Shear Panel Water Damage
Whenever you see damage like this,
there was probably a big problem that no one was aware of. Shear panel
water damage like this can only happen, if this area was to stay moist
for long periods of time.
To give you an idea, this damage was located behind a small set of stairs that was leading up to a wood deck. The stair stringers were securely fastened to the exterior of the wall and the roof was constructed in a way, to allow water to continually flow onto the deck every morning for about three hours.
This wasn't all that was going on in this area, the homeowners would frequently use the garden hose to clean the debris off of the deck and stairs on a regular basis. Both of these things only added to the problem.
These two problems weren't bad enough, this part of the house was located in the shade and the sun never shined on the wood deck. This rarely allowed for the moisture to evaporate out of the wood and sped up the wood damage process.
Only after the wood deck had completely rotted and needed to be replaced, did the contractor find out how much damage was actually done to the home. This type of damage isn't usually visible from the exterior, simply because the stairs were in the way.
Home Repair Tip: It wouldn't be a bad idea to contact a structural engineer for this type of repair, or remove the sheer panel and replace it. Make sure that you use the same type of nails and space them apart, the same distances that they were originally nailed.
It's always going to be better to use a mechanical blower or a broom to clean the debris off of your wood decks.