gripping lip4may be provided closer to the bottom of the form1. The gripping lips3and4assist in mechanically locking the form1to the poured foundation21. The upper gripping lip3may alternatively be referred to herein as a termite strip. In the preferred embodiment, the upper3and lower4gripping lips are symmetrical in shape so that the form1is vertically symmetrical about its generally vertical midpoint.

A snap-in-place connecting strip5may be utilized to allow a second form6adjacent to the first form1to be attached to the bottom of the first form1to accommodate insulation to the bottom of the foundation footing using a similar enclosed insulation section. Alternatively, the connecting strip5can be used to attach a below grade foam without a rigid covering (not shown) as a more economical full depth solution.

In one embodiment, a sealing plug31is used to seal the opening9cut in the form to access a post tension anchor11and tendon24. In the preferred embodiment, the opening9is cylindrical to slidingly receive the pocket formers33having the configurations such as shown, for example, in FIGS.7and8.; however, other opening configurations may be utilized. A sealing cap32and grout or other sealing material33may also be used to seal the end of the post tension system to protect it from moisture intrusion and corrosion.

At the top of form1is a flashing22that directs water away from the form and foundation and is placed under the framing siding or stucco25.

FIG. 2illustrates a system in place before the foundation21is poured and exhibits further details of the system. One or more tension braces31provide a mounting point for post tension anchors11and rebar reinforcing rods32. The rebar rods32that typically run perpendicular to the tendon, are shown inside of the brace but could be positioned inside to eliminate the need for ties, etc. to hold them in place. Strips23projecting from the upper and lower gripping lips3and4allow for securement of post tension anchor braces31. A removable pocket former33protrudes through the form1and extends beyond both sides thereof to provide for the creation of a pocket in the concrete to access the anchor through the opening9in the insulating form1. In the preferred embodiment, the pocket former33is held in place via snaps34that are activated by levers35. The pocket former33is illustrated inFIGS. 7 and 8.

The insulating form1is held in place by one or more vertical foundation stakes36attached to both the adjacent insulating forms1and6; and a diagonal brace stake37. These stakes36and37rigidly hold the forms1and optional adjacent form6in place before and during foundation pouring. This attachment will preferably be made with screws. Alternate embodiments may use other fasteners such as nails or clips to perform this attachment. For example, as shown inFIG. 2, a tie down anchor26such as the Simpson Strong Tie series may be attached to the forms1and6to hold a j bolt25to anchor walls to the foundation21.

An exemplary embodiment of a system for forming an insulated concrete foundation21is provided, the system comprising a plurality of interconnected insulating forms such as, for example, forms1and6. The insulating forms1and6have a rigid outer surface encasing an insulating material2such as insulating foam. The systems have an inner side surface with an upper gripping lip3and a lower gripping lip4extending therefrom. The upper gripping lip3is positioned on the inner side surface to provide a pest barrier, a “termite stop” strip, that prevents termites from creating hidden tunnels through the foam to the wall framing25positioned above the foundation.

An exemplary embodiment provides at least one insulating form with an opening9into which a removable pocket former33is inserted. The pocket former can be a snap-in type as shown inFIG. 7or a threaded type as shown inFIG. 8. For the threaded type, an outer surface of the pocket former is threaded. The system, in embodiments, further provides a tension anchor11positioned in the pocket former33and a tendon24connected to the tension anchor11. One or more tension anchor braces31are secured to the inner side surface of the insulating forms by the upper gripping lip3and lower gripping lip4utilizing the strips23as shown inFIGS. 2 and 3.

The system also provides means for connecting adjacent insulating forms such as a connecting strip5shown inFIG. 1. In another embodiment, a vertical coupler84as shown inFIG. 10is used to connect an adjacent pair of insulating forms1and6. The vertical coupler84has a tube portion85for receiving insulating material, a first pair of vertical fins86extending from the tube85to provide a first guide for slidingly receiving an end of a first insulating form1therebetween, and a second pair of vertical fins87extending from the tube85to provide a second guide for slidingly receiving an end of a second insulating form6therebetween. A cap88is also provided for placement on the top of the vertical coupler84. A conventional sealant (not shown) may applied to form a contiguous seal between the cap88and the first and second insulating forms1and6, respectively.

