Abstract:
A safety barrier is formed of framing, including a guard rail that defines the infill below the rail without the use of pickets. The infill is covered with mesh screen, which may be made of nylon which has greater tensile strength than conventional fiberglass. The mesh screen is held to the framing by an extruded base. The base has a central channel between two flat spline grooves. Flat splines hold mesh screen in their respective grooves more securely than conventional friction-based channel splines. A metal plate is positioned in the central channel to enables screws that secure the base to be tightened to hold it to the framing better. The elimination of pickets in the infill leaves the view unobstructed and allows other treatments of that portion of a deck or porch that are more aesthetically pleasing without compromising safety.

Description:
TECHNOLOGICAL FIELD 
     The disclosure relates generally to the decks and porches. In particular, it relates to the infill below the guardrails of decks and porches. 
     BACKGROUND 
     A deck or porch can extend the livable area of a home considerably. Because decking and porches are oftentimes elevated with respect to the surrounding ground, the risk of falling off the deck or porch must be considered. Commonly, a guard rail is constructed at about waist height to prevent falling. However, a child or a seated adult could still fall from the deck despite the guard rail. To prevent this type of injury, pickets, narrow spaced-apart pieces of lumber, are fastened perpendicularly to the guardrail. Even in porches where typical mesh screening is attached below the guard rail, pickets are nonetheless necessary for safety because mesh screening cannot be counted on to prevent someone from falling off the porch or deck. Mesh screening may tear or come loose when subjected to lateral impact. 
     The area below the guard rail in a porch is referred to as infill. Two typical building code requirements apply to the infill. First, the infill section must be able to prevent a sphere of 10 cm (4 inches) from passing through any part of the infill. Second, when a 125-pound load is applied to a one-square-foot area, from either direction, the infill must not disengage from its framework. Pickets will meet that requirement when placed not more than 4 inches (10 cm) apart. Unfortunately, pickets partially obstruct the view from the deck and are an inconvenience to maintain. They also foreclose any alternate, aesthetic appearance for a deck or porch. 
     An infill that is safe but avoids the use of pickets would have several useful advantages. 
     SUMMARY 
     The present disclosure describes a safety barrier for the infill area, one that withstands lateral forces and can meet code requirements, but without the use of pickets or other obstructions to the view. In particular, use of a mesh with greater tensile strength and a better securement of the mesh to the framing yields the desired strength to prevent falling. Moreover, use of the present safety barrier does not preclude other, more aesthetic treatment of the infill area. 
     The safety barrier for a deck or porch, according to the present disclosure, includes framing that defines an opening, which is the infill area. A mesh screen having plural strands of at least one material cover the opening. The material is selected to have a greater tensile strength than conventional screening material, which is fiberglass. A convenient choice for the present material is nylon. Other materials can be used including a mixture of conventional screening material and stronger materials in a suitable pattern that provides sufficient overall tensile strength. 
     To hold the mesh screen to the framing, a base is attached to the framing. The base provides greater resistance to the pull on the mesh from a lateral impact. The base is configured with at least one spline groove and a central channel parallel to and between plural spline grooves. Each spline groove has a spline. The splines are not round and do not hold the marginal portion of the screen by friction. Rather they are flatter and longer and the spline groove is larger in its interior than at its entrance. There is thus an overhang at the entrance and the entrance is just large enough for the edge of the spline groove to be inserted and then rotate so that it is pressed against the overhang. In this position, the marginal portion of the mesh screen is not likely to be pulled free. 
     A metal plate may be added to the central groove to act as a washer in holding the base to framing. Fasteners, such as screws hold the base to the framing and the metal plate allows the screws to be turned more tightly without damaging the base. 
     Another aspect of the disclosure is a cap fastened to the base so it covers the base. The cap locks to the base but can be pried off. 
     Still another feature of the invention is that if pickets are not needed, so a more decorative treatment of the space between the guard rail and the balance of the framing can be used. 
     These and other features and their advantages will be apparent to those skilled in the art of porch construction and screening from a careful reading the detailed description accompanied by the following drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the Figures 
         FIG. 1  is a portion of a porch wall showing upper portions and lower portions with two types of mesh screen, according to an aspect of the disclosure; 
         FIG. 2  is a detail of the lower portion showing the guard rail mesh screen attached to the framing elements, according to an aspect of the disclosure; and 
         FIGS. 3A, 3B, and 3C  show a sequence of views of the mode of attachment of the guard rail mesh to a framing element, according to an aspect of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     A deck is a surface adjacent to a home that extends the livable space into the out-of-door. Decks are often elevated above the surrounding ground so that they are at the same level as the interior of the home. Because of that elevation, a deck may include a guard rail, set about waist height. The guard rail is supported by posts set at intervals along the perimeter of the deck. 
