Installing a second mailbox for a tenant or business partner without installing another post is a practical solution that saves time and resources. Whether you manage a residential property or want to streamline mail delivery for a home office, understanding how to mount 2 mailboxes on 1 post ensures a clean, organized, and code-compliant installation. This approach requires careful planning regarding box size, post stability, and local postal regulations.
Understanding Postal Regulations and Box Requirements
Before drilling a single hole, it is essential to consult the regulations set by your local postal authority, such as the USPS in the United States. These rules dictate the exact positioning of the delivery slot relative to the curb and the required clearance for mail carrier access. Standardization ensures that your dual-box setup remains functional for the carrier and compliant with service agreements.
You must also evaluate the physical dimensions of the mailboxes. Side-by-side configurations usually work best for dual installations, as they maintain a low profile and standard access height. Stacking mailboxes vertically is often discouraged because it can obstruct the carrier's arm or complicate the sorting of larger parcels. Measuring the width and depth of both the post and the boxes will help you determine the necessary spacing to prevent interference.
Choosing the Right Post and Mounting Hardware
The stability of the post is the backbone of a successful dual-mount system. A standard 4x4 wooden post or a 1-1/4 inch steel conduit provides the necessary rigidity to support the weight of two boxes. If the post is existing, inspect it for rot or rust; a wobbly post will compromise the security of both mailboxes and fail under stress.
To secure two boxes, you will need heavy-duty u-bolts or J-hooks designed for thick-gauge metal or wood. Using standard, small brackets will likely result in sagging over time. It is also wise to invest in lock nuts or security screws to deter theft, especially in high-traffic areas where the boxes are accessible to the public.
Step-by-Step Installation Process
The installation process begins with the strategic placement of the bracket on the post. You must calculate the centerline height, which is often around 42 to 45 inches from the ground, but verify this with local guidelines. Mark the spot for the two mounting holes for each box, ensuring the slots will face the intended direction for easy access.
Hold the first bracket in place and level it meticulously. A sliding level is crucial here because the post might be slightly curved. Once the first set of holes is marked, drill pilot holes to make driving the lag bolts easier and to prevent the wood from splitting. Repeat this process for the second bracket, verifying the distance between the two sets of holes to ensure the boxes do not collide or appear uneven.
Spacing and Alignment Tips
Proper spacing prevents the doors from hitting each other during opening and closing. A gap of at least 2 to 3 inches between the edge of two side-by-side boxes is usually sufficient. To visualize the layout, you can temporarily place the boxes on the ground next to the post to test the configuration before committing to drilling.
Alignment is critical for aesthetics and function. If one box is mounted crooked, it creates a visual imbalance that makes the entire installation look amateurish. Have a helper hold the boxes in place or use a temporary clamp to ensure alignment while you mark the final drill points on the post.
Securing the System and Final Checks
After tightening the hardware, perform a thorough stability test. Apply a firm wobble to the post to check for any movement. If the post shifts, you must pack the hole with concrete or re-secure the lag bolts with additional washers. A stable post ensures that the boxes remain at the correct height and angle for years of use.
Finally, verify that the doors operate smoothly without rubbing against the adjacent box or post. You may need to adjust the hinges or the bracket position slightly to achieve a perfect swing. Once the mechanism flows freely, you can consider the installation complete, providing a reliable and efficient mail delivery point for two distinct addresses.
