Gutters along the length of the lanai helped my rain problem. But....if the wind blows into it, the lanai will get wet.

If rain is coming in the bottom what is preventing it from coming in the top. Unless you enclose it you will have water

We ended up putting gutters around ours. That did help a little. Some people put down rock bed to reduce the splashing back into the lanai. Also, screen drains are inexpensive - to allow the water to drain from the lanai.

Funny post right here!

Have you been to one of the Big Box hardware stores to ask for a Patio Rain Lock?

Just wondering here. Is the issue that rain is coming into your lanai and not properly draining out? If so, there's a solution for that. Screen Room Drains - Screen Room Drains

A screened lanai will always let water in. There is going to be wind with storms and the rain will be horizontal from the bottom of the screen all the way to the top, gutters won’t help. You will have to make it water tight between each aluminum post or it will leak.
The cheapest thing you can do is put weeping holes in the corners so any rain you get in your lanai will drain out or you will get a lot of standing water

Florida Glass
 

Remove the screen on the lower section replace it with Florida Glass, a translucent vinyl. It is installed easily by using the same spline that holds the screening in. It is sold in 36" rolls, cuts with a scissors and prevents dirt, rain grass clippings etc from entering the lanai.

Do you have gutters in place

Rain coming into lanai
 

I had screening that is called Florida glass installed along the bottom of my bird cage. This looks like screening but is backed with plastic. Rain still coms in from the top sometimes but the dirt that was splashed in from the rain on the bottom is no longer a problem. Any screen installer can help you.

Reconsider
 

I would enclose the Lanai with sliding patio doors from a licensed vendor. It’s pricey, but you will have years of hassle free comfort and increase the value of your home.

Lived in TV 15 plus years and living in Florida with wind/rain the only way to REALLY keep the rain out is to enclose it! It’s a screened porch. Otherwise, let er’ rain!

You got rain? Quit yer bragging and just move the furniture!

Is the rain blowing in at a angle, or is it running in under the screen frame, We put a bead of chalking around the bottom of the frame & it stopped most of the water, but we actually had some rain when it rained hard blow in at different heights. It’s hard to tell whether to cover it at just the bottom or just a foot up from bottom, half way up or cover the whole thing. Probably the best thing to do is get a roll up that they sell that you can cover the Lanai just when it rains. Otherwise it’s just guessing what to do. Sorry I wasn’t much help but didn’t want to guess!

Slit up some plastic Compost bags, and tack them round lanai.
Break up a couple of pallets, and secure the plastic by nailing them to the uprights every foot all way round.
Works a treat, and very cheap.:shrug: