Hello!

I just bought a house with a composite deck, and I would like to put a large offset/cantilevered umbrella out there. One umbrella I'm considering comes with a huge base, that you fill with 200 lbs of sand. I'd rather mount the stand to the deck using something like this: http://www.amazon.com/Outdoor-Umbrel.../dp/B003R8DEWI. I don't know much about composite decking, and I'm afraid that simply screwing/bolting this stand into my deck will not be strong enough. Does anyone have any information on whether I'm right or worried about nothing?

Thanks!

 

Most composite decking is notoriously soft, since it has lots of plastic in it. And when it gets warm, and/or the steel umbrella bracket heats up, it will get softer yet. A preferable solution might be to mount the bracket on a square, heavy wood member (short 2 x 10 or larger), using counter-bored through-bolts for a flush fit on the bottom. Then mount the wood to the deck by locating its 4 corner holes such that they align with gaps in the deck planks, as it would be a big mistake to drill holes in composite decking. Install a duplicate wood member (having a matching hole pattern) on the underside of the deck, such that your 4 attachment bolts squeeze the composite as they're tightened. Some stain or paint on the wood will help extend its life.