Roofs. Every home needs one, yet it is not uncommon for homeowners to pay little to no attention to them. At least until they leak. Inspecting the roof gives you an idea about its age and the condition. ASHI Standards note that inspectors shall inspect the roofing materials, drainage systems, flashing, skylights, chimneys, and roof penetrations as well as describe roofing materials and how the roof was inspected during the house inspection. Antennae, interiors of vent systems, flues, and chimneys that are not readily accessible, as well as other installed accessories, are typically not inspected.

Walking the roof is usually the best means for inspectors, however, in some instances (heavy rain, snow, steepness, or sagging structures) other tools may be required. Drone technology minimizes and helps inspectors get up-close view of the roofing systems.

When your roof is suffering, it’s definitely worth it to repair it or get a new one. Roof damage can cause long-term damage to the home that can be very costly. Know the basic facts and look for signs that your roof may need some attention, and then don’t put repairs off until the problem is too great to be ignored.

Roofs – The Basic Facts

All roofs have five basic components:

1. Sheathing – The boards or sheet material which are fastened to the roof rafters to cover the house.
2. Roof Covering – The shingles, tiles, or sheets which are used to protect the sheathing from the weather.
3. Roof Structure – The rafters and trusses constructed to support the sheathing.
4. Drainage – The features of the roof’s design, such a shape, slope, layout, which affect the ability to shed water.
5. Flashing – The sheet metal or other material laid into the various joints and valleys of the roof to prevent water seepage.

Roof Styles

Roofs perform the same functions but in various styles. Some homes use even more than one style. Here are a few definitions:

1. Shed – (mono-pitched)- A roof with one slope, historically attached to a taller wall.
2. Hip – All sides slope downwards to the walls, usually with a fairly gentle slope
3. Gable – (most common shape)- It consists of two roof sections sloping in opposite directions and placed such that the highest, horizontal edges meet to form the roof ridge.
4. Gambrel – Usually a symmetrical two-sided roof with two slopes on each side.
5. Mansard (Bonnet)- A roof with the lower portion at a lower pitch than the upper portion.

Steepness Or Incline

Another important aspect of roofing structure is the extent of a roofs steepness or incline. This is also referred to as its slope, pitch or angle. The steepness or incline determines the type of roofing material that may or may not be used. A roof with little or no slope is called a low slope or flat roof. These are often bituminous material (asphalt) and gravel (built-up roofs).

Roofing Stats

The type of roof you have depends on what was most popular in practical when and where the home was built. This chart provided by ASHI (The American Society of Home Inspectors) will help you identify the type of roof you have and evaluate its remaining life span and care.

ROOF TYPE	LIFE EXPECTANCY	REMARKS
Asphalt Shingles	15-20 years	Used on nearly 80% of all residential roofs, low maintenance.  *Not recommended for use on low slopes roofs.
Asphalt Multi-Thickness Shingles	20-30 years	Heavier and more durable than regular asphalt shingles.
Asphalt Interlocking Shingles	15-25 years	Especially good in high wind areas.
Asphalt Rolls	10 years	Used on low slope roofs
Built-up Rolls	10-20 years	Used on low slope roofs; 2-3 times as costly as asphalt shingles
Wood Shingles	10-40 years *depending on local conditions and proper installation	Treat with preservative every 5 years to prevent decay.
Clay tiles	20+ years	Durable, fireproof, but not watertight, requiring a good subsurface base.
Cement Tiles	20+ years	Durable, fireproof, but not watertight, requiring a good subsurface base.
Slate Shingles	30-100 years	Extremely durable, but brittle and expensive
Asbestos Cement Shingles	30-75 years	Durable, but brittle and difficult to repair
Metal Roofing	15-40+ years	Comes in sheets and shingles; should be well grounded for protection from lightning; certain metals must be painted

For more information on roof inspections, please contact Dana Mirowski, Owner of Mirowski Inspections located in Springfield Missouri. Mirowski Inspections is an ASHI Certified Home, Commercial, and Infrared Inspection company that is FAA certified for Drone use on both roof inspections and real estate listing video productions.