Table of Contents

How to Install a Roof

Table of Contents

How to Install a Roof. Building or renovating a house is expensive. One way to cut costs is to roof the building yourself. Installing a roof is a long and challenging project, but with the right supplies and guidance, saving thousands of dollars in contractor's fees is a real possibility.

Install a Roof

Order the Trusses

  1. Review the blue prints for the size of the area you are roofing.

  2. Look for a lumber yard or truss company in your area. The truss is basically the frame for your roof. Search the phone book or search online for companies who sell trusses. Ask friends or local, trustworthy contractors who they use for roofing supplies.

  3. Find a company nearby or one who delivers.

  4. Order your trusses. The pieces are made in factories to your specifications. Some lumberyards and supply stores keep standard sizes in stock. When ordering your trusses, tell the salesman the, size of rafters, exact slope, and length of overhang, size of ridge beams and bearing beams, and size and location of ceiling joists.

  5. Drive a nail into the top beams of the house. Set the nails ¾ inch from the end of the building.

  6. Measure 16 inches and mark the board with an "X." Place the "X" on the side closest to the nail. If you have overhangs on either end, adjust the measurement so the plywood reaches from the end of the overhang to the middle of an interior truss.

Frame the Roof

  1. Raise one of the rafter trusses, turn it upside down and lean it against the rafter ties. Place another rafter truss the same way at the opposite end of the building.

  2. Rotate the truss up into position. You may need leverage. If you need leverage nail a board to the truss to help swing it around.

  3. Nail the rafter tie into place over the "X" marks you created. This should be where the rafter connects with the cap plate.

  4. Install a temporary brace to the hold the truss up across the top cord where it slopes. Have someone hold a 4x8 foot board level against each truss while you nail it to the truss.

  5. Repeat these steps until all of the trusses are in place.

Sheathing the Roof

  1. Pop a chalk line at your desired length across the rafter tails that are hanging off the sides. Trim the rafters so all of them are the same length.

  2. Attach the sheets of ply board to the edge of the rafter tails and work Upwards to the top of the roof. Cut any excess plywood off at the ridge of the roof to fit it perfectly onto the center of the rafters.

  3. Make a chalk line to mark the center of the rafters. Nail the nails along the chalk lines according to local building codes. Contact the city or county offices for the building codes.

  4. Stagger the connecting points as you work across the roof. Cut some panels in half and use the half sheets with every other row of sheathing. If more stability is needed, special metal plywood clips are available at hardware and supply stores. Install the clips in the spaces where the plywood meets between the trusses.

  5. Checking the alignment and end supports from the bottom to the top of the roof. Toe boards are often used across the lower ply board.

  6. Cut off any excess overhang with a circular saw.

  7. Repeat these steps on the other slope of the roof.

Applying Tar Paper

  1. Snap horizontal chalk lines across the roof sheathing starting at 35 5/8 inches above the eaves.

  2. Place the paper on the roof lining the paper up with the side edge of the roof. Leave 4 inches of paper to overlap joining pieces and 6 inches to overlap ridges and hips.

  3. Smooth out the tar paper before it is secured to the roof.

  4. Use a staple gun with 1/4-inch staples to secure the tar paper. Staple every 12 inches. Other options besides the staple gun are a pneumatic stapler or a hammer-tacker.

Shingle the Roof

  1. Start the first row of shingles. The starter row for drip edge shingles should be the under the drip edge at the sides, on top of the drip edges and at the eaves. Composite asphalts shingles start at the eave with 3 inches cut off the tab at the ends.

  2. Nail each starter shingle with 4 12-inch galvanized roofing nails. Place them 3 inches above the eave. Allow a 1/2 inch overhang on the eave. A 1/16 inch space should be left between each shingle.

  3. Install the next row of shingles on top of the starter row, with the tabs facing the eave. Attach the remaining rows by nailing 4 nails per shingle. Place the nails 5 5/8 inches above the bottom line, and 1 inch and 12 inches from the edge of the shingle.

  4. Trim first shingle on the second row 6 inches. Cut 12 inches off the third row of shingles. Keep cutting in 6-inch intervals until the seventh row of shingles. On the seventh row, start the cycle over with a full-size shingle.

  5. Attach the hip shingles or ridge shingles. Cable roofs have ridge shingles. Hip roofs have ridge shingles that overlap the hip shingles. These Shingles are purchased already cut for installation. To make hip shingles cut a 12-inch tab of a regular shingle.

  6. Mark each side of the hip or ridge line 6 inches down. This is the guideline for the shingles.

  7. Lay the cut shingles over the ridge. Line up the edge of the shingles with the chalk line. Make sure the shingles are centered over the ridge of the house.

  8. Nail two nails into the shingle right above the sealant tab. cut the shingle up the center of a tab 4 inches where the hip and ridge intersect. Nail the top of the hip to the 4 inch overlap, over the end of the last shingle.

  9. Fold the last shingle over the eave of the roof and place one nail in the fold and two nails on each side of the ridge.

  10. Apply roofing cement on each nail to seal the roof.

  11. Seal the edges of the shingles, nails and bolts for antennas or satellites with roofing cement in a caulking gun.

  12. Tip

    Check local building codes and permit requirements before beginning work. If the sheathing gets wet, let it dry for a couple of days before adding the tar paper. Wear heavy-soled boots and eye and ear protection.


    Make sure your ladder is secure. Tie the top of the ladder to the house. Do not roof when it is raining or snowing. Do not leave excess materials on the roof. If something is not needed, take it down. Debris on a roof can cause slips and falls.

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