>> > "skroob"> wrote
>> >>> Why do they make them so heavy?
>> >> Its a factor of volume and the atomic weights of the elements that
>> >> the components of concrete. I dont think they have much choice in
>> >> matter. ;)
>> > Someone told me that the builders fill the hollow portions of the
>> > with concrete after they have been stacked in the shape of a wall.
>> > If the blocks are going to be filled with concrete anyway, why can't
>> they be
>> > made of a less heavy substance?
>> > Seems like it would be easier and faster to build walls if the
>> > lighter than they presently are.
>> > There must be a flaw in my thinking, otherwise someone would have
>> thought of
>> > this already.
>> Don? you need to get out more LOL
>> CMU do not need to be filled with concrete when the wall is built,
>> however they can be at times.
>> Sometime we add rebar and grout solid to give additional strength at
>> certain vertical elements, sometimes horizonatal courses are grouted
>> (bond beams) some times just a small area is grouts solid.....around
>> lintel bearing. The open cells are often filled with insulation if it
>> only a single wythe wall. Also note that CMU comes in different
>> based on its composition, which can also affect it's fire rating.
> Since I (and all detailers I know) really dislike detailing masonry fill
> cells, I would be all for the elimination of CMU walls. PIP or Tilt-Up
> panels should be mandatory.
Nope.......we use intergral color ground face more than any other material