Precast Foundation Column Assembly for Supporting a Building Frame Post

This application claims the benefit under 35 U.S.C. 119(e) of U.S. provisional application Ser. No. 63/632,253, filed Apr. 10, 2024.

The present invention relates to a precast foundation column assembly for supporting a post of a building frame thereon relative to ground.

In the construction of a post-frame building, it is common practice to form the frame of a plurality of wooden frame posts having their bottom ends set on foundation pads within respective holes in the ground such that the frame posts protrude above the ground. Roof trusses and wall framing members (also known as girts) are then connected between the protruding portions of the wooden frame posts to complete the frame of the building. To prevent degradation of the bottom ends of the wooden frame posts, at least the lower portion of the wooden frame posts should be treated.

Alternatively, U.S. Pat. No. 6,964,139 by Perma-Column, Inc. discloses an arrangement in which the wooden frame posts are replaced with a two-part post having an upper wooden portion and a lower concrete portion. The lower concrete portion is received on a separate foundation pad within a respective hole in the ground in the usual manner. To prevent the concrete post from lifting from the ground as a result of seasonal freeze and thaw of the ground, a transverse anchor pin must be inserted through the bottom of the concrete post and additional concrete must be poured on site to bond with the anchor pin.

According to one aspect of the invention there is provided a foundation column assembly for supporting a wooden post of a building frame thereon relative to ground, the assembly comprising:

By providing a precast concrete column that supports a wooden frame post thereon, the wooden frame post is separated from direct contact with the ground to minimize degradation of the wooden frame post over time. The further arrangement of the precast concrete column with a lower portion of increased dimension relative to the upper portion provides the function of a footing integral with the column that increases the load bearing capacity of the column without additional foundation pads being required to be inserted into the holes in the ground below the columns. Furthermore, the increased dimension of the lower portion relative to the upper portion acts to prevent uplift of the column in response to seasonal freeze and thaw cycles, within the need for a transverse anchor pin and additional poured concrete on site into the hole in the ground according to the prior art arrangement described above.

Preferably the upper portion spans a majority of a length of the column.

The lower portion preferably defines a footing which protrudes radially relative to the upper portion about a full circumference of the lower portion.

According to the illustrated embodiment, the cross-sectional dimensions of the lower portion are at least 50% greater than the cross-sectional dimensions of the upper portion.

Preferably said at least one connecting rod extends into the lower portion of the column. Each one connecting rod may include (i) a main rod portion extending continuously between the bracket and the lower portion of the column, and (ii) a transverse portion extending transversely to a longitudinal direction of the column within the lower portion of the column. The transverse portion is preferably spaced below a top end of the lower portion of the column.

The bracket arrangement may be further arranged for use with a plurality of wood screws for penetration into the wooden post, in which the bracket comprises a pair of plates locating a plurality of fastener apertures therein arranged to cooperate with the wood screws to fasten the bracket arrangement to the wooden post.

According to a second aspect of the present invention there is provided a method of supporting a wooden post of a building frame thereon relative to ground, the method comprising:

The method may further include providing a plurality of wood screws for penetration into the wooden post, and fastening the wood screws into the wooden post through fastener apertures in the bracket arrangement to fasten the bracket arrangement to the wooden post.

In the drawings like characters of reference indicate corresponding parts in the different figures.

Referring to the accompanying figures there is illustrated a foundation column assembly generally indicated by reference numeral. The assemblyis particularly suited for use in a post-frame buildingas described in the following.

A typical post frame buildingincludes a building frame having a plurality of wooden frame postsprimarily supported at spaced apart positions about the perimeter of the building. According to the present invention, each frame postis supported relative to groundby a respective assemblyas described in the following. A generally cylindrical holeis first formed in the ground to receive the assemblytherein such that the assembly is primarily located below grade while a portion of the assemblyprotrudes above ground for mounting the bottom end of the respective frame postthereon at a location spaced above the ground. Roof trusses are typically connected between the posts at opposing sides of the building frame. Adjacent posts are also connected by horizontal frame membersreferred to as girts that extend along the exterior of rows of posts for supporting exterior sheathingthereon to form the exterior walls of the building. Additional exterior finishing material can be supported on the exterior side of the sheathing and on the roof trusses to form the exterior walls and roof of the building.

