Find the Best Underdeck Company in York County, SC Express Sunrooms is one of the top Underdeck Companies in York County, SC, specializing in custom underdeck systems that turn the space beneath your deck into a dry, functional area. Our team ensures high-quality installation and exceptional service to enhance your outdoor living experience. Contact us at 803-866-1595. Visit: https://www.expresssunrooms.com/under_deck_ceiling_underdecking