Abstract:
Upper and lower pairs of horizontally spaced L-shaped brackets made of steel are secured via fasteners to the rear sides of spaced apart vertical studs during the framing stage of building construction. During subsequent drywall installation the pointed ends of the perpendicularly extending strap attachment portions of each bracket penetrate the drywall and project outwardly from the studs and drywall. Upper and lower sheet metal straps, each having a sequence of equally spaced holes, are cut to length so that they can partially encircle the upper and lower third of a water heater. The terminal ends of the straps are connected to corresponding ones of the strap attachment portions of the brackets and placed under tension with bolt assemblies.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to plumbing in general, and more particularly, to devices used to restrain residential water heaters. 
     States which have a high earthquake risk require that residential water heaters be secured so that they will not tip over as a result of seismic disturbances. This prevents serious injury that a person might incur if hit by a heavy water heater falling off a raised platform. Also, if the water heater tips over, the gas line will rupture, creating a severe danger of fire and/or explosion. Hawaii has a similar requirement to secure water heaters from tipping over due to high winds. 
     For example, by law in California (Section 19211(a) of the Health and Safety Code) all new and replacement water heaters sold in California on or after Jul. 1, 1991, and all existing water heaters shall be braced, anchored, or strapped to resist falling or horizontal displacement due to motion induced by earthquake. 
     Section 510.5(e) of the Uniform Plumbing Code (UPC) requires that in seismic zones three and four, water heaters shall be anchored or strapped to resist horizontal displacement due to earthquake motion. According to this section, strapping shall be at points within the upper one-third and lower one-third of its vertical dimensions, and a minimum of four inches above the controls shall be maintained relative to the lower strapping. 
     Even before laws were enacted that mandate the anchoring of water heaters, plumbers tape has been wrapped around the top third and bottom third of a residential water heaters. The tape is then nailed to the wall studs. The studs are difficult to locate and the tensile strength of such attachments is dubious, at best. 
     Various products have been specially developed and commercialized for more securely anchoring residential water heaters. The QUICK STRAP 50 (Trademark) water heater restraint manufactured by HoldRite, Inc. of San Marcos, Calif. comprises upper and lower metal straps that surround the water heater. Each strap has its opposite ends connected via lag bolts through dry wall into adjacent wall studs. Each strap has two segments which have vertical slots into which are fitted U-shaped metal brackets. The brackets are pulled together by a nut and bolt assembly. The packaging for this product indicates &#34;patent pending&#34;. A similar product with straps and tensioning buckles is sold under the trademark SPACEMAKER TS-E-25. 
     While the aforementioned commercial products may appear to provide some degree of restraint, they are often improperly installed and do not achieve their ultimate goal. Both products are installed after the drywall has been hung. Therefore, it is difficult to accurately locate the studs. Tapping the wall for sound or using a stud finder is tedious and prone to error. Frequently, the installer does not locate the center of the stud and/or drills the wrong size pilot hole. The lag bolt screwed into the pilot hole may thus not provide the desired tensile strength. Worse yet, a building inspector cannot check for correct anchoring with these devices. Frequently, the installer drills a number of test holes, requiring subsequent spackling and painting. In addition, both the aforementioned commercial products include up to sixteen feet of strap to accommodate various mounting configurations, and much of this strap ends up being wasted. 
     SUMMARY OF THE INVENTION 
     It is, therefore, the primary object of the present invention to provide an improved system for restraining a water heater to prevent the same from tipping over due to earthquake or wind induced motion. 
     It is another object of the present invention to provide an improved method for restraining a water heater to prevent the same from tipping over due to earthquake or wind induced motion. 
     It is another object of the present invention to make it easier for plumbers to comply with building codes that require the anchoring of water heaters. 
     It is another object of the present invention to reduce the amount of labor and materials required to properly restrain a residential water heater. 
     It is another object of the present invention to ensure that water heater restraints have the proper tensile strength. 
     According to the present invention, a system is provided for restraining a water heater to prevent the same from tipping over. The system includes upper and lower pairs of horizontally spaced brackets. The first bracket of each pair is secured to a rear side of a first wall stud. The second bracket of each pair is secured to a rear side of an adjacent second wall stud. The system further includes upper and lower straps for partially encircling a water heater. Connecting mechanisms, such as nut and bolt assemblies, are used to secure the ends of each strap to a corresponding bracket. 
     The method of the present invention includes the following steps. During a framing stage of construction and prior to the installation of drywall, an upper pair of horizontally spaced brackets and a lower pair of horizontally spaced brackets are installed at the proper heights on a plurality of studs adjacent a location where a water heater is to be anchored. Each bracket is secured to a corresponding one of the studs with at least one fastener. A strap attachment portion of each bracket extends in an outward direction from the stud. Next, drywall is installed over the plurality of studs in a manner that allows the strap attachment portion of each of the brackets to penetrate through the drywall. The water heater is then vertically positioned at the location between the brackets of the upper and lower pairs of brackets. An upper strap and a lower strap are cut so that each strap has a dimension that allows it to partially encircle the water heater while a pair of its terminal ends can reach the strap attachment portions of the corresponding brackets. Finally, the terminal ends of the upper strap are secured to the corresponding strap attachment portions of the upper brackets and the terminal ends of the lower strap are secured to the corresponding strap attachment portions of the lower brackets. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a diagrammatic elevation view of a stud wall with an adjacent stand for supporting a residential water heater, before the installation of drywall. In this view, so that they are visible, the attachment brackets are shown bent outwardly from the studs, which is not their true configuration. 
     FIG. 2 is a diagrammatic horizontal sectional view of the stud wall of FIG. 1 after the installation of drywall showing the water heater anchored to the wall on top of the stand utilizing the system of the present invention. 
     FIG. 3 is an isometric view of one of the brackets of the system of the present invention. 
     FIG. 4 is a greatly enlarged horizontal sectional view showing details of the mounting of a bracket to a stud and the connection of a strap thereto in accordance with the system and method of the present invention. 
     FIG. 5 is a plan view of a segment of one of the straps of the system of the present invention. 
     FIG. 6 is a greatly enlarged horizontal sectional view illustrating the manner in which a bolt assembly initially connects a strap attachment portion of a bracket to a terminal end of a strap so that it may be subsequently tightened to put tension on the strap. 
     FIG. 7 is a greatly enlarged horizontal sectional view illustrating an alternate configuration for attaching the bracket of FIG. 3 after installation of the drywall. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIGS. 1 and 2, during a framing stage of construction, and prior to the installation of drywall, an upper pair of horizontally spaced brackets 10 and 12 and a lower pair of horizontally spaced brackets 14 and 16 are installed on a plurality of vertical studs 18 and 20 in a stud wall 22 adjacent a location where a water heater 24 is to be anchored. The height of the brackets is selected so that the straps connected thereto will engage the top third and bottom third water of the water heater, as prescribed by the applicable plumbing code. The water heater 24 is a generally cylindrical upright container of the type normally used in residences. It may be gas or electric powered and typically has a capacity of fifty gallons. The location is usually on top of a stand 26 that elevates the water heater off the floor as prescribed by the applicable plumbing code. 
     Each of the brackets 10, 12, 14 and 16 has an identical configuration, and its manner of attachment to its associated stud is identical to the way the other brackets are attached to their corresponding studs. Therefore, only the configuration of bracket 10 and its manner of attachment to the stud 18 need be described in detail. The bracket 10 (FIG. 3) has a generally L-shaped configuration that includes a inner first leg 10a that is secured to the rear side of the stud 18 as illustrated in FIG. 4. The leg 10a is preferably secured to the stud 18 with at least one fastener, such as a sixteen penny nail 28 (FIG. 4). The bracket 10 further has a second leg 10b that forms a strap attachment portion. The strap attachment portion 10b (FIG. 3) extends perpendicularly in an outward direction from the stud 18. 
