Adding posts for a sun shade sail on existing deck

I'm so sorry for my ignorance and number of questions, but I don't want to ruin my house or deck during this DIY.

Overview: I'm looking to add a sun shade sail to get some shade on my deck. The plan is to attach two posts to my existing deck railing posts. The sail will be attached to those posts on two corners, and the house on the other two. I'm trying to make a setup like this: https://imgur.com/HcC6TFo

First: I think I need to use two 4 x 4's for the posts (like this, right?: https://imgur.com/sJXWzDC). I don't think I can post product links here, so the name of the wood I'm looking at buying is "4 in. x 4 in. x 6 ft. #2 Ground Contact Pressure-Treated Timber." Is this what I need?

Second: What sort of hardware do I need to secure those posts to my existing deck railing posts (the thick ones.. that look pretty much exactly like the wood I just showed you).

Third: What sort of hardware do I need to secure to the house? I imagine I put some sort of screw with a loop on the end into the house, and then use carabiner clips to connect that hardware to the loop on the sun sail. Does that sounds about right? I'm just not sure what the hardware to attach to the house is called.

Ultimately, I just imagine that this sun sail will pick up some force when the wind blows. I live in a valley, and it really blows. So, I want to make sure that whatever I get is strong enough to withstand the wind. I plan to use carabiner clips to take it down when I'm not outside, but I still want to feel safe putting it up.

Thanks for any help you can offer. And, again, please excuse my ignorance. I'm trying to learn, and research has only gotten me so far.

submitted by /u/Ryslin
[link] [comments]

from DIY https://ift.tt/2WWiDIv