There are several possible causes of soggy pastry. One is that oven temperatures vary and the only way to be sure your oven is the correct temperature is to use an oven thermometer
. A pie that is soggy inside may not have been cooked for long enough; or a precooked filling may not have cooled sufficiently before being covered with pastry.
Too much liquid in the filling can wet the pastry lid. Fruits combined with sugar require only a little water as they will exude juice during cooking. If you are layering fruit with sugar, make sure the last layer is fruit before the pastry lid is added: if the sugar comes directly into contact with the pastry, it will make it soggy. A hole or cross cut in the top of the pie allows steam to escape from a covered pie and keeps the pastry crisp.
** Cooking Thermometers