Installing the right number of roof tile vents is important to ensure adequate roof ventilation and promote air circulation through the roof space.
At Beddoes Products, we specialise in the design and manufacture of roof tile vents, and one of the most common questions we get asked is 'How many tile vents do you need on a roof?'. So, we put together this simple guide to help you calculate how many roof vent tiles you will need.
Total Airflow Required
Before determining how many tile vents you need for your roof, you first need to calculate the total airflow required. You can calculate the total airflow required by completing the following calculation:
Roof Length (mm) x Continuous Airflow Required (mm) = Total Airflow Required
To complete this equation, you will need to know your Roof Length in millimetres (mm). You can calculate this by measuring your roof length in metres and multiplying it by 1,000. For example, a roof that is 10 Metres. You will multiply 10 by 1,000 to get 10,000 Millimetres.
The 'Continuous Airflow Required' is dependent on the pitch of your roof. For roofs with a pitch over 15 degrees, as most tiled roofs are, the 'Continuous Airflow Required' is 10 Millimeters.
Using the example figures above, here is what the equation will look like:
10,000 (Roof Length) x 10 (Continuous Airflow Required) = 100,000 (Total Airflow Required)
Total Airflow Required Calculator
To make it as easy as possible to calculate the required airflow for your roof space, we have created the calculator below. Simply enter the length of your roof in meters, then click the button.
Your Total Airflow Required:
Calculate The Number Of Vents For Your Roof
Now that we know the 'Total Airflow Required' for our roof, we can calculate how many roof tile vents we need for effective ventilation.
The important thing to note at this point is that the number of vents you will need is dependent on the type and design of the roof vent tile you are using. At Beddoes Products, our Roof Tile Vents vary in their 'Ventilation Capacity'.
To make it easy for you, all roof tile vents have their Ventilation Capacity clearly stated in their product descriptions. This allows you to easily calculate how many roof tile vents you need before placing an order with us using the equation below.
Total Airflow Required ÷ Tile Ventilation Capacity = Number of Vents Required
To complete this equation, all you need to do is use the figure we calculated for the 'Total Airflow Required' above and divide it by the 'Tile Ventilation Capacity' from the product description or technical data sheet. To provide you with an idea of the size of this figure, below is a table of some of our most popular roof tile vents and their 'Tile Ventilation Capacity'.
Roof Tile Vent |
Ventilation Capacity |
| Plain Tile Vent | 7,500mm² |
| Marley Ludlow Plus Vent | 7,500mm² |
| Redland 49 Vent | 7,500mm² |
| Rosemary Roof Vent | 7,500mm² |
| Slate Vent | 10,000mm² |
| All Other Roof Tile Vents | 10,000mm² |
Now that you know your 'Tile Ventilation Capacity', we can calculate the total number of roof vents required.
Number of Vents Required:
How To Calculate Roof Tile Vent Spacing?
The final calculation we need to make is the distance required between each roof vent. This may seem obvious, but for effective roof ventilation, the roof tile vents must be evenly spaced across the roof to maximise air circulation.
This last equation is fairly simple, as you can see below:
Roof Length (mm) ÷ Number of Vents = Distance Between Vents
Calculate Roof Tile Vent Spacing
Using the Roof Length (mm) from our first calculation and the Number of Vents values from the previous equation, you can use the calculator below to determine the required spacing between roof vents.
Roof Tile Spacing:
Disclaimer
At Beddoes Products, we are specialists in roof ventilation and roof tile vents. Our experts create guides like these to help provide information and improve your knowledge of roof ventilation.
It is important to note that the content in this guide is for informational purposes only. We regularly check it for accuracy. However, we highly recommend that you seek professional advice and assistance from a qualified roofer or builder.
Beddoes Products will not accept liability for injury, loss or damage from the use of this content.
For more information about roof ventilation, try our Roof Ventilation Guide