How to Build Mobile Home Stairs

Dig holes at the four corners where your new stairs will be located. The holes should be able to accommodate the posts so that the posts can be 3 feet from their neighbors in both directions. Make the holes wide enough to put a 5-gallon bucket's base 3 feet into the ground to get the post below the frost line.

Measure the vertical distance from the bottom of your door to bottom of the holes in the ground. Subtract 1-1/2 inches from this length, and use this as the length of your vertical 4-by-4 posts near the building.

Measure the depth of the two holes that are farthest from the house. Add 7 inches to this height. Cut this length for the lower two 4-by-4 vertical posts.

Pour the concrete powder into the holes and add the amount of water that the manufacturer suggests. Mix it with a shovel (one bag per hole). Move the posts in each hole up and down to loosen any air bubbles. Put the posts into the ground so that they are level and and spaced with their farthest edges 3 feet apart. Drop landscaping rocks around the posts to keep them upright while the concrete cures. Wait the time indicated by the instructions on the bag.

Add the stringers to the posts. Place a stinger on the outside of the right hand post near the door and again at the right hand post away from the door. The jagged edge cut for the risers and treads should be facing up. If it helps, place temporary screws to hold this stringer in place (with one at each end). Drill two holes in each of the posts that the stringer is on so that they are in the center of the posts and 3-inches away from the closest edge of the stringer.

Put a stringer on the other side of the same two posts and use the original holes drilled into the posts as a guide. Pound the carriage bolts through the holes with washers on both of the outer sides. Screw the nuts onto the end of the bolts and tighten them with a channel-lock wrench. Repeat the process on the other stringers and posts. Remove the temporary screws.

Cut 3-foot-wide sections from one 2-by-6 length of pressure treated lumber for the steps. Lay these across the stringers as steps and screw them in with a screw used (between) to keep them the proper width from each other for drainage. Screw the boards into place using the deck screws onto the four stingers at each step. If the step hangs out horizontally over the edge away from the corner, then it is fine.

Cut a pressure-treated 2 by 4 into two 4-foot lengths and one 3-foot length. At the head of the stairs and the lowest step, hold the two 4-foot boards on the side of the stringers. Allow 7 inches to overlap the side of the stinger and the rest to stick straight up. Use the level to make sure the posts are square. Screw these two boards in place.

Place the third board at the top to serve as a rail across the tops of these two 2-by-4 boards. Make sure that the rail is parallel to the lower (straight) edge of the stringer. Use deck screws to attach the rail to the other two 2-by-4 boards. Trim off any extra 2-by-4 board that sticks above the rail.

Use stain, finish and waterproofing for the stairs as you would for any deck.