What I'm Seeing Now


What I'm Seeing Now (9) - New Home Inspection, 6 of 6

This is the last of my posts regarding new construction inspections.  It is the sixth of six things that I am finding often in new construction, pre-drywall inspections.  This list of six certainly does not represent all of what I am finding in new homes, but they are very common.  This is another one of those construction mistakes that may not manifest for some time, but will be a big problem once it does.

It is this - plastic plumbing support!

Much new construction now utilizes CPVC for supply piping and almost all use PVC for drain, waste and vent lines.  Often they are not supported well.  Plastic is not as strong or as firm as copper.  It needs different support. 

  1. CPVC supply tubing is often run horizontally.  That is fine.  But the support used is typically a nail with a rounded, plastic holder surrounding the pipe.  Often they nail it too hard and it cracks.  More often the nail is on the upper side and if that holder cracks and breaks there is no underneath support for the horizontal pipe.  Then it sags.  If it sags near a joint it is vulnerable to breaking.  If it sags too much it is vulnerable too.  This is pressurized water, so small leaks quickly become big breaks which leak furiously.
  2. Plumbing vent stacks which pass through the roof.  They do that to take advantage of atmospheric pressure to encourage gases to leave the house.  This also expels otherwise noxious, toxic gases into higher air.  These are often supported in the attic space with a small nylon or plastic strap.  These can move over time.  Or stretch.  Or break.  When they do the vertical tubing sags, becomes too short or actually passes through the roof and into the attic space.  Sewer gas is then being expelled into the house!  Yummie, I know.  I see it all the time on one-year inspections.  One day I was on the highway and saw a house in the distance that had both plumbing vents missing from the rubber sleeves still on the roof.  They had both sagged back into the house!  I did not have time to go to an exit, make my way to the neighborhood and try to find that house.  I would have if I could have!
  3. Often AC units are in the attic space.  They are sitting above drain pans.  In proper construction there are two condensate drain lines - the one tied directly into the unit (primary) and another tied to the drain pan (auxiliary).  This tubing tied to the drain pan is of great interest.  It works off of gravity and typically drains out the side or rear of the house.  If you see it dripping, it means that the primary line has clogged and needs cleaning.  BUT, it should incline gently and consistently to that exterior drain.  Often it is not inclined or sags dramatically from lack of support.  In that case, gravity cannot take over, the pan fills with water and the water leaks into the house.  An upper-level AC unit can remove 8 - 10 gallons of water a day from the air.  That water represents a huge leak into your ceiling and does a lot of damage.

All of these things are easily seen on a pre-drywall inspection.  They are often hidden after and hard, if not impossible, to detect.

My recommendation -   always suggest to your clients a pre-drywall inspection when the opportunity presents itself.  Done properly, the money spent is valuable money spent, especially in the long run.

Jay Markanich Real Estate Inspections, LLC  

Based in Bristow, serving all of Northern Virginia.

Office (703) 330-6388   Cell (703) 585-7560


Comment balloon 3 commentsJay Markanich • November 04 2008 02:41AM



Good points to cover, and great post. In my area most of the builders use a float switch instead of the 2nd drain line. it shuts the unit off if water starts filling up the pan.

Posted by Jack Feldmann (Clayton Inspection Service, Inc.) about 12 years ago

Very good information to be aware of.  I showed a house a few weeks ago that had a disconnected gas vent line, so it was exiting in the attic space.  Thanks

Posted by Jim Curry (Long & Foster) about 12 years ago

Jack - In my area too.  Those float switches must be installed properly.  When the AC is running and I test the float switch, about half the time it does not work.  I trust gravity, when the drain line is inclined right!

Jim - you bet!

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) about 12 years ago

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