QDEAR BARRY: Every time it rains, our sliding-glass door leaks. Water seeps in at the corners of the threshold, soaking the carpet edges and rotting the subfloor. We've tried repeatedly to caulk and seal these thresholds, but nothing seems to work. Is there anything we can do to solve this problem? -- Jay

ADEAR JAY: Water leakage is a common problem with sliding-door thresholds. Sometimes water intrusion is severe, staining carpets and causing dry rot at the subfloor, baseboards and even the wall framing. Caulking is the first line of defense, but this does not always help. Your idea to add flashing is a good one, but even this is not always effective.

There is a fail-safe way to fix the problem, but it is intrusive, costly and recommended only after all other methods have failed.

This repair involves installing a sheet metal drain pan under the door threshold. The pan must be ordered from a sheet metal shop and fabricated to fit the doorway. Three sides of the pan should have a raised edge, about 3/4-inch high. The fourth side should face toward the exterior of the building, with a downward sloping flange to promote drainage.

To install this pan, the entire door assembly must be removed. Once the doorframe is removed, the pan can be set in place, using plenty of high-quality exterior caulk. The door assembly is then reinstalled, with the threshold inserted into the pan, again with generous amounts of exterior caulk.

If all sliding doors were installed with this sort of pan, leaks could be prevented at minimal cost.

DEAR BARRY: My neighbors have a very old home, built before the age of building codes, and therefore, without a setback from the property line. They recently installed a new laundry, and the dryer exhaust now blows against the side of my house. The noise, lint and steam create a nuisance whenever they dry their clothes. I assume that this laundry was added without a permit and I am wondering if I should complain to them or to the building department. What do you suggest? -- Barbara

DEAR BARBARA: All plumbing and electrical alterations require a building permit. If the laundry was installed without a permit, the installation is not legal. It may also be illegal to vent a clothes dryer onto a neighbor's property.

You can discuss this with your neighbors to see if they are willing to make some reasonable adjustments, such as diverting the dryer vent to another spot. If they are not feeling neighborly, you can file a complaint with the local building department, but the cost of that action would be unfriendly relations with your neighbors.

Barry Stone is a professional home inspector. If you have questions or comments, contact him through his Web site, www.housedetective.com, or send mail to 1776 Jami Lee Ct., Suite 218, San Luis Obispo, Calif. 93401.

Distributed by Access Media Group