How to Build a Roof Over a Deck With 2x4s

A deck roof provides shelter from the sun and the rain.

A roof over a deck provides shade on hot days and protects the deck furniture and your guests from getting wet on rainy days. Building a roof over a deck extends the amount of time each year that you can use your deck for entertaining or just relaxing. You can build a roof over a deck with 2-by-4's in less than a week.

Things You'll Need

• Tape measure
• 8 2-by-4 timbers
• Circular saw
• Ruler
• Pencil
• Hacksaw
• Hammer drill
• Screwdriver drill bit
• 3 inch long screws
• 3 1/2 inch thick plywood sheets
• 3/4 inch long screws
• Exterior grade varnish
• Paintbrush
• Shovel
• Cement
• Sand
• Water
• 2 step ladders
• An assistant
• 4 6 inch wide L-brackets

Instructions

1. Measure the height of the deck from the ground with a tape measure and add nine feet to this measurement. Cut four pieces of 2-by-4's to this length using a circular saw. Measure the length and width of the deck. Cut two pieces of 2-by-4's to the deck width and two pieces of 2-by-4 to the deck length.

2. Measure and draw a 1-by-1 inch square on the ends of each 2-inch wide face of the deck length and deck width 2-by-4 pieces using a pencil and ruler. Cut these squares out of the 2-by-4 pieces to leave a 1-by-1-by-4 inch notch in both ends of each piece. Connect the length and width pieces together by the notches to form a rectangle.

3. Countersink two 3-inch long screws through each corner of the rectangle using a hammer drill and screwdriver drill bit. Cut three sheets of 1/2-inch thick plywood to a length equal to one-third of the length of the deck and a width equal to the width of the deck. Screw the three sheets to the top of the rectangle using countersunk 3/4-inch long screws to form the deck roof.

4. Varnish the deck roof and the four remaining 2-by-4 pieces using exterior grade varnish. Allow the varnish time to dry while you dig a 1-foot deep hole at each corner of the deck. Mix a batch of concrete from one part cement, three parts sand and one part water. Plant a 2-by-4 piece in each hole. Fill the holes to ground level with concrete.

5. Wait 48 hours for the concrete to set. Set up two step ladders on the deck, one by a post at the front of the deck and one by a post at the rear of the deck. Lift the deck roof onto the top of the four 2-by-4 posts with the help of an assistant. Screw the deck roof onto to the four posts using 6-inch wide L-brackets.

Tips & Warnings

• Cover the roof with a layer of roofing felt and tar if you live in an area that gets a lot of rain. This will improve the waterproofing you have already added by varnishing the roof and thereby ensure the plywood lasts for many years without degrading.

• When cutting wood, keep your hands clear of the saw blade. This prevents cuts and accidental injury because of the blade slipping or bouncing on a knot in the wood.

References

• Permaculture: How to Build a DIY Decking Cover
• Made Man: How to Build a Deck Roof