     Conventional drywall 30 (FIG. 4) is installed over the plurality of studs in a manner that allows the strap attachment portion 10b of the bracket 10 to penetrate through the drywall 30. The strap attachment portion 10b has an outer end 10c (FIG. 3) with a tapered shape that facilitates penetration through a sheet of drywall manually forced against the same by an installer, much like a knife blade penetrating through a cardboard sheet. During taping and mudding, the areas around the base of each strap attachment portion can be finished off for aesthetic reasons, prior to painting. 
     Next the water heater 24 (FIG. 2) is vertically positioned at the installation location on top of the stand 26 between the upper brackets 10 and 12 and lower brackets 14 and 16. An upper strap 32 (FIG. 2) and a lower strap (not illustrated) are cut so that each strap has a length or dimension that allows it to partially encircle the water heater 24. At the same time, the upper and lower straps are cut to length so that a pair of terminal ends of each strap can reach the strap attachment portions of the corresponding brackets. Finally, one terminal end of the upper strap 32 is secured to the strap attachment portion 10b of the upper bracket 10 via nut and bolt assembly 34 (FIG. 4). The other terminal end of the upper strap 32 is similarly secured to the strap attachment portion of the upper bracket 12. The lower strap (not illustrated) is similarly connected to the lower brackets 14 and 16. 
     The bracket 10 (FIG. 3) is preferably made of a unitary piece of sheet metal such as fourteen gauge steel. The inner first leg 10a has a length which is substantially the same as the thickness (smaller dimension) of the stud 18. This facilitates attachment of the first leg 10a to the rear side of the stud 18. The second leg 10b of the bracket 10 has a length substantially greater than the width (large dimension) of the stud 18. This allows the second leg 10b to extend across the stud in an outward direction and through the drywall 30 to form a projecting strap attachment portion, as best seen in FIG. 4. The inner first leg 10a has a first elongated aperture 36 (FIG. 3) and a first plurality of round fastener holes 38 and 40 formed therein. The second leg or strap attachment portion 10b has a second elongated aperture 42, a second plurality of round fastener holes 44 and 46, and a larger round hole 47 formed therein. The elongated apertures 36 and 42 each have a diameter suitable for having the bolt 34a of an assembly 34 (FIG. 4) inserted therethrough. The reason for the elongation of the apertures 36 and 42 will be explained hereafter. Suitable fasteners such as nails or screws of the proper size and length may be hammered or screwed into the fastener holes. Two sixteen penny nails 28 driven through the holes 38 and 44 into two adjacent sides of the stud 18 has proven more than sufficient to securely anchor the bracket to the stud wall 22. 
     Both the upper and lower straps are identical so only the upper strap 32 need be described. FIG. 5 is a plan view of a segment of the strap 32. As previously mentioned, it is dimensioned for partially encircling the water heater 24 as shown in FIG. 2. The strap 32 is preferably made of sheet metal such as twenty-two gauge steel. It has a plurality of equally spaced identical holes 48 punched along the length thereof with a diameter suitable for having the bolt 34a of an assembly 34 (FIG. 4) inserted therethrough. 
     Each nut and bolt assembly 34 (FIG. 4) provides a means for connecting a terminal end of a corresponding strap to a bracket. More particularly, as illustrated in FIG. 4, the threaded shank of the bolt 34a extends through the elongated aperture 42 of the strap attachment portion 10b of the bracket 10, and through the final or last hole 48 at one end of the strap 32. A washer 50 is positioned between the head of the bolt 34a aid the strap 32. A nut 34b is screwed over the threaded shank of the bolt 34a down tight against the strap attachment portion 10b of the bracket 10. 
     FIG. 6 is a sectional view illustrating the manner in which the bolt assembly 34 initially connects the strap attachment portion 10b of the bracket 10 to the terminal end of the strap 32. When installing the system of the present invention, the plumber measures the distance between the brackets 10 and 12, for example from the hole 42 in one bracket to the hole 42 in the other bracket. The plumber then cuts a piece of strap 32 slightly less (to the nearest hole 48) than the measurement that was taken. Two bolt assemblies 34 are then used to connect the terminal ends of the strap 32 (through the final hole in each end of the strap) to the strap attachment portions of the brackets. The strap is slightly shorter than the measured distance and the holes 42 in the two brackets are elongated to allow for variations in tolerances. Because of this, each bolt 34a initially extends at an angle as illustrated in FIG. 6. Thereafter, each nut 34b may be tightened to put tension on the strap 32 and pull it snug against the periphery of the water heater 24. The direction of pulling is indicated by the arrow in FIG. 6. 
     FIG. 2 shows that there is no space between the strap 32 and the water heater 24 after tightening the strap 32. Zero clearance water heaters should press against the drywall 30 when the upper and lower straps are tensioned. Other water heaters should have extra blocks of drywall or other suitable non-combustible spacers (not illustrated) between the water heater 24 and the drywall 30 overlying the stud wall 22. 
     Rigorous tests of a prototype of the system described above were conducted by an independent testing agency approved by the State Architect of the State of California. It was found to far exceed the safety requirements imposed by the above referenced California Health and Safety Code section, thereby legally entitling it to be called an &#34;ACCEPTABLE METHOD&#34; for anchoring water heaters in the State of California. Unlike the prior art approaches described in the background above, the strength of the attachment between the straps of my invention and the studs does not rely on the tensile strength or pull out force of a lag bolt. With the prior art approaches, if a pilot hole is drilled too large or if the studs are partially missed, the lag bolt may not have the required degree of tensile strength. 
     With my invention, a kit can be supplied to the builder consisting of a single roll of strap 32 along with numerous brackets 10 and 12 and nut and bolt assemblies 34. The upper and lower strap segments can be cut to length from the roll, with no waste. Prior art designs, such as the SPACEMAKER TS-E-25 and the HoldRite products described above, require extra length straps in order to accommodate any size and installation demands. This is partly necessitated due to their utilization of buckle-type strap segment connectors. With the aforementioned commercial products significant strap is cut away and discarded and ends up rusting in landfills. 
     In some cases the builder may forget to instruct the plumber to install the brackets 10, 12, 14 and 16 during the framing stage. FIG. 7 is a diagrammatic view illustrating an alternate configuration for attaching the bracket of FIG. 3 after installation of the drywall. Once the drywall 30 has been installed, the brackets can still be installed in a different configuration over the drywall. However, this method suffers from the same drawbacks attributable to difficulty in locating the studs as described in the background above. Nevertheless, the installation configuration shown in FIG. 7 illustrates the versatility of my invention. Again, only the installation and connection of the bracket 10 need be described since the same discussion applies to the brackets 12, 14 and 16. The second leg 10b of the bracket is placed over the drywall 30. After a pilot hole 52 has been drilled into the stud 18, a lag bolt 54 is inserted through the larger round hole 47 (FIG. 3) in the second leg 10b and is tightened into the pilot hole. Referring again to FIG. 7, the bolt of the assembly 34 is then used to connect the end of the strap 32 to the inner first leg 10a of the bracket 10 using the elongate hole 36 (FIG. 3) in the first leg 10a of the bracket. The nut of the assembly 34 is then tightened to cinch up the strap 32 as explained in connection with FIG. 6. 
     Having described preferred embodiments of my system and method for restraining water heaters from tipping over due to earthquake or wind induced motion, it should be apparent to those skilled in the art that my invention may be modified in both arrangement and detail. For example, where codes permit the same, only one set of brackets and one strap need be utilized. The stud wall could form a corner or a U-shaped pocket and the straps could then be even shorter. The first leg 10a could be eliminated. Also, my invention could be implemented with any fixture or anchoring device attached to the framing members before the installation of any type of wall covering. Therefore the protection afforded my invention should only be limited in accordance with the scope of the following claims.