I have some design questions about a pergola 14 foot wide by 12 foot long. I am replacing a pergola attached to my townhouse on two sides. The two sides of the townhouse form an Ã¢ÂÂLÃ¢ÂÂ shape. I want to cover the pergola with polycarbonate sheets.
Because of my community regulations, I canÃ¢ÂÂt expose the cover. So, my idea is to space my 2 x 10 top 24 inches apart and then attach 2 x 2Ã¢ÂÂs inside the beams creating a 4:12 slope. The polycarbonate would be fastened to the 2 x 2Ã¢ÂÂs and supported with a 2 x 2 cross member every 2 feet. I live in Miami Florida and plan to use hail proof polycarbonate.
Similar to the method used to attach the polycarbonate sheeting, I would run another 2 x 2 inside the beams creating 2Ã¢ÂÂ x 2Ã¢ÂÂ boxes that will have bamboo matting stapled to it. Lastly, to create a finished look, I would cover the visible perimeter of the boxes after the bamboo is stapled with 1 x 2Ã¢ÂÂs.
My 14-foot wide beam will be 3 2 x 10Ã¢ÂÂs sandwiched together with adhesive and screws and then attached to the top of my 6 x 6 post with BCS post caps. The 2 x 10Ã¢ÂÂs would have to span 10 feet from the side of the house to the top cross member. The 2 x 10Ã¢ÂÂs would be fastened to the house using joist hangers. They would not be visible from below.
Is my design idea faulty, will the 3 2 x 10Ã¢ÂÂs support the load of the pergola? Do I have enough slope to allow for drainage of rain water? Any ideas are welcome. Thanks