Pedestrian Bridge Instructions
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Pedestrian Bridge Instructions The following instructions are for standard Pedestrian Bridges. We attempt to cover different methods and parts lists based on the most common bridge configurations. Custom Bridges, with additional Beams will have different parts lists, but the methods of assembly remain the same. Section 1 - Components The Chart below will help you identify the components and the quantity of each. Note that if you have purchased a bridge with a beam wrap, the number of beams and cross braces are the same but the cross braces are different, so assembly is slightly different as well Number of decking boards are based on the length of the Bridge. The Number of Beams and Cross Brace are dependent on the Width (and decking material). See the charts below for the number of components for your bridge. Also in this chart are the number of Posts and railing sections (The Type of Railing you have selected will have no bearing on the number of components since the sections are pre- assembled). There are two numbers in the cross braces section. There are more cross braces when an extra beam is added because of composite decking – the first number is wood decking, and the second is for composite. Number of Decking Number of Cross Braces Boards and Posts Width > 3’ 4’ 5’ 6’ Length Decking Posts Length v Wood/Comp Wood/Comp Wood/Comp Wood/Comp 6’ 15 8 6’ 1 / 2 2 / 3 3 / 4 4 / 5 8’ 20 8 8’ 2 / 4 4 / 6 6 / 8 8 / 10 10’ 25 8 10’ 3 / 6 6 / 9 9 / 12 12 / 15 12’ 29 10 12’ 4 / 8 8 / 12 12 / 16 16 / 20 14’ 34 10 14’ 4 / 8 8 / 12 12 / 16 16 / 20 16’ 38 10 16’ 5 / 10 10 / 15 15 / 20 20 / 25 18’ 43 12 18’ 5 / 10 10 / 15 15 / 20 20 / 25 20’ 47 12 20’ 5 / 10 10 / 15 15 / 20 20 / 25 Number Of Beams Number of Railing Sections Railing Railing Width Wood Decking Composite Decking Length sections Length sections 3’ 2 3 6’ 6 14’ 8 4’ 3 4 8’ 6 16’ 8 5’ 4 5 10’ 6 18’ 10 6’ 5 6 12’ 8 20’ 10 Other Components: Each Bridge – no matter the size, has two 2x4 End Caps and a Hardware Package Section 2 - Ground Preparation Each side of the Beams should set on a flat surface. Each end of the bridge should also be level with the other end of the bridge. Each side of the bridge should be in contact with at least 8” of solid surface. If you are using the bridge for light duty, you could set the beams on level flat ground. To avoid the beams sinking in soft ground, each beam should be supported by patio blocks, bricks, or pressure treated lumber. Each of our bridges are capable of supporting thousands of pounds, but the base that it sets on must also be able to support the weight of the bridge and the traffic that goes across it. For maximum weight capacity a concrete footer or foundation can be poured. The footer should be wide enough so that at least 8” of each beam seat is supported. All the beams need to set on the foundation. If you intend to have a step up onto the bridge, the foundation can be at ground level. For a smooth transition from the ground, path or walkway on to the bridge, you will need to set the footers below grade. Section 3 - Dimension and other Info: This applies to all pedestrian trail bridges, all railing styles, and both wood and maintenance free bridges. Width of bridge has no bearing on these dimensions. A LENGTH (Total (ARCH S (Seat X - end to hip Y Z (Top flat OF BRIDGE Length) camber) cut) (horizontal) (Up slope) section) 6 72 4 12 24 25 24 8 96 4 16 32 33 32 10 120 4 16 32 33 56 12 144 4 16 32 33 80 14 168 4 16 32 33 104 16 192 4 16 32 33 128 All Lengths: B - Height of Beam = 11.25” E - End Cuts = 3 3/4” NOTE: Named bridge length is the length of the beam. Overall length will include the two end boards. Installation Section 4 - Beam, Cross Braces and Decking Board Assembly NOTE: If the area is over an area that might be dangerous, you may want to assemble the beams and cross braces on a level surface and then move to the area. You need to determine this based on the area, and your abilities. Do not assemble the bridge completely and then attempt to move, unless you have a plan, equipment or manpower to move it, since it would be quite heavy. Step 1 - Set the beams in the general area where they will rest. The first step is to create a “box” using the outside beams and end cap boards as shown below. Step 2 - Determine which beams are for the outsides. Most wood bridges, the beams are interchangeable. If you ordered a flat beam, or on some custom bridges, there will be markings from where the posts will go. Make sure the markings are to the outside of the box. If your bridge has a beam wrap, the wrapped side will face out. The end boards are about 3 ½” tall and the width of the bridge (a 4’ wide bridge will have end caps that are 48” long). Be sure that the end boards are flush with the bottom of the beams, and with the outside. If your bridge has a beam wrap, the end board will be flush with the outside of the beam wrap (see insert). The width of the bridge includes the beam wrap. Step 3 - Attach end cap boards with 2 ½” screws. Step 4 - You will next set the interior beams (if any). The number of interior beams can be found using the chart on page one. If you have a composite decking there is an additional beam added for strength. You may have also added extra beams as well. Set the interior beams inside the box, and set so they are aligned with the pilot holes drilled in the end cap boards. DO NOT attach at this time. You will first need to install the cross braces first. The images at the right show the proper placement of interior beams (DO not attach the beams(s) to the end board at this time.) Cross Braces can be one of two types. If your bridge is wood, or there is no beam wrap, the braces will be short pieces of 2x6 Treated Pine. Step 5a - The cross braces should be offset so that you can easily attach by screwing through the beams and into the cross braces. Make sure the tops of the cross braces are flush with the top of the beam along the center flat areas. On the angled ends of the beams, move the braces down so that they are not above the beam. (Using Two 2 1/2” screws on each end of the cross braces – The beams will not be marked, and no pilot holes). You need to put one brace at near the center and about 24” for each end. Evenly space the others (See image below left) Step 5b - If you have a beam wrap, some of the braces will be T shaped. Since you do not want to screw through the beam wrap, the top of the T will be against the outside beams and will attach using Four 2 1/2” screws from the through the Brace and into inside of the beams. (Do Not over tighten or counter sink the screws). Interior cross braces that do not touch the outside beams will be 2x6’s with no T piece. Attach these with 2 1/2” screws through the beams and into the ends of the braces. (below, right) Step 5c for bridges that have all double beams the cross braces will be H shaped attach both sides like below right photo (showing a T brace) Step 6 - Once installing the cross beams is complete, screw through the end cap boards into the ends of the beams. Be sure that the bottoms of the beams are flush with the bottom of the end cap. Attach with two 2 1/2” screws per beam end. Decking boards are either 2x6 Wood boards or composite boards. Assembly is the same for any of the decking options. The length of the decking boards is the same as the named width of the bridge. Step 7 - Position and attach four boards that will align with the point where the flat top part of the beams and the sloped side as shown below. Attach with 2 ½” screws (If you have selected a composite deck, these Weathermatch screws closely match the color of the decking ). Step 8 - Only the ends of the boards have predrilled pilot holes. Attach to the interior beams with two screws over the center of the interior beams. Step 9 - Position boards along the top flat part of the bridge. Because of slight variations of the width of the wooden boards, you should not use a set dimension to try to space the boards. Before attaching any of the boards, position them so that they are spaced equally… They may even be touching with no gaps between them (This is normal for wooden decking since the boards will shrink over time, and create the gap.