Showing 0 products
Frequently Asked Questions
Why extract along a line rather than at points?
It gives rising air the shortest path out.
Point ventilators leave dead air between them.
Air must travel horizontally to reach one.
It does that slowly and reluctantly.
A continuous opening extracts evenly.
Long buildings benefit most.
Why is the ridge the best position?
It is the highest line available.
Stack height is at its maximum there.
Wind over the roof produces suction at the ridge.
That works regardless of wind direction.
No other position offers both.
It is where the driving forces combine.
What separates one product from another?
Weather resistance, almost entirely.
An open ridge is a hole at the most exposed line.
Internal baffles admit air and exclude rain.
That arrangement is where the engineering sits.
Ask for tested resistance, not a description.
Exposed and snowy sites need the evidence.
How is it sized?
By free area per metre run.
Length then gives the total.
It is not selected as a unit size.
Baffles and screens reduce the figure.
Compare published free area between products.
Match it to the required extraction.
Does it need intake to work?
Absolutely, and it is often forgotten.
Air leaving must be replaced at low level.
Without that the ridge extracts very little.
Wall louvres or intake ventilators provide it.
Size intake free area against the ridge.
The two are one system.
Who should install it?
It is a roofing operation as much as ventilation.
Flashing along both sides keeps the building dry.
That detail belongs to the roofing warranty.
Coordinate before anything is cut.
A leaking ridge is expensive to correct.
Get the detail approved in advance.
Can it be closed when not wanted?
Some products offer dampers along the run.
That allows winter closure or fire control.
Actuated versions link to a control system.
Dampers add cost and a maintenance item.
Unexercised dampers seize over years.
Specify them only where genuinely needed.