Solid chimney block vs. hollow

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New Member
Aug 17, 2023

I have a masonry chimney with clay flue liner on the interior of my home. It exits through the peak of the roof. The chimney consists of hollow concrete chimney blocks that are 17" x 17" with an 8" x 8" clay liner. Need to rebuild top half of the chimney before installing a flexible chimney liner as many of the concrete blocks were cracked and clay flue is shot. I see that solid chimney blocks are available in the same size. Why would one want to use 17x17 solid blocks vs. the hollow block of the same size? Code Reasons? Thanks
Sorry no idea. Someone like @bgreen would likely know.
Sorry, I'm not a mason. That's a field I know little about. I could speculate as to the benefit of solid block at the top of the chimney for setting the crown, but that's just a guess. bholler has much more experience in chimney work.
I have never heard of solid chimney block but they sound absolutely horrible to me lol. The cored ones are heavy enough