Find the Best Underdeck Company in York County, SC Express Sunrooms is among the leading Underdeck Companies in York County, SC, providing top-quality underdeck systems that create dry, usable space beneath your deck. Our professional team ensures precise installation and lasting durability, transforming your outdoor area into a functional living space. Contact us at 803-866-1595. Visit: https://www.expresssunrooms.com/under_deck_ceiling_underdecking