Although various embodiments of the foundation column assemblyare shown in the accompanying figures, the features in common with the various embodiments will first be described herein.

Each foundation column assemblygenerally includes (i) an upright columncomprising a unitary concrete body extending in a longitudinal direction between a top endand a bottom endof the column, (ii) a bracketmounted at the top endof the columnfor securing the bottom end of the wooden frame postthereon, and (iii) a plurality of connecting rodsfixed to the bracketto extend into the concrete body of the columnfor connecting the bracketto the columnand for reinforcing the concrete column. Each columnincludes an upper portiondefining the top end of the column and a lower portionbelow the upper portion which extends to the bottom of the column. The upper portionmounts the bracketthereon and has a cross-sectional shape and cross-sectional dimensions perpendicular to the longitudinal direction of the column which are approximately equal to the corresponding shape and dimensions of the wooden frame post. The lower portionbelow the upper portion is increased in dimension relative to the upper portion to define a cylindrical shaped footing that is integral with the upper portion. The increased dimension of the lower portionof the column increases the load bearing capacity of the column.

The bracketof each assemblyis formed of rigid plate metal to be generally U-shaped. More particularly, the bracket includes a base platehaving rectangular dimensions which are similar to the cross-sectional shape and dimensions of the wooden frame postabove and the upper portionof the concrete columnbelow. The bracket also includes two side platesextending perpendicularly upward from opposing ends of the base plateso as to be parallel and spaced apart from one another by a distance that is approximately equal to a corresponding distance of the bottom end of the frame post received between the side plates.

A plurality of fastener apertures are located in each side platewithin an upper groupof fasteners in proximity to the top end of the side plate and a lower groupof fasteners that are spaced below the upper grouptowards the bottom end of the side plate. Each of the fastener apertures is suitably sized for receiving a wood screw inserted therethrough for threaded penetration into the wooden frame post received between the side plates while retaining the head of the screw against an outer surface of the side plate. In the illustrated embodiment, the fastener apertures have a diameter of 9/32 of an inch and each group of fasteners comprises three rows of three fastener apertures in which the apertures in each row are staggered and offset laterally relative to the apertures of the adjacent row(s).

The bracketfurther includes a stiffener platecomprising a plate of metal which is thicker than the metal forming the base plateand side platesand has dimensions similar to the base plate. The stiffener plateis secured immediately below the base plateby welding along all four edges to corresponding edges of the base plate.

The upper portionof the concrete columnhas a rectangular cross-section with cross-sectional dimensions oriented perpendicularly to the longitudinal direction that are approximately equal to corresponding dimensions of the wooden frame post to be mounted within the bracket. The upper portion spans the majority of the height of the column between the junction of the upper and lower portions at an intermediate portion of the column to the top end of the column. In the illustrated embodiment, the upper portion spans a height of approximately 5 feet; however, the upper portion may have a height between 2 feet and 8 feet in further embodiments for example.

The lower portionof the concrete column is cylindrical in shape while having a height which is much less than the height of the upper portion. In the illustrated embodiments, the lower portion has a height of approximately 6 inches; however, the lower portion may have a height between 4 inches and 6 feet in further embodiments for example. The diameter of the lower portion is much greater than the corresponding dimensions of the upper portion such that the lower portion protrudes radially outward relative to the upper portion about the full circumference of the column. In the illustrated embodiment, the lower portion has a radius of 12 inches. In this instance, the cross-sectional dimensions of the lower portion within a plane perpendicular to the longitudinal axis of the column are greater than corresponding dimensions of the upper portion and the wooden post above.

A set of four connecting rodsare provided to span the majority of the length of the column in the longitudinal direction. Each connecting rod is a metal rod welded to the stiffener plateat the bottom of the bracket to form a continuous and unitary metal body together with the bracket. In the illustrated embodiment, the four connecting rods are arranged at the corners of a rectangular pattern such that each connecting rod is associated with a respective corner of the rectangular cross-sectional shape of the upper portion of the column while being spaced inwardly from both of the adjacent sides so that each of the connecting rods is fully surrounded by the concrete material of the column.

