To all: Looked at a home today that was 4500 sq. ft. and a radon level of 16 pCi/L. It had a balanced HRV system in the house and also had a sub basement area ( about a 1000 sq. ft. – with a concrete floor ) under the basement. So in all reality the home had 4 levels….sub basement, basement, main floor and a upstairs. 2 questions on this one 1. There is no way to get the system piping up through the four floors and the owner does not want the system on the exterior due to the looks. So I came up with the thought of coring through the sub basement floor and taking that pipe up about 7 feet and then going through the sub basement concrete wall which is the back wall of the basement. Kind of hard to explain but the best way to say it is the sub basement is 20 feet wide while the basement is 40 feet wide sitting over the sub basement. This off course makes the basement floor concrete in the front half with floor joist in the back half and a 8 foot concrete divider wall in between the two areas. This is where I would install the jumper port…from the sub basement floor to the concrete divider wall which separates the 2 areas. After this is done I would go up to the basement level and core through the mechanical room floor and install the system piping. From here I could go up vertically into the attic area 2 floors above. So when the system was turned on it would create a negative pressure field under the basement floor which in turn would do the same with the manifold jumper port which in turn would create a negative pressure field under the sub basement floor. The whole question is this…has anybody ever done a job like that before….does it violate any guidelines with the radon system pulling the radon from under one slab and then through a port and then under another slab to the main port in the basement furnace room and then out through the system motor vent above the roof line ? Any safety issues with this ? To me it is just like a manifold port jumper between two separated basement floor areas except I am using the concrete under slab of the basement floor as part of the radon system. 2. Same house but up in the attic. The owner of this home is a mechanical engineer and we got into a detailed discussion about the motor location which in this house would have to be in the attic area. The problem is that the upstairs takes up part of the attic area itself ( the roof is a 12/12 pitch ). With this noted it is also a high quality, high priced home. The insulation on this home is sprayed on insulation foam. The insulation is sprayed directly onto the rafter areas only and there is no wall insulation, no ceiling insulation and no soffit vents. No outside air gets into the house attic…basically a airtight attic with the only thing between the bedroom wall and the attic is ½ sheetrock. That is where the problem is. The owner says ( I explained to him the guidelines ) that if the purpose for the guidelines and the motor being in the attic is for the safety of the occupants then how safe is it if there was a issue and all that is between the motor and his sons bed is ½ sheetrock then the guidelines do not cover this type of situation and we have to do something different. The question is what, we have to follow the guidelines or like stated in a earlier post get hauled into court at a later date over the issue. So is there any flexibility in this type of situation where doing what you know is right is wrong ( according to the guidelines ) ? Like always….. any thoughts are appreciated. Jim Medley Radon Systems 4 U LLC ********** RN PROF (Subscription changes - archives) - http://list.uiowa.edu/scripts/wa.exe?SUBED1=RADONPROFESSIONALS&A=1 ***********