A frame for recreational vehicles having a pair of oppositely spaced longitudinal frame members, having notches completely therethrough. The longitudinal frame members have a foam core in direct contact with a woven fiber fabric on an exterior of the longitudinal frame members with fabric flaps extending therefrom. The frame has a plurality of transverse stringers having a foam core in direct contact with a woven fiber fabric on an exterior of stringers that rest in notches of the longitudinal members. The stringers are complementary to the notches in the longitudinal members and the stringers have fabric flaps that extend along their length on opposite sides. The stringers extend completely through the longitudinal frame members. The flaps on the longitudinal frame members and the stringers are in overlapping contact. A deck having a layer of fabric covers the stringers, the flaps, and the longitudinal frame members and is impregnated with resin.