Ask This Old House general contractor Tom Silva demonstrates the amazing versatility of the humble rafter square. SUBSCRIBE to This Old House: http://bit.ly/SubscribeThisOldHouse Shopping List for How to Use a Speed Square: - PVC baluster [https://amzn.to/2XESZXU], used to make Speed Square holder - 3/4-inch plywood strip [https://amzn.to/31lwFoJ], for reinforcing PVC baluster - Short screws [https://amzn.to/2MHO7R3]…