Weatherproof a Shed

Sheds are not always as hardy as other buildings against bad weather, so applying some weatherproofing features is a good idea. For new sheds, building it off the ground is the place to start. Waterproof paint for the outside and insulation for the inside of the shed are good ways to keep moisture from soaking into the wood. The roof will take the majority of inclement weather, so attaching roofing felt is one of the most beneficial ways to weatherproof the shed.

Steps

Weatherproofing the Shed's Structure

  1. Build the shed up off of the ground. If you are building a new shed, it is important to build it on supports rather than directly on the ground. Use cinder blocks or other stone shed supports, or use treated wood to build a framework that keeps it off of the ground.[1]
    • Building the shed on supports keeps groundwater from soaking into it.
    • Your options are limited if your shed is already sitting directly on the ground. You could use heavy machinery to lift the shed and then add a support structure under the shed.
    • Most sheds installed by professionals are built up off of the ground.
  2. Paint the outside with waterproof paint. Go to the hardware store and look in the paint aisle or speak to an employee. Choose an exterior paint that is specifically labelled as waterproof. Paint the entire exterior of the shed, including all four sides and the roof.[2]
    • This creates a water-repelling barrier so the water is not absorbed.
    • If you are painting in conjunction with felting the roof, paint the roof in between cleaning the roof and applying the new felt.
  3. Caulk gaps in the shed's main structure. Grab a caulking gun and some all-purpose, exterior caulk. Look carefully for gaps at the corners and edges of the shed. Check the walls and the ceiling for holes or spaces between boards. Fill any gaps that you find with caulk.

Securing the Openings and Insulating the Shed

  1. Check that the doors and windows are sealed. Always close the doors, and check to make sure they fit against the shed tightly so that nothing gets in. If there are windows that open, make sure they are shut tight any time you are away from the shed. Look around doors and windows for gaps that need to be filled.
  2. Apply weatherstripping around windows and doors. If your windows and doors don't already have foam seals around them, add some. Foam weatherstripping usually comes in a roll and is easy to apply around door frames and windows. It creates a seal for gaps between doors and windows and the frame of the building.
  3. Insulate the inside of the shed. Insulation creates a waterproof layer around the inside structure of the shed. Staple insulation to the support studs of the shed, not to the outside paneling. Insulate the roof, as well as the walls.[3]
    • Bubble wrap is a cheap and effective way to insulate a shed, but you can also use standard fiberglass insulation.
    • Stapling insulation to the studs creates a small air pocket between the outer paneling and the insulation, which helps reduce moisture.

Attaching Roof Felt

  1. Measure the area of the roof. Measure the length and width of one side of the roof. Multiply those numbers to get the area of that side. If the shed is a basic A-frame, multiply that number by two to get the total area of the roof. If the roof has an irregular shape, find the area of each part of the roof.[4]
    • You’ll need to set up a ladder so you can reach the roof. You may also want to have someone on another ladder at the other end of the roof to help you.
    • Write the numbers down so you don’t forget them.
  2. Buy shed roofing felt. Go to the local hardware or home improvement store and locate roof felt. Use the roof area numbers that you wrote down when you measured to ensure that you buy enough felt to cover the entire roof.[5]
    • If you have multiple options of roof felt, you’ll have to choose what is in your price range and seems like quality felt.
  3. Remove existing felt or shingles. Climb up the ladder with a scraper of some kind. A scraper on a long pole is most effective. Position the scraper under the old felt or shingles and work it forward and backward so the roof covering comes loose. If the felt is nailed down or glued tight, this can be time consuming.[6]
    • Be sure to dispose of the felt in the garbage once it is all removed.
  4. Clean the surface of the roof and remove nails. Use a claw hammer or another nail removing tool to pull any nails that are crooked or sticking up from the roof. Any nails that are hammered flush with the roof decking can be left in place. Use a wet rag to wipe down the surface if it seems grimy.[1]
    • Be sure to toss the nails into a bucket or trash barrel so they don’t end up in your yard. Loose nails can pop mower tires or end up in someone’s foot if you leave them on the ground.
  5. Paint the roof with waterproof paint or primer. As mentioned above, weatherproof paint or primer adds an extra layer of sealant, even if you're covering the roof with felt. Paint the roof at the same time that you paint the rest of the shed, or paint it separately when you are focused on felting the shed.
  6. Lay the first piece of felt along the bottom edge of the roof. Unroll the felt horizontally along the length of the roof. Be sure to hang the felt about an inch over the edge of the roof so that water will run off.[1]
    • The width of the rolls of felt you bought and the size of the roof will determine how many pieces of felt you need to lay.
  7. Nail the felt down with galvanized clout nails. The exact type of nail you use can vary, but it’s important to use galvanized nails to insure that they don’t rust. Pound nails into the felt as you unroll it so that it stays in place. Nail around the entire perimeter of the felt, putting a nail roughly every 30cm (about every foot).[4]
    • You’ll need to use nails that are at about 20mm (⅘ inch) long to ensure they go through the felt and secure into the roof.
  8. Overlap the second piece over the first piece. When the first piece of felt is nailed in place, unroll the second piece horizontally as before. Make sure that it slightly overlaps the first piece to aid the flow of water. Nail the second piece in place as before.
    • Cover the whole side of the roof in this way. You may only need one or two pieces, depending on the size of the roof and the size of the felt roll. If you only need to use one piece, move to the other side of the roof.
  9. Nail felt to the second side of the roof. Cover the second part of the roof in the same way you covered the first side. Start at the bottom and hang a bit of felt over the edge. Nail the felt in place as you go along. Be sure to overlap each piece on top of the one before it.
  10. Center a final piece of felt over the apex so it overlaps both sides of the roof. When both sides of the roof are felted, lay one final piece on the top point of the roof. You don’t have to use a piece that is the full width of the roll. Cut it down to one foot or so, making sure it covers the crack of the apex and overlaps each side of the roof.[6]
    • Since the felt on the sides of the roof form a crack at the top, it’s important to cover this with a final solid piece.

Things You'll Need

  • Waterproof paint and paint supplies
  • Caulk and caulk gun
  • Foam weatherstripping
  • Insulation (or bubble wrap)
  • Tape measure
  • Roof felt
  • Ladder
  • Scraper
  • Hammer
  • Hot water
  • Bucket
  • Rag
  • Galvanized nails

Sources and Citations

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