Expert: Dan Griffin - 7/17/2008

Question
I am a designer who typicall works on residential and commercail finishouts. Most all of my projects are wood framed. I am designing a 20'x40'incubation center for a wildlife center. The center has some remaining split face cmu block from its previous building that they want to use. They also want to be able to hose down the interior of the incubation part of the building. I had planned on using the 8x8x16 2 core cmu block as the only wall. I am having second thoughts about installing the plumbing vents in the core of the cmu block. All of the plumbing (3 sinks) for this building are located on exterior walls. I had also planned on filling all cores with concrete to improve the r-value of the building. Can I install the plumbing in the hollow cores and what issues or concerns would you have. The building will be built in central texas so i dont think freezing will be and issue. the bldg will have to keep an average temperature of around 68 degrees. Will the cmu wall provide a descent r-value for the home. Any help you can provide is greatly appreciated.

Thanks,

Jason Massey
A & E Drafting and Design

Answer
I asume you are talking about foam filling the CMU.  There are contracors in that business that can tell you what R rating this will yield, costs, and nuber of holes required ot fill around the slushed cores.  Vent lines for sinks, etc will be 1 1/2 or 2s which should present no problem for 8" block cells assuming you can get them back deeper in the roof above ceiling - Same with water.  YOu may develop better R with metal studs, extruded styrene, and FRP.  YOu still don't want roof penetrations at the outside eave.