How to Build a Platform in a Pole Barn

Design

Step 1

Decide on where in the building and how large of a platform area you want to build.

Step 2

Consult span-tables to determine the lumber needed to frame the platform and the size of floor joists needed. The tables will also help you decide the spacing of the floor joists and spans allowed depending on the expected load to be stored in the loft. (Fifty pounds per square foot is a medium load and will support cabinets and storage shelves containing normal home and garden supplies.)

Step 3

Draw up a design plan and purchase the materials.

Construction

Step 1

Install the 6-by-6 upright support posts. The number needed will be determined by the size and placement of the loft. A small loft in the corner of the building may only require one additional support. A loft running the length of the building will require as many uprights because there are poles or beams used in the walls of the original building.

Step 2

Measure to ensure the upright support(s) are positioned exactly. If the floor of the pole barn is concrete, attach the posts to the floor using metal brackets and special concrete screws. If the floor is gravel, use a post hole digger and bore down through the gravel and soil under the gravel to a depth of 3 feet. Insert the post and back-fill.

Step 3

Use a level to mark the existing posts on the wall of the barn and the new posts added to support the platform at the height you want the loft.

Step 4

Install the perimeter frame of the platform to the existing posts of the original barn wall and to the new support posts erected in the room using the marks you made to ensure the framework is level. Nail the framing lumber to the existing poles and newly installed support 6-by-6s by driving four or more 16-penny nails at each location where the frame contacts a post or pole.

Step 5

Mark the locations where the floor joists will attach to the perimeter frame.

Step 6

Use 1 ½ inch nails to attach a metal joist hanger to the perimeter frame at each spot you’ve marked.

Step 7

Cut the floor joists to the correct length.

Step 8

Set each joist upright into a joist hanger on the front and rear of the platform framework and attach the joists to the hangers using 1 ½ inch nails.

Step 9

Lay the plywood flooring on top of the joists and attach the flooring using 8-penny nails. Two edges of each sheet of plywood should have a “tongue”; the opposite edges are grooved. When adding each additional sheet to the floor, make sure the tongue of one sheet slides into the groove of the adjacent sheet to stiffen the floor.

Step 10

Add a staircase to access the loft if there’s space to accommodate one. Otherwise, access the loft using a sturdy portable or built-in ladder.