     In a porch that is to be covered in mesh screening, wood or other similar material is used to frame the porch, that is, structural members are installed on the porch to divide the perimeter between the porch floor and the roof over the porch into openings which are individually covered with mesh screens. 
     In both porches and decking, framing is used, for the guard rail in the instance of decks and for the exterior porch wall in the case of porches. The framing is typically made of wood structural members fastened together, including vertical posts and horizontal rails. The term framing is used herein to indicate structural, load-bearing elements, typically, but not always, made of wood, and fastened in place along the perimeter of a porch or deck and which elements when so fastened, define rectangular openings, which may include both upper openings above a rail and lower openings. Framing may be standard-sized lumber cut to convenient lengths and may be treated, stained, painted, or coated in some way to preserve the appearance and structural integrity of the framing when exposed to weather over an extended period of time. 
     In the case of both decking and porches, it is the lower openings, from and including the guard rail down, that the present disclosure is concerned. This is the infill area which becomes a safety concern when the deck or porch is elevated by more than a few feet. The particular safety concern is the risk of a fall against the infill area. 
     In the infill area, the present invention is a safety barrier that provides protection from falls through the infill. Furthermore, the protective barrier avoids the need for prior art pickets and, in addition, eliminates the obstruction of pickets to the view through the infill. 
     The primary covering is mesh screening. The term mesh screen refers to a woven product made of thin strands made of metal or plastic. The weave of the mesh is an open weave, commonly a basket weave, so that air and light may pass readily through it, but ideally, the weave is a sufficiently close to limit or prevent insects from passing through it. 
     Rather than conventional mesh screening, however, which can tear, the present barrier uses mesh screening made of a material having greater tensile strength than the conventional material used, which is fiberglass. Many stronger materials exist. For the present mesh screen where greater tensile strength is required, nylon, polyester, bronze, para-aramids, and carbon fiber may be used. Nylon is a stronger material than fiberglass and is not unduly expensive and is readily available. As shown in  FIG. 2 , mesh  18 ′ may be made of mixtures of strands with one type of strand having a higher tensile strength or a greater thickness than the other strands of mesh  18 ′. For convenience, strands of higher tensile strength are illustrated in  FIG. 2  as thicker than strands of a material with lower tensile strength, but may have higher tensile strength as a result of a different composition regardless of thickness than the composition of the second type of strands. For example, strands of fiberglass and nylon or para-aramids may be used in a mesh-within-a-mesh design. 
     The term strand refers to a thin, long, flexible, wire-like device, that may be circular in cross section but which has a length very much greater than its diameter and which can be woven with other threads in a basket weave pattern. For example, strands of one stronger material may be used on a 10 cm by 10 cm basis, which means one vertical strand of the stronger material every 10 cm and one horizontal strand of the stronger material every 10 cm and strands of a second material between them. 
     Alternatively, other arrangements may be made such as using strands of the stronger material only in a vertical orientation and strands of the other material only in a horizontal orientations, or vice versa. Still other possibilities include the use of combinations of strands in one direction but only strands of the stronger material in the orthogonal direction, or the use of different sequences of strands  12 ,  14 , horizontally than the sequence of them used vertically. To stop insects, spacing between strands  12  and  14  must remain small enough, for example, at most a few millimeters. A modest amount of experimentation can determine if a particular material or combination of material in a particular pattern is sufficient by testing it against code requirements as first stated above. 
     It is not enough for the mesh screen to be stronger, although the mesh screen must not tear when subject to lateral impact. The manner of securing the marginal portion of the mesh screening to the framing is also important. The marginal portion of the mesh screening is the portion of the mesh screen beyond that required to fit the opening that is for use in attaching the mesh screen to the framing. 
     Referring now to the figures,  FIG. 1  illustrates a portion of a guard rail  10  and framing  14  with a mesh screen  18  attached using a base  22  with a cap  26  attached to it.  FIG. 2  shows a portion of a guard rail  10  and framing  14  with a variation of mesh screen  18 ′ and with a part of cap  26  cut away to show base  22 , mesh screen  18 ′, and splines  30  more clearly.  FIGS. 3A-3C  illustrate in end views the manner in which base  22 , splines  30  and cap capture and hold mesh screen  18 . 
