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Hail Damaged Roof Replacement: Part 7 – Rotted Roof Deck Repair

Bob Jackson
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by Bob Jackson

This project is continued from Hail Damaged Roof Replacement – Part 6.

Rotted roof deck panels caused by water leaks were discovered the during the new roof installation after a hail storm. The source of the roof leak is traced back to toe boards the home builder nailed through the shingles and filled with caulk. This article explains how to repair the rotted roof deck panels.

Roof Leak and Rotted Roof Deck

The roofing crew discovered rotted roof decking while stripping off the old hail damaged roof. This problem had nothing to do with the hail damage. The OSB deck board water damaged and stained with two holes where water leaked in around caulked nail holes in the shingles. The roofers tested questionable areas with a hammer for structural strength, which enlarged the soft mushy holes in the deck as seen here:

Roof Leak and Rotted Deck Due to Nail Holes in the Shingles

Finding the Roof Leak

I’d known there was a roof leak somewhere in this area because I’d notice a water stain on the plywood ceiling of the porch roof. The yellow arrows point out several caulked over nail holes in the shingles. This area gets a lot of water because it’s below the gutter spout as seen during this rain shower:

Roof Leak Around Caulked Nail Holes in the Shingles

At least six caulked over nail holes are seen in the photo below as gray bumps. I know from the building inspector’s reports made when my home was built in 2002 that the home builder did a poor job because the inspector caught the roofers installing shingles without roofing felt! The inspector made them redo that part of the roof.

My guess is the roofing crew nailed toe boards or roof brackets through the shingles (always a bad practice!), then filled the holes with gray caulk. Over time, the caulk worked loose and began to leak.

Roof Leak: Caulked over Nail Holes in the Shingles

The severe granule loss, scabbing and blistering of the discontinued faux dimensional Atlas Chalet shingles is also evident in the above photo.

This the roof leak as viewed from inside the attic. Water is dribbling along the rafter beneath the roof deck, down the inside of the fascia board and onto the soffit. The water then ran on the soffit to the left against wall.

Roof Leak: Attic and Soffit

This makes four (4) roof leaks since I’ve owned house in the following locations:

  1. Cracked/split plumbing vent boot.
  2. Gas flue vent.
  3. Leaky chimney.
  4. Caulked nail holes through the shingles – this current problem.

Home ownership is always an adventure!

Closeup of the deterioration caused by the leak to OSB roof deck:

Leak Damage to Roof Deck

Roof Deck Leak Repair

The roof rafters, fascia board and soffit were water stained, but otherwise structurally in good shape, as was were the rafters and headboard inside the porch roof. The water damage was limited to the OSB deck panels, where the leak attacked the adhesive in the OSB causing it delaminate and weaken. Fixing the leak is simple: replace the rotted deck panels and install the new asphalt shingle roof in the normal way; just don’t do bonehead things like driving nails through the shingles and caulking the holes!

The two affected OSB deck panels were removed – a straightforward job of pulling up the nailed panels with a hammer and pry bar:

Roof Deck Leak Repair: Replace the Rotted Deck Panels

This photo shows how the leak dribbled down the rafter onto the soffit, then ran towards the wall. Fortunately the roof flashing did it’s job and prevented the water from getting inside the main wall of the house:

Roof Leak: Water Stains on the Soffit

New OSB deck panels being installed:

Roof Leak Repair: New OSB Roof Panels

Gable Roof Leak

The roofing crew discovered more caulk-filled nail holes in the shingles on the gable roof. The gray colored caulk is highlighted in the yellow square – directly in front of the gutter downspout where water will pouring over the caulked holes.

Gable Roof Leak: Caulked Nail Holes in the Shingles

The original roofing crew working for the home builder was very careless by driving nails through the shingles, probably to fasten a rope or toe board. Here’s a closeup of the caulk filled nail holes:

Three roof leaks were found when the shingles were torn off, causing the OSB to soften and rot. (Downhill is towards the left.) The rotted OSB panel was removed and a new section installed.

Roof Leak: Water Damage to the OSB Roof Panel

The cost for replacing the three panels was $48 each (charged per repair, even if it’s less than a full 4 x 8 ft panel) for a total of $144. This repair was not covered by the hail damage insurance claim. In my opinion, it was well worth the price.

This series is continued in Hail Damage Roof Replacement – Part 8.

Take care,

Bob Jackson

building inspectorcaulkfascia boardhow tonail hole
Bob Jackson
Bob Jackson
Technology product manager by day and a prolific handyman in the evenings and over the weekends. Bob was the founder of the original Handyman How To website and that tradition continues on this site with excellent new handyman content into the future.
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