Put the umbrella in and tighten up the screw? If the size is way off, you could buy the right size of PVC pipe, say 1" and slip it into the sleeve and slip the umbrella inside that.

Exposed Aggregate is pea gravel...but it's in concrete....very common here in Houston. It is very easy for the guys pouring the deck. They just set a PVC pipe in the ground and pour around it. All of the pipes are the perfect size to accommodate the umbrella pole. So I guess you can say they are universal in size. We told the PB we wanted 3 and he said No Biggie. I know they weren't in the contract, but he told me just to tell the deck guys and tell them where I wanted them and so I did......it's so easy for them and probably a minimal cost. I have read on here that some people have paid $20-40 for each one, but I assume your PB would put them in no charge since the other one was forgotten. I would just tell the deck guys and they should add them. It does work best with a concrete based decking as they just pour the cement around the pipe and that is it. I will try to take a pic for you and post it on here later today. Just remember if you place the umb. sleeve in the decking, it needs to be 3 inches from the coping....probably for strength and to protect the coping.....makes sense, but I just can't explain it. Hope this helps....something so simple is something I could not live without.... Pics later...

I'd say rent a core drill

GoofyYno, Do not use a wood pole. The wood tends to gather water and expand making it difficult to remove. Use a plastic or aluminum pole.