Outside view of the shop wall with the leak - it's about halfway down this wall on the inside. You need to look at the two likely causes to determine where the water is coming from.
• Ground sloping towards the wall instead of away.
• Water from gutter/roof system.
The ground is fairly flat here behind the wall. Slight slope from the neighbors yard but overall the grassy area behind the shop wall is fairly dry. No evidence of ground water moving towards the wall.
Always look up at the roof and gutters - even a small drip can lead to problems over time. Right above the location of the leak inside we can find evidence that the gutters have been overflowing and dripping. Note the pine needles and gunk residue from the overflow of this gutter system. The ground under this leak is soggy and muddy. We found the source of the leak.
How to fix (need to be comfortable with getting on a ladder - if you are not, hire someone to do it for you):
1. Look at the gutter system for clogs. Common spot to find it is in the downspout connection or inside the downspout itself.
2. Remove any clogs and debris from the downspouts and gutters. Ensure that water from the roof has a controlled path to the ground.
3. Look at where the water is coming out of the downspouts. Is there a splash block? Is there a connection to a drainage system? Water from the roof needs to be directed away from the foundation and allowed to go downslope away from the structure.
This is an easy problem to fix with just a little effort and time.
Brian Jovag, owner of Jovag Home Inspection.