Roof Leaking On Underside Plywood

Look for damp spots on the underside of your roof.

Roof leaking on underside plywood.

Trowel the roofing tar into the leak on the underside of the roof deck using a putty knife. Rotted plywood cannot support the weight of a roof the way healthy wood can nor can it safely grip the nails put into the roof and keep them held firm. It also dips along the edge where the moldy plywood exists. Often water runs to openings in the vapor barrier such as at ceiling light fixtures.

Cracking noises can sometimes be heard when walking on the roof during wintertime as a thin layer of ice breaks he adds. Sometimes the water shows up at a ceiling spot distant from the leak. Unless the roof is leaking the line you see on the roof is an aesthetic problem but the cupped plywood is putting an added strain on the shingles either side of the visible line. Also look for a thin stream of water flowing down one of the rafters.

On structural concrete and possibly wood planks or plywood moisture drips may not be observed. If your ceiling has a plastic vapor barrier between the drywall and the attic insulation push the insulation aside and look for flow stains on the plastic. Step 2 shine a flashlight along the underside of the roof and look for a hole in the roof as well as areas that are wet or have been darkened by moisture. Mold on the underside of roof sheathing is also very common.

Push the shingle or plywood into the tar and trowel more roofing tar around the edges of the patch. Rotted plywood can cause a number of issues. The presence of mold in your attic is often the result of poor ventilation insufficient insulation moisture from a roof leak or improper venting from your bathrooms or kitchen. Moisture causes wood to rot and rotten wood absorbs water even more readily than fresh wood.

Roof cuts and thermographic imaging can also detect moisture in addition to other strategies. At the intersection of the plywood overlays the upper sheets contain black mold spreading about 2 3 up the slope. Locate the source of the leak by examining the underside of the roof from within your attic or crawl space. Mold that grows on the underside of roof sheathing due to ideal mold growth conditions being present.