Lathing Under Metal Roof

Spacing of furring strips for metal roof when installing a metal roof over an existing roof insulate the spaces between the wood strips with rigid insulation to prevent condensation before.

Lathing under metal roof.

To make clear to readers if firring strips battens are used this should be located under the firring strips so the ventilation airspace is right under the metal where condensation is most likely to occur and to keep any roof boot flashing leakage running off over the top of the water barrier from contacting and corroding the underside of the roofing metal like it would if the water barrier were directly under the roofing though that is the case with roofing direct on sheathing without. The usual way to achieve that is to install vertical lathes first then the horizontal ones.