The vertical coupler84is an extruded shape with a hollow center85to allow a piece of insulation to be installed. This eliminates the need for expensive and complicated injection molds for the corners. Additionally, the vertical coupler84allows multiple form heights to be accommodated using the same tooling by simply cutting the extrusion to the proper length. For external corners, the hollow center85allows the two extruded pieces to be cut to the length on the plans for the exterior of the foundation without the need to overlap forms, simplifying form cutting and setup. The end fins86and87slide into the same tabs used by the anchor and rebar braces to hold the forms level and assist in holding the corner to the forms.

An embodiment of the system provides flashing (22inFIGS. 1 and 95inFIG. 11) positioned above a top surface of the insulating forms. An embodiment of the system shown inFIG. 11provides an insulating form94having a top that is partially sloped. The embodiment shown inFIG. 11incorporates a top edge that has a small flat surface (˜0.5″) that sits under the sheeting on the outside of the house. A sloped surface beyond this flat section slopes away from the house to facilitate drainage to meet requirements for weep screeds for stucco houses. All stucco homes must have a weep screed to facilitate drainage that begins at or below the foundation sill plate and terminates at least1inch below the sill plate. The custom flashing takes the place of the traditional weep screed and allows the form to sit outside the sill plate.

FIG. 3shows the system ofFIG. 2in an isometric view. The braces31are shown to include holes40that allow rebar32and the tension anchor11to be attached using ties, zip ties, screws, or snap features. The insulation form1is connected to identical form41by coupler42.

FIG. 4shows in more detail a coupler42that is formed of an open extrusion of rigid material. The coupler includes a top groove51and a bottom groove52to continue the termite strip protection of the insulating form shown in other Figures. Optional tabs53and54at the bottom of the coupler allow it to grip an optional second extrusion or foam beneath the top form.

FIG. 5illustrates an outer 90-degree corner62.FIG. 6illustrates an inner 90 degree corner61. These corners mimic the contour of the linear coupler42but provide for a corner to be formed. They may be constructed through a molding, extrude miter and cut, or metal bending process.

FIG. 7illustrates the preferred embodiment of a pocket former33. The tip71is formed to interface with pocket coupler11shown, for example, inFIG. 1. The annular flange72provides a positive stop on the outside of the form.FIG. 8shows an alternative embodiment of the pocket former33. In this embodiment, a coarse threading81is used to removably secure the pocket33to the form. The tip71and ring72of the preferred embodiment are used. The exemplary embodiments of a pocket former33have a conical portion33athat engages the concrete foundation to form a conical pocket, and a cylindrical portion33bthat slidingly engages the opening9in the insulating form1.

FIG. 9shows an embodiment of a sealing plug31(filled with insulation90) to seal the opening9in the form. This protects the post tension system, and maintains the insulative properties of the form at opening portions. A snap ring91and stop92provide means to hold the cap to the form in addition to potential use of adhesives. The snap ring is shown to be continuous through the revolution of the plug but an alternate embodiment could break the continuous ring into discrete sections. These snap sections could be lined up with corresponding gaps in the ring91to facilitate injection molding.

An exemplary method of forming an insulated concrete foundation is provided, which as shown inFIG. 12, comprises the steps of constructing a foundation frame S1000, the frame comprising an insulating form having an opening; inserting a pocket former into the opening S3000; placing concrete inside the foundation frame S5000; and removing the pocket former after the placed concrete has set S6000so that that the concrete forms a pocket in the placed concrete that is accessible through the opening. The method also comprises positioning a tension anchor inside the pocket former S4000; and sealing the opening S7000by placing a sealing plug in the opening or placing a sealing material in the opening. The method may also provide creating an opening in the insulating form S2000.

Although the subject matter of this application has been described with reference to various exemplary embodiments, it is to be understood that the subject matter is not limited to the exemplary embodiments or constructions. To the contrary, the subject matter of this application is intended to cover various modifications and equivalent arrangements. In addition, while the various elements of the exemplary embodiments are shown in various combinations and configurations, others combinations and configurations, including more, less, or only a single element, are also within the spirit and scope of the invention.