Roofing issues are items that come up regularly on home inspection reports.  There is all type of issues that can be found on a home’s roof and I’ll explain the different issues in this article.   I was hired for a home inspection in Schaumburg, Illinois where my client had issues about the roof prior to my start of the inspection.  I try to start a home inspection without any bias to give the seller and the buyer an equal and fair market place for a home inspection.  The roof that I was inspecting was estimated as a 10 years old 3 tab asphalt shingle that seemed to have at least 5 years left in service.  My concerns started when I noticed that there was another layer of roofing shingles under the layer I was inspecting.  I’m not a big fan of multiple layers of shingles on a roof.  The building code throughout most of Illinois is 2 layers of roofing shingles are allowed.  There are a few reasons why I don’t like multiple layers of roofing shingles on a roof.


  • The shear weight of  multiple layers of roofing shingles can cause stress on the framing of a roof and could cause truss’s or rafters to bow and or break. 
  • Multiple layers of roofing shingles can allow hail to cause damage to the shingles.  Hail will hit the shingle with force and the second layer of shingles will allow for a cushion which will cause a hail pot mark on the shingle.  You are less likely to see this hail damage on a roof with single layer of shingles.
  • Adding additional layer of shingles does not allow you to change the flashing, ice shield, felt paper and so on.  These systems do need to be updated.  I’ve inspected homes that had 9 layers of shingles and when removed found that the roof sheathing was totally rotted out from water that was trapped in between the multiple layers.  The Schaumburg home inspection had 2 layers and the 1st layer was installed 39 years ago.  
  • When you have multiple layers of roofing shingles the roof can hold heat and prematurely age.  Removing the 1st layer of shingles generally only costs $500.00 – $1200.00 depending on the size and type of roof you have on your home.
  • If you have a leak in your roof finding the entry point is quite a bit harder when multiple layers of roofing shingles are used.  I found water staining in the attic of the Schaumburg home inspection that I believed came from the flashing on the chimney.  I can not be sure because the chimney flashing went down to the 1st layer of shingles and then was tarred over.  This is a recipe for water intrusion and then mold issues.

As you probably could guess my client from the Schaumburg home inspection was concerned on the replacement costs for a new roof   on his soon to be new home.  I estimated the replacement cost for this home to be $7000.00.  This replacement would be a total tear off and replacement with architectural shingles with a 35 year rating.

As you see there are a lot of questions to ask when looking at a roof.  If you have questions about roofs please contact me at ~ The Thermal Home Inspector or 312-961-4228.

Thanks for stopping by and stay safe.

Jim Kolke