Why Does It Mean That A Roof Should Breathe?

Why is it said that a roof should breathe?   How can you determine if the roof is properly ventilated?

When roofing contractors say a roof should breathe, they are usually referring to the ventilation system beneath the roof deck.

Most shingle warranties require a lot of ventilation—as much as one square foot of net free ventilation area for each 150 square feet of floor space to be vented or one square foot per 300 square feet when both ridge and soffit ventilators are used.

An effective ventilation system will help:

• Reduce attic heat buildup

• Reduce attic moisture and condensation

• Prevent weather infiltration, i.e., drifting snow, wind-driven rain

• Prevent ice dam build-up (See  ice dam discussion)  Even if you feel you have had satisfactory ventilation performance with your old roof for as long as 20 years, it might be necessary to add ventilation with your new roof to meet the standards mentioned previously.

Why is it said that a roof should breathe?   How can you determine if the roof is properly ventilated?

When contractors say a roof should breathe, they are usually referring to the ventilation system beneath the roof deck.

Most shingle warranties require a lot of ventilation—as much as one square foot of net free ventilation area for each 150 square feet of floor space to be vented or one square foot per 300 square feet when both ridge and soffit ventilators are used.

An effective ventilation system will help:

• Reduce attic heat buildup

• Reduce attic moisture and condensation

• Prevent weather infiltration, i.e., drifting snow, wind-driven rain

• Prevent ice dam build-up (See the following question for ice dam discussion.)  Even if you feel you have had satisfactory ventilation performance with your old roof for as long as 20 years, it might be necessary to add ventilation with your new roof to meet the standards mentioned previously.

Advertisements

Tags: ,

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s


%d bloggers like this: