October 18, 2021
How To Buy a Metal Building
This is Part 3 of a multi-part series on deciphering the anchor bolt drawings you will receive from Heritage when you order your custom-designed steel building. To catch up with our multi-part series, Part 1 is available here. While it is not likely that you will be pouring your own concrete, a basic understanding of how to read these plans can potentially save you costly and time-consuming mistakes from mis-placed bolts. Please refer your concrete company to this series, or directly to your project consultant, if they have any questions about the plans or bolt placement.
Heritage does not supply anchor bolts. When your building is delivered, you will ideally have your foundation already poured and cured so that erection can begin immediately. Since the bolts are part of the foundation construction, it is the customer’s responsibility to purchase the proper quantity and sizes of bolts. For structural columns, Heritage does not recommend drilling expansion bolts into an already poured foundation; the best way to ensure maximum structural integrity of your steel building is to place the bolts as directed when pouring the concrete. The only anchor bolts that should be drilled in are those for walk door frames.
Note: An anchor bolt plan is not a substitution for a foundation design. It is provided to show the detailed placement and configuration of the bolts on which your columns will rest.
In the drawings you receive, there will be three pages pertaining to anchor bolts. You should provide copies of those pages to your concrete company so they can use them as a map to place the bolts when pouring your foundation.
Part 3 covers page one of the three pages, shown here in its entirety:
Details about each of the three color-coded sections are below. The color coding is here for demonstrative purposes, so that you can see where each highlighted section is located within the page.
As demonstrated in Part 2 of this series, this building has five different bolt configurations for the anchor bolts, labeled as A, B, C, D, and E. A, B, and C are the structural columns. D and E are the overhead door framed openings, and are the same except one is located on a sidewall, and one is located on an endwall.
By looking in the lower-left corner of the image above, you can see it shows the details for Bolt Configuration A. In the upper-left corner, the diameter of the anchor bolt for this configuration – 5/8” – is shown. SW = sidewall, and EW = endwall. The wall lines shown are flush with the inside of the wall panels; depending on which panel profile you select, there will be a slight rib projection. A representation of PBR panel has been placed on the sidewall in the above image to demonstrate how it would project out.
Since this diagram shows both side- and endwalls, the configuration occurs at the corner of the building. The diagram also shows the steel plate that will attach to the anchor bolts is 8” x 7” and that there will be a C-channel column attached to the plate. The column should be anchored with the C-channel facing away from the sidewall, toward the center of the endwall, using two 5/8” anchor bolts.
To measure out the location of where the anchor bolts should be located for Bolt Configuration A, you would start by measuring 8-1.5=6.5” along the endwall from the corner. At that mark, you would then measure in 4” perpendicular to the endwall, which is where the center of the top bolt in the image will be located. Then you would measure 8+1.5=9.5” along the endwall from the corner, and then 4” in perpendicular to the endwall.
For the opposite corner of the building on that same endwall, you would simply reverse the direction from which you begin measuring. Remember to anchor the column with the C-channel facing in the proper direction – away from the nearest sidewall, toward the center of the endwall.
This image shows the details for Bolt Configuration C. The diameter of the anchor bolts for this configuration are 3/4″ and are shown with X’s through them, which is carried through on all three of the anchor bolt plan pages to denote which size bolts are placed in which locations.
This detail says to “See Plan”. The plan is covered in Part 2 of this series, and it shows the layout diagram of the different configurations for this sample building. Bolt Configuration C, as shown on the plan, occurs 6 times – once on each side of the 3 interior framelines of the sample building. As shown by the plan, these columns will be placed every 25 feet.
To measure where the columns will be located, mark every 25 feet on the sidewall. This gives you the location of the center of the plates. Then measure 2” back along the sidewall from the 25’ mark, and in 8.25+3=11.25” perpendicular to the sidewall. This is where the center of the bottom bolt in the image above will be located. Then go in another 4” on that same measure line to mark the center of the top bolt. Repeat this process measuring 2” on the other side of the center line of the plate. Repeat for all 6 plates.
These two examples should give enough instruction so that the other bolt configurations are easily deciphered.