Waterproofing Pergola

Old 06-25-16, 04:54 PM
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Waterproofing Pergola

Hi all,

I'm thinking of installing corrugated polycarbonate panels over my Alumawood pergola for protection before getting some new patio furniture. The only concern I have is that there is no slope. However, I only intend on covering a 10x12 portion of the pergola. Will this coverage area even need a slope? I live in CA where there is no chance of snow and rains maybe a couple weeks a year. I don't want to tackle this project if it's going to require more than slapping on some panels and screwing. I have no experience with this type of thing so I'd rather not try if it's going to require something more complicated.

The panels I'm looking at are the ones from HD found here: Suntuf 26 in. x 12 ft. Polycarbonate Roofing Panel in Clear-101699 - The Home Depot

Any input is much appreciated. Thanks.

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Old 06-26-16, 04:00 AM
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From the installation instructions for the linked product.

This is the amount of height in inches the rafter rises over a 12" run for roofing applications. The minimum recommended slope for Suntuf is 1-1/2" in 12"
Old 06-26-16, 04:49 AM
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Without any slope the corrugated panels will collect dirt and debris and with clear panels all that crud will be visible from below. I would shop for some nice covers for the furniture.
Old 06-27-16, 08:45 AM
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Using furniture covers is what I did originally and found it to be very inconvenient.

There are no trees directly above the pergola and I really wouldn't mind occasionally hosing off the debris if it becomes unsightly. I guess my question really is, would the structure support it when it does rain? If so, are these aluminum beams strong enough for me to walk on (175 lbs.) for installation?
Old 06-27-16, 09:10 AM
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Hard to say from here how much weight the structure will support. I'd be more concerned with water over powering the flashing and rotting out the connected wood than the actual weight of standing water.

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