No, The insulation mustn't touch the drywall. Insulation is intended to manage temperature; if it touches the drywall, it is going to take in humidity with the air, which may result in mold and mildew expansion. To cure this and prevent dampness difficulties, wrap the plumbing with foam pipe sleeves. https://israel9jszh.smblogsites.com/32258817/the-fact-about-insulation-installation-that-no-one-is-suggesting