Cedar Roof Problems

Fungal Rot

• Cedar contains natural preservatives that can keep your roof safe from decay for many years. However, over time, rain, snow and other moisture slowly leech the preservatives from cedar roofing materials, so the roof becomes vulnerable to a host of environmental dangers. One of the most serious is fungi, which grows in cracks in the cedar and extracts nutrients from it. As a result, your roof could begin to rot. Once the roof shows signs of rotting, leaks can easily develop. In extreme cases, your roof could collapse.

Moss Growth

• As with fungal rot, moss begins to grow on a cedar roof after moisture has removed its natural preservatives. Moss can cause serious issues for your roof because it contains soil and water that are potentially damaging to the cedar. Over time, moss might also block rainwater and other moisture from draining off the roof, which can weaken the wood and increase the potential for the growth of fungi and algae. Eventually, your roof could develop a leak or have more serious issues.

Fire Risk

• As a wood, cedar burns quickly and easily, so one errant ember can ignite the roof. As a result, you shouldn't install a cedar roof if you live in an area that is prone to wildfires. In fact, some building codes do not permit the use of cedar roofing in new homes. However, cedar shingles and shakes can be treated with fire resistant chemicals that can improve their fire safety rating. They still do not offer the fire resistance of roofing materials such as slate, metal or clay tile, though.

Curling

• Some cedar roofs develop an issue with the shingles' edges curling or cupping, which can expose the roof deck below. In most cases, problems with curling are the result of poor installation. If you are considering installing cedar shingles, hire a qualified roofing contractor and do not attempt the project yourself. Ensure that your roofing contractor installs the cedar shingles with enough space between them that they can expand in humid conditions. The nails must be properly placed along the edge and butt line as well.