Q: As a general contractor in the Blue Ridge mountains of southwestern Virginia, we often build vacation homes higher than 4,000 feet altitude, where wind-driven rain is a regular weather feature. On one site, the wind regularly reaches 50 to 80-plus miles per hour and actually blows rain uphill. We have a south-facing window wall full of fixed-glass and awning windows. The wall has 2x6 studs, 1/2- inch OSB sheathing, Tyvek housewrap, and 1x10 horizontal ship-lapped pine. With only a 3/8-inch lap on the siding, I can imagine that water might be driven behind it. But how is it getting past the Tyvek and OSB through the wall? Water drips from the interior window head jambs, and with the interior wall paneling removed, it can be seen on top of the sole plate. We had to replace some buckled hardwood flooring after a vicious storm last January, and before we repair it again, we want to make sure the wall won’t leak. Are there any methods or materials that you could recommend?