Hi, I have a stand alone garage that sits back in my garden. It's approx 40 years old and built with a single brick wall. We have just had a freak rain storm lasting around 20 minutes leaving floods everywhere, when I went into garage there was an inch of water on the floor. I immediately looked at the ceiling but it is dry, the floor is concrete and painted with sealer and the front is water tight. So, my question is this, is it possible that the water could coming through the mortar at ground level were it was sitting on the slabs and soil on the outside ??