My brick chimney looks terrible. The mortar is crumbling, the brick are spalling and there is efflorescence on the chimney bricks. About 8 years ago we put in a new direct-vent furnace and the only thing left venting up the chimney is the water heater?

Your orphaned water heater may very well be the problem. It's possible, that after removing your furnace from the chimney, that your flue is now too large for just the water heater. Every water heater has a minimum and maximum vent size provided by the manufacturer-check your requirements. Oversized flues can contribute to at least 3 problems: poor draft, chimney corrosion and freeze/thaw damage to the chimney. If your vent is too large, there are 2 solutions. You either line the chimney or change the hot water heater to a sidewall vented unit. Don’t forget to repair or take down your brick chimney. This is a potentially dangerous situation as appliance attached to oversized flues are likely to back draft, increasing the danger of carbon monoxide inside a home.

Why are my foundation walls are damp and sometimes wet?

For an average 2,500 square foot home, one inch of rainfall or the equivalent amount of melting snow will result in 1,500 gallons of water rushing off the roof, all of which will seek out and find the easiest path into the ground. The first line defense against a leaking foundation is to send this water away from the house by sloping the ground surface down, away from the house over the first 10 feet. Keep the grade as high as possible close to the house. Be sure to consider the type of siding you have on your house when raising the grade. Keep gutters and downspouts clean and extend your downspouts at least 10' away from the house. Keeping roof and surface water away from the foundation may solve your problem.