 Paul Hope is the home and garden editor with Consumer Reports and says the high humidity with the heat can impact wood framing, sheathing and even doors, causing damage when those things swell and contract. The hot weather itself could be impacting siding, causing it to melt, especially when the sunlight may reflect off a neighbor's home and aim at your siding. He also says the pipes in that hot attic are not impervious to changes in temperature, so they can obviously shrink and grow with extreme changes in temperature.