How to Make a Rain Diverter

Making a Rain Diverter

Installing a rain diverter over the doorway to your house will make life a little easier the next time you come home during a downpour. While diverters are available at many building supply stores, they are not hard to make if you have trouble finding them.

Materials Needed

  • Sheet aluminum
  • Two straight 2x4s
  • Two 3” or larger clamps
  • Rubber mallet
  • Utility knife
  • Straight edge

Sheet aluminum is sold by the roll in the roofing section of building supply stores. You will need a piece 8” wide and two feet longer than the width of the door you plan to cover. While sheet aluminum can be cut with tin snips or even scissors, you can get a smoother more accurate cut using a utility knife and a straight edge such as a framing square.

Lay the aluminum sheet on a flat surface and cut it to length by scoring along the straight edge several times with a utility knife. Bend the aluminum back and forth along the mark until it breaks. Cut the sheet lengthwise to 8” wide using the same method.

Cutting aluminum.

Sandwich the sheet of aluminum between the 2x4s, leaving 2” protruding, and clamp it in place. The edges of the 2x4s must be straight and line up with each other, otherwise the bend will cause wrinkles in the sheet metal.

Clamp the sheet metal.

Start at one end and push down on the protruding aluminum while working toward the other end. Repeat this process several times until the sheet has been bent to a right angle.

Bend the sheet metal.

Using the rubber mallet, or a hammer and block of wood, tap along the edge to finish the bend.

Hammer the sheet metal.

Remove the clamps and attach the diverter to the roof as detailed in the article Installing a Rain Diverter.


  1. have small upper roof on dormer and small shed roof over man and garage doors,and only a two-inch faschia with exposed short rafters on both. gutter would be too big and ruin design, but water from both roofs splashes both doors. How would I install a diverter at the edge of the roof shingles to divert water to either side of the shed? Would this work except for downpours? I’m in Maine.

    • Hi Eggnostriva,
      Premade rain diverters are available at home centers and building supply stores. Since we’ve had a lot of e-mails over the years from viewers that had trouble finding them premade, we decided to demonstrate how to make one yourself, too.

  2. Hi,
    surprised we have not found anything like this here in Australia. I have major water flooding problems front and back patio covers. Our roof is covered in cement tiles so would assume it will still work. How much water will this evacuate-I guess the height of the lip will be a big factor in how much actually gets away and how much flows over the edge.
    Any thoughts much appreciated. Can send photos of the roof (need an email address) if it will make it more understandable.

  3. Why 8-inch wide flashing? Why not 6″? And why not use standard d-style drip edge which comes in a 6-inch width) inverted, as recommended by another website?

    • Russell,
      8″ flashing was used so that after 2″ of it is bent to form the lip, you will have 6″ left to slide under the shingles. Since most shingles have 5″ exposed, that will give 1″ extending under the shingle overlap so that water won’t run under the diverter in the shingle joints.

  4. Is there anyway to hook up a sheet metal rain diverter running about 35 feet across my roof to a downspout. Old house. Roof not level. Can’t use gutters?
    Thank you for any help.

  5. Would like suggestion on using a rain divertor over an external threshold, without damaging the rubber floor. Step out of upstairs room onto balcony floor, which is over a room downstairs. Not much height between threshhold and balcony floor due to it being the ceiling of the downstairs room. Water got in somehow under the door or threshold, on the stationary side, not the side where the French door opens. Ruined laminate planks, somedamage to plywood and lots to ceiling in room below. I keep imaging something similar to an upside down rain gutter, that would sit on the threshold and curve out a few inches to deflect rain and keep snow from piling against the door. I try to keep snow off with leaf blower but can’t shovel snow and then lift over the balcony. I have osteoporosis with healed compression fractures in my thoracic spine plus nerve inpingement in lumbar spine. Item would need to be weight to keep it from blowing back and forth I get strong winds). Can’t nail it into rubber floor. Suggestions greately appreciated. Thank you.

  6. I need to know how to make a rain diverter for a exhaust vent tube with diameter of 18.5 inches that has about a 2 inch tall lip that rests flush against tube all the way around then arches or slantes away from tube about 5 in out and 4 inches down all the way around. I can’t figure out how to measure, mark, and cut my metal. Please help!!!


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