     To attach the present mesh screening to guard rail  10  and framing  14 , base  22  is first secured to them. Base  22  may be made of extruded material such as vinyl and formed to have spline grooves  34  for receiving the marginal portion of mesh screening. Splines  30  are used to hold the marginal portion of mesh screen  18  in spline grooves  34  and are made of synthetic or natural rubber. 
     Spline  30  may be a flat spline and spline groove  34  may be a flat spline groove with a rectangular cross section, but may more generally have a major dimension or length, a much smaller minor dimension or width at the thickest part, and a smallest dimension or height, but may not be a true rectangle in cross section. Splines  30 , as shown in  FIGS. 3A-3C , have a slightly rounded upper surface. However, splines  30  may be, for example, oval or trapezoidal, as long as they can fit through an entrance  38  in spline groove  34  and fit in interior  42 . 
     Spline grooves  34 , however, are not conventional slot-shaped grooves but have a specific shape with a relatively smaller entrance  38  than their interior  42  and a pitch so that, when spline  30  is forced inside, it will press against an overhang  46  at the outward side of entrance  38 . For example, spline groove  34  may be boot-shaped with the “toe” of the boot oriented outwards and downwards, as shown in  FIGS. 3A-3C , so that spline  30  may be oriented to have its width against the “sole” of the boot. In this position, spline  30  holds the marginal portion of mesh screen  18  mechanically rather than frictionally. The position of spline  30 , when seated, prevent it from coming out of entrance  38 . Spline  30  will not come out of interior  42  of spline groove  34  by pulling on mesh screening  18 , which, if made of a material such as nylon rather than fiberglass, must be cut to release it from base  22 . 
     Still, the present safety barrier requires that base  22  itself not break free of framing  14 . Accordingly, a central channel  50  is formed as part of base  22  and formed with plural holes  54  ( FIGS. 3A-3C ) for fasteners  58  such as screws. Moreover, a plate  62 , made of metal and also formed with holes  66  that can be placed in registration with holes  54  in central channel  54  of base  22 , is used as a washer for fasteners  58 . Plate  62  serves as a washer in that it distributes the load placed on base  22  by the tightening of fasteners  58  over a greater area of central channel  50  so that damage to base  22  from tightening is minimized. Just as importantly, because plate  62  extends under other fasteners  58  as a unit rather than under just individual fasteners  58 , it provides a more stable hold, even if some fasteners  58  pull loose, because it remains in place while other fasteners  58  are still tight. 
     Framing  14  is shown in cross-section in  FIGS. 3A-3C , together with two splines  30  and mesh screen  18  over base  22 . Mesh screen  18  is shown in an end view. Base  22  is shown attached to framing  14  with a fastener  58  running through plate  62  in central channel  50  and deep into framing  14 . 
     Above base  22  is cap  26 . Cap  26  carries on its underside two legs  72 , each with a locking foot  74 . Legs  72  are angled laterally outward. Central channel  50  is defined by two spaced apart walls  78  that are shared with spline grooves  34  and serve as the inner wall of spline grooves  34 . Walls  78  have flanges  80  that extend inwardly from the tops of walls  78  to engage locking feet  74 , as illustrated in  FIG. 3C , when cap  26  is pressed onto base  22  to lock cap  70  onto base  22 . 
     Cap  26  has trim flanges  82  that depend from its lateral ends and provide additional securement against the removal of mesh screen  18  by lateral force. 
     As tangential force is applied to mesh screen  18  in a direction indicated by the letter A as seen in  FIG. 3C , spline  30  is compressed widthwise because it is softer than base  22  and presses against overhang  46 . Further tension on mesh screen  18  pulls overhang  46  laterally but also causes the floor of base  40  to deform and squeeze spline  30  against the inner wall of interior  42 . Also, trim flanges  82  may be lifted by the force on mesh screen  18  thereby forcing legs  72  to push harder against walls  78  of central channel. The combined resistance to lateral force on mesh screen  10 , combined with its enhanced tensile strength, enables mesh screen in the infill to withstand perpendicular forces and not give way. 
     When introducing elements of the present disclosure or exemplary aspects or embodiment(s) thereof, the articles “a,” “an,” “the” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Although this disclosure has been described with respect to specific embodiments, the details of these embodiments are not to be construed as limitations.