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How to Add a Room to a Double-Wide

A double-wide trailer provides ready living quarters, but the time may come when you want more room. It is possible to build a room addition to an existing double-wide. It is best to take advantage of a pre-existing exterior door for this extension instead of trying to attempt demolition of the double-wide itself to allow expansion. The integrity of a double-wide is not comparable to a stick-built house. However, using one of the double-wide's doors as a means of passing into a new room is feasible. The results can be dramatic and wholly satisfying.

Things You'll Need

  • Post hole diggers
  • 4-inch-by-4-inch beams
  • 2-inch-by-4-inch studs
  • Quick-drying concrete
  • Ply board
  • Exterior siding
  • Insulation
  • Roof paper
  • Shingles
  • Hammer
  • Nails
  • Power drill
  • Power saw
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Instructions

    • 1

      Dig post holes that are approximately 48 inches apart to serve as the main support for the addition's foundation. These holes should be about 36 inches deep and be well cleared out so that you can set verticals posts without much difficulty.

    • 2

      Place the 4-by-4 beams as your vertical posts in the post holes. Make sure someone holds them perfectly upright while you pour in the quick-drying concrete around the base. When the post is completely set, move on to the next post until all are solidly in place.

    • 3

      Nail in 2-by-4 cross pieces to form the outer frame of the flooring system, making sure they are placed at a level that will meet up well with the height of the doorway leading into the double-wide. Nail in more cross pieces running from one side of the outer frame to the other to form the essential floor system.

    • 4

      Place ply board on top of the floor system and nail it in place to form the decking. This will complete the flooring in its rough state and provide a base on which to build the wall system.

    • 5

      Erect 2-by-4 studs vertically to achieve the desired height for the walls. These studs should be placed approximately 36 inches apart and extend no more than 9 feet. Cap this wall system by nailing a horizontal 2-by-4 across the studs, creating a top outer frame similar to the outer frame of the flooring system.

    • 6

      Build a flat roof by laying down joists in 36-inch intervals. Once they are in place, attach ply board that will form the ceiling.

    • 7

      Nail the ply board in place. Follow this by laying down roofing paper on the exterior and nailing it in place with roofing nails. These nailing points should be about 12 inches apart.

    • 8

      Place the shingles on top of the roofing paper and nail them in place with roofing nails.

    • 9

      Attach desired siding to the exterior walls of the room. Clapboard and vinyl are two popular choices.

    • 10

      Place insulation in the interior of the room's walls to enhance the area's ability to weather cold months with greater efficiency.

    • 11

      Nail ply board over the insulation to create interior walls. These can be painted or can be followed up with a more finished-looking interior wall choice.