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Forgotten Flashing

When someone hears the word flashing they automatically think of roof flashing; chimney, DWV, valley, penetration, etc. I have lost count of the times I have seen builders and remodelers omit exterior flashing. Simply put, any exterior penetration or protrusion MUST be flashed. Some installers think that exterior PVC trim does not require flashing because it is impervious to moisture. We will list the exterior areas that should be flashed, how they should be flashed, and what a home inspector should be looking for:

  • Attached decks / balconies, and porches – “Z” flashing on the wall sheathing under the moisture barrier and over the ledger board
  • All window and door rough openings MUST be flashed (remember the EIFS problems).
  • Window and door drip cap flashing should be used on all materials
  • Lower areas of siding (including masonry veneer)
  • Trim – flashing over and below trim
  • Other penetrations like dryer vent, direct vent appliances, HRV intake / exhaust vents, etc.

Of course during a home inspection, most flashing will not be visible to a home inspector. However there are clues that we can use to help us determine if flashing was installed and if further investigation may be warranted.

  • Attached Decks – Decks that are attached directly to a house that are not flashed almost always rot the wood areas they are lagged into. If possible, crawl under the deck to verify flashing and look for moisture / rot.  From the basement or crawl space look closely at the rim joist and areas of sill for discoloration or rot. Because these structural members are thick, it may take a while for it to manifest. If there is insulation present, ensure you note it in your report. Foam insulation creates an even bigger problem. Before the homeowner sees any damage, it will be too late. Any deck that is pitched toward the house would also be considered a defect. Close examination in the area where the deck is attached is most important.
  • Window and Door Openings – Although impossible to see during a home inspection there are clues we can look for. Any moisture around a window viewed from the interior most likely indicates that flashing is missing or improperly installed. Look for exterior “puckering” on stucco or EIFS below window or door openings.
  • Window & Door Drip Cap Flashing – If this is installed properly you should be able to see this during a home inspection. Look at the top and upper sides of the door / window. The flashing should wrap around the trim. CLICK HERE or the “News From The Home Inspector World” link in the newsletter for a brief video detailing drip cap flashing.
  • Lower Areas of Siding – Look below a starter strip, on top of any masonry that protrudes past the siding, and below masonry veneer. It is very popular to first have several feet of stone or brick followed by vinyl siding. We have seen water penetration and damage because flashing was not installed under the siding and over the masonry. The flashing should be visible and calked to the masonry veneer. Brick veneer siding should have weep holes with screens and flashing below the first course.
  • Trim – Flashing should be installed above and below all exterior trim. This trim will be visible during a home inspection.
  • Other Penetrations – These areas will also be difficult to see if flashed. However we may be able to see where the siding meets the penetration evidence of flashing. CLICK HERE for a brief video detailing exterior flashing.

I have renovated many homes, old and new alike and rarely have I seen all of the exterior penetrations properly flashed. When inspecting the exterior make a mental, or actual note of the areas that should be flashed so when you are on the inside you can closely inspect the areas for signs of moisture. Don’t move through the interior inspection so fast. Take your time and pay close attention to the areas you noted when inspecting the exterior.

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