This year, being a beginner in handyman skills I decided to replace the deck boards and railings of my deck. When I bought the home about 1.5 years ago the professional who checked the house for me told me that the underlying structure is in good shape.
So, I started the demolition couple of days ago. One thing that's concerning me is after I removed the deck boards, I see the cracks on top of the joists especially where the previous screws went in with older deck boards. Rest of the joist looks good to me.
Now, do I replace the whole joist or can I do anything else to strengthen the structure ?
Note: My house is 17 years old. I'm assuming the current deck is at least 15 years old.