Apparatus for forming a liquid-tight seal across gaps formed between adjacent components of a load-supporting surface useful at an outdoor worksite, the load-supporting surface being capable of supporting the weight of people, vehicles and equipment thereupon, the apparatus comprising: at least first and second mats (26a, 26b) arranged and adapted to be positioned adjacent to one another and releasably interconnected in the load-supporting surface, each said mat being configured to support the weight of people, vehicles and equipment thereupon, each said mat having an upper surface, at least a first side and an outer edge extending at least partially along said first side, wherein when said first side of said first mat is, in use, positioned adjacent to said first side of said second mat and said first and second mats are interconnected in the load-supporting surface, said outer edge of said first side of said first mat faces said outer edge of said first side of said second mat and a gap is formed therebetween; and characterised by comprising: a first liquid impermeable, elongated seal member having a front portion and a rear portion, said rear portion of said first seal member being configured to be coupled to said outer edge of said first side of said first mat, said front portion of said first seal member being configured to extend laterally outwardly therefrom into a portion of said gap when said first side of said first mat is positioned adjacent to said first side of said second mat and said first and second mats are interconnected in the load-supporting surface; and a second liquid impermeable, elongated seal member having a front portion and a rear portion, said rear portion of said second seal member being configured to be coupled to said outer edge of said first side of said second mat, said front portion of said second seal member being configured to extend laterally outwardly therefrom into a portion of said gap when said first side of said first mat is positioned adjacent to said first side of said second mat and said first and second mats are interconnected in the load-supporting surface, wherein when said first side of said first mat is positioned adjacent to said first side of said second mat and said first and second mats are interconnected in the load-supporting surface, said respective front portions of said first and second seal members (118a, 118b) abut one another in said gap to form a liquid tight seal therebetween and prevent the entry of liquid into said gap from said upper surfaces of said first and second mats. a first liquid impermeable, elongated seal member having a front portion and a rear portion, said rear portion of said first seal member being configured to be coupled to said outer edge of said first side of said first mat, said front portion of said first seal member being configured to extend laterally outwardly therefrom into a portion of said gap when said first side of said first mat is positioned adjacent to said first side of said second mat and said first and second mats are interconnected in the load-supporting surface; and a second liquid impermeable, elongated seal member having a front portion and a rear portion, said rear portion of said second seal member being configured to be coupled to said outer edge of said first side of said second mat, said front portion of said second seal member being configured to extend laterally outwardly therefrom into a portion of said gap when said first side of said first mat is positioned adjacent to said first side of said second mat and said first and second mats are interconnected in the load-supporting surface, wherein when said first side of said first mat is positioned adjacent to said first side of said second mat and said first and second mats are interconnected in the load-supporting surface, said respective front portions of said first and second seal members (118a, 118b) abut one another in said gap to form a liquid tight seal therebetween and prevent the entry of liquid into said gap from said upper surfaces of said first and second mats.