Each connecting rodincludes a main rod portionwhich extends linearly from the bracket at the top end of the column across the full length of the upper portion of the column to terminate at an intermediate location within the lower portion of the column. The main rod portion is thus longer than the upper portion of the column. Each connecting rod also includes a transverse portionwhich is bent perpendicularly relative to the main rod portion so as to be generally horizontal in orientation within the lower portion of the concrete column. In the illustrated embodiment, the transverse portionis centrally located between top and bottom ends of the lower portion of the column. The connecting rods are arranged in pairs with each transverse portionextending from the respective rod portiontowards the other connecting rod of the associated pair. The two connecting rods of each associated pair thus collectively form a generally U-shaped arrangement with the transverse portionsthereof being located closely alongside one another.

Each assemblyis formed by initially forming the bracketfrom metal plate material and attaching the connecting rodsin the desired pattern. The upper and lower portions of the concrete column are then formed together to fully surround the connecting rods. Once the concrete material has cured, the finished assemblycan be transported from the manufacturing location of the assembly to a building site where the assemblywill be used in the construction of a building.

At the building site, a hole is formed in the ground at the location of each frame post of the frame of the building. Each precast foundation column assemblyis then placed in the respective hole in the ground so that the lower portion of the column is abutted with the bottom end of the hole. A wooden frame postis then attached to each assemblyby inserting the bottom end of the frame post between the side platesin abutment with the base platesuch that the cross-sectional shape of the frame post is substantially continuous with the upper portion of the columnbelow. Wood screws are then inserted through the fastener apertures in the upper and lower groupsandwhile penetrating and threading the wood screws into the wooden material of the postto secure the post relative to the assembly. A different number of screws can be used depending upon the size and loading of the wooden post. The holes in the ground are then backfilled with suitable backfill material, for example stone aggregate material or soil, and the backfill material is compacted about the portion of each assemblylocated below grade. The holes are typically formed in the ground at a depth that places the bracketspaced slightly above ground level resulting in the lower portion of the column being fully embedded in the ground while a majority of the upper portion of the column is embedded in the ground, but with the top end of the column protruding slightly above ground.

Turning now to, in the instance of a post formed by three plies of 2 inch×8 inch dimensional lumber, the resulting wooden frame post has cross-sectional dimensions of approximately 7 inches by 4⅝ inches. The upper portion of the concrete column corresponds to the dimension of the lumber in one direction and the combined dimensions of the lumber with the side plates of the bracket overlapping each side of the wooden frame post in the other direction such that the overall dimensions of the upper portion of the concrete column in this instance is 7 inches×5⅛ inches. The corresponding lower portion in this embodiment has a diameter of approximately 12 inches.

Turning now to, in the instance of a post formed by four plies of 2 inch×8 inch dimensional lumber, the resulting wooden frame post has cross-sectional dimensions of approximately 7 inches by 6⅛ inches. The upper portion of the concrete column corresponds to the dimensions of the lumber in one direction and the combined dimensions of the lumber with the side plates overlapping each side of the wooden frame post in the other direction such that the overall dimensions of the upper portion of the concrete column in this instance is 7 inches×6 ⅝ inches. The corresponding lower portion in this embodiment has a diameter of approximately 12 inches.

Turning now to, in the instance of a post formed by five plies of 2 inch×8 inch dimensional lumber, the resulting wooden frame post has cross-sectional dimensions of approximately 7 inches by 7⅝ inches. The upper portion of the concrete column corresponds to the dimensions of the lumber in one direction and the combined dimensions of the lumber with the side plates overlapping each side of the wooden frame post in the other direction such that the overall dimensions of the upper portion of the concrete column in this instance is 7 inches×8 ⅛ inches. The corresponding lower portion in this embodiment has a diameter of approximately 14 inches.

In the above illustrated embodiments, the cross-sectional area of the lower portion is typically between 1.5 and 5 times greater than the cross-sectional area of the upper portion, and more preferably between 2 and 3 times greater than the cross-sectional area of the upper portion. As noted above, the increased dimension of the lower portionof the column relative to the upper portionincreases the load bearing capacity of the column.

Since various modifications can be made in the invention as herein above described, and many apparently widely different embodiments of same made, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense.