wikiHow to Frame a Dormer

Framing a dormer refers to the first and most important step in constructing an upper-level addition to your home. Whether you're expanding a cramped attic into a bedroom, office or playroom, if you have any carpentry experience, you can accomplish this home renovation goal yourself. Here are some steps to guide you as you learn how to frame a dormer.

Steps

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    Schedule your project considering that the roof will be wide open and the work may last an entire day.
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    Create a layout that incorporates the details of the project such as slope, headroom and exterior appearance.
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    Purchase your materials, including wood, windows and any other specialty items.
    • Arrange for delivery of the materials as well as an industrial trash receptacle for the scraps.
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    Acquire a heavy-duty tarp that is large enough to entirely cover the roof. Stretch the tarp out until it overlaps the roof ridge.
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    Affix the tarp to the roof, screwing a 2 by 4 (5.08 by 10.16 cm) over it. Roll the tarp up so you will be prepared in the event of rain.
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    Remove the shingles and the sheathing board from the area of the roof where the dormer will constructed.
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    Mark the inside edges of the dormer's sidewalls in chalk. Saw from the bottom up on both sides.
    • Do not cut the overhang.
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    Remove the sheathing boards.
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    Mark the layout of the dormer walls on the floor of the attic. and verify that the walls will be square with the home's exterior walls.
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    Trace the layout on the underside of the roof using a plumb bob and install nails through the corners.
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    Remove the shingles from this area and mark cut lines between the nails.
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    Open the roof by sawing through these lines.
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    Indicate the cut lines on the old rafters using the layout you've drawn on the floor as a guide.
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    Reinforce the opening by adding rafters to both sides of the roof. Be sure to fasten the rafters in appropriately.
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    Verify that the new rafters align with the sheathing of the roof.
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    Install a 2 by 6 (5.08 by 15.24 cm) header across the opening.
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    Frame the front wall to fit between the new rafters, assuring that its top is level and that the sides are perfectly plumb. Continuously verify that the walls are squared.
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    Finish framing the walls by installing the side walls.
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    Frame the rafters.
    • To establish the ridge point, stretch a string from the peaks of the new trusses, following that line back into the existing roof.
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    Measure and cut a post to temporarily support the ridge.
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    Measure and cut the valley rafters, assuring that they have the proper angles for the slope.
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    Install the valley rafters using a straightedge to assure that they are properly aligned with the tops of the common rafters.
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    Cut the valley jack rafters so that the angles are equal to the common rafters and create a 45-degree bevel on the bottom.
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    Hang the valley jack rafters, nailing them every 24 inches (0.61 M) on center.
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    Use a 2 by 4 (5.08 by 10.16 cm) to temporarily support the 2 by 8 (5.08 by 20.32 cm) ridge board.
    • Make sure you cut the length of the 2 by 4 (5.08 by 10.16 cm) equally to the ridge board's proper height.
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    Create a header from a 2 by 8 (5.08 by 20.32 cm).
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    Cut it to the length of the opening and then use metal joist hangers to attach it to the new rafters.
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    Attach the rafters to the ridge by driving 16d nails through the ridge and into the rafters.
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    Hang the opposite rafter to the rafter using 8d nails and drive 3 nails into each side.
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    Attach the rafter to the wall plate, using 3 8d toenails.
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    Complete your dormer by filling in the walls and installing the roof.

Tips

  • Be sure to get your blueprints approved by your local building inspector and attain the proper permits, if necessary.
  • Consider hiring a professional architect to properly calculate the structural considerations of your dormer.

Warnings

  • Since this is an extremely dangerous project, it is highly recommended that you rent or purchase a Fall Arrest System (FAS). Follow the manufacturer's instructions to assemble these accessories.


Article Info

Categories: Home Improvements and Repairs | Build Design & Remodel Own Home