How Much Ventilation Does A Roof Need

Many people falsely assume that their roof doesn t require ventilation.

How much ventilation does a roof need. Let owens corning roofing help you calculate exactly how much ventilation you will need for a healthy and balanced attic with our 4 step ventilation calculator. So i ll start by saying something that might sound controversial but really isn t. How much ventilation does a flat roof need. While hardly anybody agrees on the best roof ventilation system everybody agrees some roof vents do hardly any good at all.

However we rarely think like that for roofs even though they undoubtedly require ventilation. Ventilation can be accomplished using various products and techniques. Before we explore how to ventilate an attic space it is prudent to understand how much ventilation is needed. Take for example ridge vents.

A cold roof or hot roof. A vented attic where insulation is placed on an air sealed attic floor is one of the most underappreciated building assemblies that we have in the history of building science. Proper attic ventilation consists of a balance between air intake at your eaves soffits or fascias and air exhaust at or near your roof ridge. Enter square footage calculate or enter the square footage of the attic or area to be vented.

It makes sense as all of us know that the most humid rooms in the house like the bathroom and kitchen need it. Federal housing authority recommends a minimum of at least 1 square foot of attic ventilation evenly split between intake and exhaust for every 300 square feet of attic floor space. The answer depends on the type of roof you have. If the slope of your roof is greater than 6 12 you will need more ventilation to reflect the extra volume of attic space.

How much ventilation does a flat roof need. Hot roofs have the roof deck then insulation then the roofing material. It depends on where the insulation is installed. Calculate 20 per cent more for 7 12 to 10 12 pitches and 30 per cent more for a pitch that is 11 12 or greater.

So much information has been devoted to the subject of roof venting that it s easy to become confused and to lose focus. The majority of roofing experts agree that ridge vents are the most effective and cost effective roof vents available. I have roof vents so i have roof ventilation. Any type of roof from tpo to epdm can be either hot or cold.