For the metal roofing it s a not brainer.
Metal roof over sips.
When the house was built melton sealed the seams between roof panels with tape applied on the bottom of the panels.
Specifying a cold roof or simply over sheathing the roof with an additional layer of osb staggered over the panel joints will eliminate the possibility of shingle ridging.
Make certain to tape seal all panel joints.
Ensure that panel joints are level to one another as variations in panel height can cause deflection in the roofing material.
Sip panels must be air and watertight.
The roof structure is 10 25 sips on a 2 12 pitch and the developers are going with either metal roofing or a torch down system.
Can i install a metal roof directly over top of the sips.
The ridges caused by the expansion of sip roof panels may be an aesthetic blemish but it does not affect the performance of the roofing or the sip roof panels.
The moisture is very obvious at the seams an appears to have leaked through from the inside of the home.
Here are some important considerations.
I would suggest allowing this to vent in some way the metal directly over the sips roof even with ice and water will get extremely hot.
We ll strap it and create an air space but we ve never done a torch down on sips.
Several assemblies that prevent shingle ridging are described in the builder s guide to structural insulated panels sips.