Insulated Concrete Wall Tie System

This invention relates to poured concrete walls, and particularly to apparatus and a method for forming insulated poured concrete walls.

The forming of foundation/basement walls of poured concrete is conventional. To form a poured wall, forms are secured together astraddle a space which is later filled with uncured concrete. The concrete is then left to solidify and cure, the forms are removed, and the notched protruding ends of the metal ties which were used to secure the forms together are knocked off as with a hammer. If these ends of the ties are not removed, thermal conductivity thereof causes excess heat transfer with resultant increased energy usage. Even with the tie ends removed, the concrete walls conduct sufficient heat to cause considerable extra energy use.

Therefore, thermal insulation is sometimes applied to the cured concrete walls as by spraying it on, or a layer of insulation may be glued to the inside and/or outside wall surfaces. These insulation application processes, however, involve considerable added time and labor, so that normally the walls remain uninsulated. Yet, application of thermal insulation is particularly advantageous for decreasing energy costs. Indeed, in some jurisdictions the R value must meet certain minimum requirements.

An object of this invention is to provide a novel apparatus and method for applying thermal insulation to one or both poured concrete walls at the time the walls are poured. One or two insulation panels of selected thickness are specially retained in proper position on the inside walls of the forms so as to be on the inside and/or outside surfaces of the poured wall. Then the concrete is injected, e.g., poured into the forms and against the insulation, cured, and the forms later removed. The result is that the wall is already insulated to the extent desired, i.e., subsequent insulation application steps are not necessary. The apparatus employed includes novel ties which not only secure the forms in spaced relationship, but which are longer than the conventional ties, having special insulation retention means attached thereto for retaining foam insulation layers or panels in position against the forms, adjacent the space to receive the poured concrete, so that the uncured concrete is formed directly against the insulation layer or layers. The insulation panels are retained in position by strips, preferably elongated, low-heat conductance, F-shaped strips as of polymer, these strips being held to the ties by transverse retainers. In one embodiment, these transverse retainers comprise insertable pins such as nails which fit into openings through the strips, and matching openings through the ties. In another embodiment, these transverse retainers take the form of a pair of ears integrally formed from the ties and extending into orifices in the strips.

When the forms are ultimately removed, the strips remain on the finished wall with the insulation panels, serving as a base for attaching drywall screw fasteners, for example. The added components including strips and insulation do not interfere with the ability to knock the extended notched ends of the ties off the poured wall.

The novel method involves attachment of strips to the concrete forms to hold insulation layers, insertion of one or two layers of insulation as desired, preferably self supporting foam insulation panels, against the inside walls of tile forms, with their edges retained in the strips and their inside face adjacent the space to receive the poured concrete, the strips holding the layers or panels of insulation while pouring the concrete into the space and against the insulation layer or layers. Subsequently the concrete is cured, and tile forms removed while leaving tile strips with the insulation. Eventually, the notched ends of the ties are broken off.

These and other objects, advantages and features of the invention will become apparent upon studying the following specification in conjunction with the drawings.

FIG. 1 is a side elevational view of a section of foam insulated concrete wall with strips in place;

FIG. 2 is a top plan view of the wall in FIG. 1, but with the concrete forms still in place;

FIG. 3 is an end elevational view of the F-strip shown in FIGS. 1 and 2;

FIG. 4 is a fragmentary front elevational view of the strip in FIG. 3;

FIG. 5 is a side elevational view of one embodiment of the novel form tie;

FIG. 6 is an end elevational view of the form tie in FIG. 5;

FIG. 7 is a top plan view of another embodiment of the novel form tie; and

FIG. 8 is a front elevational view of the tie in FIG. 7.

Referring now specifically to the drawings, in FIG. 1 is depicted a portion of a poured concrete wall assembly 10 formed in accordance with this invention, the elevational view representing either tile inside or outside wall portions, there being visible two adjacent insulation panels or layers 12 having their adjacent edges enveloped by and straddling a pair of strips 14 positioned back-to-back. Between these strips and insulation panels 12, the ends of a plurality (here six) of elongated, transverse, metal form ties 16 extend through and from the poured concrete wall against which the insulation and strips are retained.

Each of elongated strips 14 is preferably of the F-shaped configuration depicted in FIGS. 3 and 4, having a U-shaped socket portion formed of a pair of parallel spaced extending legs 14a and 14b and a cross leg 14d therebetween, and including a flange 14c extending beyond this U-shaped configuration and in effect being an extension of cross leg 14d. Flange 14c has one or more orifices or openings 14e therethrough for receipt of transverse fasteners such as pins 20 in tile form of nails or the like, in a manner to be described more fully hereinafter. Openings 14e in the strip are spaced at vertical intervals corresponding to the vertical spacing of the tie bars 16. These strips are formed of a low thermal conductivity material, preferably a polymeric material such as polyvinyl chloride, polyethylene, polypropylene, nylon, or any of several other available materials. The strips can be formed by a conventional extrusion process, and cut to selected length to match the height of the wall to be formed. The strips can also be easily cut on the job site to a particular length as desired.

The preferred strips are those of F-shape as noted and shown, including the U-shaped channel or socket, and the extended flange. Conceivably other configurations could be employed. For example, U-shaped strips would serve to receive and retain the insulation panels. Attachment of the strips to the tie bars could be through the cross leg of the U so as to tend to protrude somewhat into the channel and possibly be undesirable. Attachment could also be by way of a double faced tape so as to adhere to the tie bars and/or to the forms.

