Bought a 16 pack of bio-bricks today for 3.49. threw 2 of them in to get things heated up quickly,and surprise,surprise they do work for that kind of application. I didn`t weight them, but they seem awfully heavy-(so heavy that I let the cashier scan them and moved them myself to my cart) ;-P ya see, I am not always a bad guy! Only guessing , but thinking that 16pk must have weighed 30lbs or more? I think too expensive to burn on a continuous basis,but have to admit they are even better than my western red cedar to get things fired up in a hurry. And they don`t seem to burn away all that too quickly.