Mold
 

We recently found out that we have a large amount of mold in our attic (we never use the attic). Apparently our bathrooms were never vented outside. We had our house built 25 years ago. Can someone recommend a company that is good at removing mold?:

All Brite Cleaning & Restoration in Gilford does mold remediation. Have used them for carpet cleaning before and was very happy with their work.

Besides removing the mold, you ought to alleviate the conditions leading to it. Basically, air with moisture is getting to the attic space, condenses on the under side of the roof deck when it's cool at night, and can't dry out. You need to install bathroom vent fans that vent properly outside. Put them on timers so they run long enough after showers to vent the humidity. Hunt around on the attic floor to find where wires penetrate the framing and give each a squirt of foam sealant. Same around any can lights, which are notorious air leakers. Improve the seal around any hatch into the attic. You also ought to have continuous ridge venting and continuous soffit venting. We had a similar problem with moisture in the cottage attic, back when we lived in it. Just adding the ridge vent made a huge difference, as the soffit area was not well sealed in the first place. The old gable end vents were woefully inadequate.

There is plenty of information over on greenbuildingadvisor.com (look for "how to do everything" - a list of links). Much of it is easy DIY.