plain clay tile vents

[marlb]

Hi, I am in the middle of a loft conversion and have to provide 5000mm SQ continuous ventilation. I have seen some suitable vents which give 9,000mm SQ each. I am trying to work out how many I need. The roof space is 8.6 m long. Is my math correct? 8.6 x 5000mmSQ = 45.000 mm SQ. So I would need 5 of the vents at 1.8 m Centres. 5 x 9,000 = 45,000 mm SQ.

Or have I got this completely wrong??

 

[^woody^]

How are single tile vents going to provide continuous ventilation between all rafters?

 

[marlb]

The BCO told me that it should be 5mm2 of continuous or similar. The vents are the 'or similar' route..

 

[^woody^]

They might be of similar area, but the concept is to ventilate the whole roof, so have you thought about how air is going to circulate between all the rafters - top to bottom and side to side?

 

[marlb]

There will also be 25,000mm2 in the eaves. This is sorted with eaves vents already..