Another alternative is to have the strips attached to the insulation prior to placement in the forms, and even by the insulation manufacturer. Such attachment could be by adhesive. Instead of the preferred strips, the insulation could be made with an adhesive edge, covered with a removable protective sheet, for adherence to the tie bars and/or the forms.

The strips 14 could also be attached to the forms instead of, or in addition to, attachment to the tie bars.

Optionally, the top and bottom edges of the insulation panels can also be encompassed with strips, e.g., U-strips, to cover them and also to provide receptors for dry wall screws, as noted by phantom lines at 21 in FIG. 1.

These novel form tie bars 16 have some characteristics in common with the conventional tie bars presently used in the trade, and some novel characteristics for functioning in this invention. One such type of novel tie bar is shown at FIGS. 5 and 6 with an alternative embodiment being shown in FIGS. 7 and 8.

Referring first to the tie bar in FIGS. 5 and 6, it has a generally rectangular cross sectional comparable to that of tie bars presently used, includes a pair of laterally elongated, i.e., generally oval-shaped, slots 16a at opposite ends thereof for receiving fastener wedges 18 of conventional type, include a central zone 16b between pairs of notches 16c astraddle this central zone 16b, and of a width between the two pairs of notches equal to the thickness of the concrete wall to be formed. This tie bar differs from a conventional tie bar in having a pair of through orifices 16d each located in center zone 16b a small distance from notches 16c. These orifices receive pins 20 (FIG. 2) as explained more fully hereinafter. These tie bars also differ from conventional tie bars in being of greater length, particularly between notches 16c and elongated openings 16a, to accommodate not only the thickness of conventional concrete forms 22, but also the thickness of the panels or layers of insulation 12. The particular length of the tie bar, and specifically its center zone, depends on the wall thickness to be formed. The length of the tie bar zones between the notches 16c and slots 16a will depend on the thickness of the insulation layer to be employed.

In the illustrative embodiment depicted in FIG. 2, insulation is provided on both the inside and outside wall surfaces of the poured concrete wall 24 being formed. This sectional view is taken at a location corresponding to one of the tie bars 16. As an alternative, insulation can, if desired, be applied to only one wall surface of the poured wall. Another variation possible is that of the insulation thickness. For example, this could be one inch, one and one-half inch, two inch, or otherwise. The socket size on the F-strip is selected to match the insulation thickness.

When practicing the method of this invention, the conventional forms 22 are first assembled in pairs in spaced parallel relationship to each other as depicted in FIG. 2, connected together with tie bars 16. Adjacent forms are tied together by extending the tapered wedge elements 18 through adjacent flanges 22a of the forms astraddle the ends of tie bars 16 in conventional manner. These wedge elements can be secured in position by nails or other pins extended through openings 18a secured in these wedge elements. Next the F-shaped strips 14 are placed vertically inside the forms, either on one or both inside surfaces of the forms, depending upon whether insulation is going to be provided on one wall surface or on both wall surfaces of the concrete wall being formed. These F-strips extend from the top to the bottom of the forms and are attached to tie bars 16 by inserting retention pins 20, e.g., nails, through openings 14e in the strips, and openings 16d in the tie bars 16. Then the appropriate number of insulation panels 12, e.g., four feet wide and the height of the forms, e.g., eight feet high, are placed with their vertical edges contained within the U-channel or socket of the F-strips, such that the outer surfaces of these insulation panels abut against the forms 22. These insulation panels are preferably formed of a foam-type, self-supporting polymer, e.g., polyurethane, polystyrene, or other expanded polymers conventionally available in the trade. The thickness of the insulation layer is chosen for the particular R value desired, with the width of the U-channel of the F-strips being correspondingly selected. Uncured concrete is then poured into the space between the insulation panels on both sides, or between insulation panels on one side and forms on the other side. The weight of the uncured concrete causes it to press against the insulation panels for a bonding effect.

After the suitable curing period has been allowed to pass for the concrete to be firm and self supporting, forms 22 are removed in conventional fashion by removing wedge locks 18. This leaves the concrete wall 24 and the adjacent layers of insulation 12, as well as the strips 14, in position as an integral part of the wall. These strips are useful for receiving dry wall fasteners, e.g., screws. The ends of tie bars 16a can be snapped off in suitable fashion as by pounding vertically with a hammer on the protruding portions, causing them to break at the notches 16c which are recessed behind the strips and insulation, i.e., at the concrete. The result is a well insulated wall not requiring any additional insulation to be sprayed on, glued on, or otherwise attached.

Referring to FIGS. 7 and 8, an alternative type of retention means is provided for securing the F-strips to the tie bars. Specifically, the tie bar 116 there depicted includes the openings 116a of conventional oval or elongated type adjacent the ends thereof, the conventional notches 116c to enable breaking off the protruding ends of the tie bars once the concrete has cured and the forms are removed. The tie bar includes a pair of integral ears 116f stamped from and extending in opposite directions adjacent each end of the central zone 116b of the tie bars to serve as strip retaining means. These ears can fit into cooperative openings, i.e., retention means, such as those shown at 14e, or slightly larger openings, in the flanges 14c of strips 14 as shown in phantom in FIGS. 7 and 8, to retain these strips in position. In using this particular type of tie bar, no pins or nails 20 need be utilized as retaining means.

Variations of the structure illustrated herein as the preferred embodiment of the invention may be apparent to those in this field once they have studied the above description. Such variations to suit a particular type of installation are considered to be within the scope of tile invention, which is intended to be limited only by the scope of the appended claims and the reasonably equivalent structures and methods to those defined therein.