Hi, I have large-2 inch-gaps between the slabs in my patio. Chair legs, and feet, are constantly falling into their depths. I am wondering if there is any way to fill them other than wood? I am not a carpenter...I considered sand or pea gravel, or even caulk or the sand mix for pavers... I just don't know because the gaps are so large and my patio is huge! It is roughly 30 feet long and 7 feet wide. Help, I would love to get some use out of my patio without anyone being injured. And, I would like to be able to fix it myself without spending thousands of dollars.