I have a 110 yr old home, originally built on wood piers. At some point, my guess is around 1915, the poured a continuous foundation, about 5 feet tall. The wood piers were cut and sit on the foundation wall. Big fat wood blocks, but the concern is they could rot (which they might be).

I am upgrading this and the mason wants to take out those piers and add concrete block to it. It will be two courses. The blocks will be mortared together, but they will be hollow. Is that ok? All the block is above grade and won't get wet. I have to think its a huge upgrade from the wood spaced 1-2 feet apart.