A new concept is the double aerator, comprising two vents, for areas where both the concrete deck and the insulation need to be aerated and ventilated. Here a “special” 100mm high vent is placed onto the bare concrete beneath the waterproofing, and beneath the insulation; and another much higher “ideal” aerator is placed on top of the insulation.

This means that the concrete deck gets a great deal more ventilation and a greater amount of water vapour can be drawn out from it. It also controls the risk of vapour getting trapped under, above or in between insulation boards, potentially causing pressure points or movement beneath the waterproofing membrane.

They are manufactured in TPE and will be both bonded in the usual manner – i.e. with the sandwich bonding method between two layers of adhesive / membrane.

See the CAD images here

These two vents are sold as a pack. Installers need to be sure that they purchase both items.
They must also ensure that in addition they select what cap or casing they require – the standard cap or the “Estraer®” aeration cap.

The standard cap is measured so that D1 is the diameter of the cap at the top; D2 is the diameter at the bottom (where is slots onto the pipe) and H is the height of the cap.

The special ESTRAER® cap is measured so that D1 is the diameter of the cap at the bottom (where is slots onto the pipe); D2 is the diameter of the funnels at each side; and H is the overall height of the cap including the funnels.