I'm looking for the water pressure drop across a backflow preventer on a 3/4" to a city main with delivered pressure of about 75 psi. Can anyone stear me to that information?
We have an existing wood framed vaulted ceiling roof that is poorly insulated. We are going to install new rigid insulation, R-38 to bring it to current codes, above the original roof sheathing and cap that with a new layer of OSB. We plan to fasten through the new construction into the...