Alex MacDonald More about Alex MacDonald Alex is a member of CSI and is a LEED Green Associate. He is currently a Manager of Strategic Accounts with USG Corporation. Alex has been with USG since 1984. During his career with USG he has been involved in the promotion of demountable wall systems, roofing products and self-leveling underlayments. He helped USG with the succesful launch of the Securock brand of roofing products. Since 2003 he has helped with the successful launch of the Levelrock brand of self-leveling underlayments for the multifamily marketplace. During that time he has given over 175 presentations to architects, contractors, owners and building code officials. He has become an expert in the area of UL fire rated floor/ceiling assemblies. He is also able to assist decision makers facing the issue of meeting Section 1207 of the building code for STC and IIC sound transmission between floors in multifamily construction.