Our 14 year old home has a dampness problen in the finished basement. We have owned the home for 2 years and last summer had a problem with the dry wall rotting due to moisture. We had a contractor dig up to our footing and he found that we do not have any drain tile around the house. We have a sump pump in the house that drains many times a day. This is not stopping the water from pushing up against the outside of the foundation. Would an exterior sump pump help? We have some underground streams in our neighbourhood and the soil has lots of clay in it.