Roof shingle coverage distances: This article explains what roof shingle exposes and the acceptable amounts. A small amount of shingle exposure can cause cosmetic issues, while excessive exposure can lead to wind damage and shingle blow-off.If you want roof shingle then contact Roofing services.

Definition of shingle exposure

Roof Shingle Exposure is the percentage of a shingle that does not have its upper surface covered by the next shingle course, or in some roofing patterns. It is the percentage of a shingle that does not have an adjacent shingle. The asphalt shingles in our sketch are installed at a 5-inch distance from the red arrows.

Roof Shingle Exposure 

The amount of asphalt shingle (measured in cm or inches) that is left exposed to the weather after successive courses of roofing shingles are placed up the roof slope.

The distance between the lower edge of a roof shingle tab or shingle tab down-slope and the lower edge of a shingle in the row (shingle course) below is called shingle exposure.

 

• 5-inch roof shingle exposure: The average or "standard" asphalt roof exposure amount is either 5" or 5 1/2 inches (metric shingles).

This means that for 12-inch shingle materials, the head lap or covered portion on each shingle course will have a 7" diameter.

 

• 4-inch asphalt roof shingle exposure - For roofs with lower slopes than 4/12, the roofer might use a 4" exposure to improve the roof's resistance to wind-driven rain.

 

• GAF says, This can sometimes be acceptable, but CertainTeed cannot take responsibility for the risks. The appearance of the roof can be affected by a shorter exposure, particularly if there are shadow lines.

 

• 8 1/4 inch asphalt shingle exposure: Shingle exposure can be as low as 8 1/4 inches for some specialty roofing products like GAF-Elk Timberline Prestique Grande40.

Exposure to other Roofing Methods

Other roofing products and methods have different exposure limits. In a BUR roofing system, for example, multiple plies of tarred feel are used to build up the roof. The exposure width is usually defined as the width of each felt ply plus 2".

Nineteen-inch Selvage membrane roofing is also known as Double-Coverage and Split-Sheet roofing. It uses a prepared roofing sheet that has a 17-inch (430mm), granule-surfaced area to be exposed to weather and a 19-inch (485mm) smooth selvage edge.

 

Selvage membrane roofing can also be referred to by the terms SIS, double-coverage, or "Wide Selvate", roofing. (ASTM Standard D371-89 Standard Specification for Asphalt Roll Roofing (Organic Felt) Surfaced With Mineral Granules. Wide Selvage).

Maximum shingle tab exposure amount

Manufacturers recommend a maximum shingle exposure amount. However, a typical asphalt shingle exposure amount for industry-grade shingles would be between 5 and 5 5/8". Some shingle brands allow for greater exposure.

 

GAF/ELK Timberline Grande(r), 40 High Definition(r), asphalt shingles are designed to look like a wood shake roof. This feature allows for an exposure of 8 1/4". It is intended to give more roof coverage per shingle course and reduce roof material costs.

 

Read More:  Installing Architectural Shingles

 

Adjusting the exposure of the shingle tabs near the ridge

Square-tab asphalt roofing shingles are usually installed uniformly on the roof. All courses use the same exposure amount. With this exception, the roofer might adjust the shingle tab coverage 6 courses below the edge so that the final course's shingle tab exposure will be a complete tab. To complete this detail, we may shrink or stretch the exposure amount by about 1/4 inch or less.

Random shingle tab widths & exposures

Other shingle designs or installation patterns may allow the manufacturer or roofer to deliberately change the exposure amount of shingle tabs in a "random tab" shingle pattern. Even though the shingle exposure amount can be varied, there will still be an upper limit or maximum exposure amount.