Good Morning, 

Thanks for your qestion. 

50% of a trees roots are within the first foot of soil. You did not indicate how large the tree is and how far away it is from your pavers.  If you don't want to compromise your tree, I would not cut the root. A root that is 1-2 inches thick is probably one of the larger roots of your tree. It would make your tree weaker and more susceptible to high winds. 

If you do decide to cut the root, it takes a tree a year or two to react. It might make one side of the tree fail. 

I would suggest you remove the one paver on the root and space out the pavers to accomodate the root. The roots are the lungs of your tree. You could add more wood chip mulch to avoid tripping on the root. 

Please click on the following link : https://extension.umn.edu/planting-and-growing-guides/storm-damage-landscape-trees  This is about keeping your trees healthy to avoid storm damage. 

Good Luck!