Slate Structural Load & Rafter Integrity Tool

Always require a signed report from a structural engineer if you are switching a home from asphalt to slate. This documented evaluation protects you from future claims related to foundation settling or truss failure caused by the massive weight increase.

Slate requires rafters spaced no more than 16 inches on center. If you encounter a home with 24-inch spacing, you must factor in the cost of sistering the rafters to ensure structural integrity—this is a high-margin upsell that ensures a legal, safe installation.

Yes; position the $250 pre-check as a mark of your technical professionalism. It demonstrates you aren't a 'shingle slinger' and that you care about the long-term safety of the client's home, which helps justify a premium project bid.