A leaking window can cause serious problems in a garden building, shed or greenhouse. Excess moisture can damage garden supplies such as seeds and tools, or allow the growth of mould and mildew within a building. Fixing a leaking window is an important part of regular garden building maintenance. Fortunately, repairing a window leak is a simple process that doesn't require any special knowledge.
Remove the window and its frame using a hammer and a flat pry bar. Be careful not to crack the wood frame or break the glass. Ensure that the window and frame come out together so you can repair the entire structure.
Use a putty knife to remove all of the old caulk and glazing from around the edges of the window. This allows you to replace it with a new seal, which will prevent future leaks.
Paint the wood frame around the window with a latex paint to create a new seal on the wood itself and help it repel water more easily. Allow the latex paint to dry before continuing.
Apply a new layer of caulk or sealant around the edges of the window to create a fresh seal and stop water from leaking through the frame. Allow the caulk to dry before putting the window back in place.
Reinstall the window and attach it with screws or nails if necessary. Ensure that the window frame sits tight in the wall frame. Seal it with caulk to prevent water from leaking in around the window frame.