Roof beams

[TONY B]

has anyone got any experience with using Kapur for laminated roof beams. The wood comes from Indonesia and has a dry density of 750kg per cubic metre. Strength dry is SD3 compared to douglas fir which is SD5 and weighs 520kg / cube. I recently used strips of Kapur 90x19 for decking and it feels very light and reasonably strong. I was planning to use it to laminate roof beams which span 3300mm and have 600mm overhang each end to cover the side walkaround decks of my project restoration boat. One side of these planks are grooved to create an air gap when they rest on joists but some people think the grooves were for tread. I plan to leave the grooves and let the epoxy fill these little valleys when its mated to the back of the next one. I want to use 4 strips ( total thickness about 76mm) then plane the sides to get width of beam to be about 76 as well. The crown will be shallow - about 120mm rise in centre over the 4300 mm length. The roof will double as a sunning area so it has to with stand people stumbling around. I was thinking of spacing the beams about 600mm apart and covering the roof with about 16mm ply and glass cloth with epoxy sheath. any comments or advice would be greatly appreciated.