A moisture investigation is an inspection for water damage, moisture and potential mold problems. It is useful to have a moisture meter for parts of this investigation

• WALLS. Arbitrarily check wall surfaces for moisture using the moisture meter, especially those with stains or in places where there is a history of water leaks. Check near baseboards, especially around exterior walls. Check around windows and exterior doors. Compare readings from various locations to see if one wall is higher than others. Other suspect areas are those with water stains, loose wall paper or peeling paint.
• CEILINGS. Stains on ceiling or celing tiles are suspect areas. Check them with the moisture meter. In office buildings with suspended celing tiles, do not remove or lift them. There may be mold on the backside of ceiling tiles with water damage which when disturbed may aerosolize spores. If  management desires to inspect for mold, have them remove a neighboring celing tile that does not have a stain and use that as a way to inspect adjacent, suspect areas of the ceiling cavity.
• CARPET. In bathrooms or under window sills in rooms with carpet, pull  up carpet enough to check the backside for mold and to inspect the carpet taking. Rusty or discolored nails on the carpet tack are indications of a past or present moisture problem. Carpet should be avoided at the entrance to the building and where high moisture content is probable such as kitchens and bathrooms. Damp carpet is a breeding ground and reservoir for mold spores, dust mites and other microorganisms.
• CONDENSATION. Check for condensation around windows and skylights.
• PLANTS. Check under pots for mold growth from over watering or spillage.
• AQUARIUMS. Check under aquariums for mold growth from spillage or pump leaks.

• TOILET. Check around toilet base with moisture meter. Check wall behind the toilet under the water shut-off valve and along the baseboard with moisture meter for leaks in plumbing. Check the back of toilet bowl for condensation and mold growth.
• TUB/SHOWER. Check for missing or cracked tile. Check for missing caulk or cracks in grout. Check surfaces with moisture meter. Check around fixtures and soap dish with the moisture meter. If reading are elevated take readings in various areas and compare to each other. It only takes the smallest crack in grout or caulking to allow water to penetrate into walls and allow for mold growth. It is highly probably that mold exists behind water damaged shower walls and cracks in grouted tile.
• SINK PLUMBING. Check under sink for leaky supply valves and fixtures. Touch the bottom of the drain trap. Often when there is a slow leak there is a drop or two of water on the bottom of the trap that will alert you to the slow leak.
• FANS/VENT. Check that there is an exhaust fan in the bathroom, that is works and it vents to the outside. Some fans do not exhaust air.

• SINK AREA. Check for cracks in grout or missing caulk around back of sink.
• SINK PLUMBING. Check under sink for leaky supply valves, leaky fixtures and leaky drain pipe fittings. Touch the bottom of the drain pipe. Often when there is a slow leak there is a drop or two of water on the bottom of the p-trap that will alert you to the slow leak.
• UNDER SINK. Check for evidence of water damage.
• Check the refrigerator pan. It should be cleaned twice per year.

• DRYER VENT. Check that dryer vents to the outside and the ducting is not kinked, clogged, or have holes in it. The dryer should not vent into the garage or crawl-space. If the duct is clogged replace it or have it cleaned by a professional duct cleaner.
• HOT WATER HEATER. Check surfaces around the hot water heater for evidence of water damage and active water leaks from plumbing or a corroded heater.

• Obtain a relative humidity gauge and record RH indoors. These can be purchased from Radio Shack or Home Depo. Poorly ventilated showers will cause excessive high humidity and moisture, which can cause mold growth. If there is no exhaust fan, suggest opening the window when showering. Moisture from the washing machine if not vented will provide moisture for possible mold growth. Cooking also contribute to high humidity. Use ventilation or exhaust fans in these areas as necessary. The ideal relative humidity (RH) range is 40-60%, with 50% ideal. Mold growth is prevented below 60% RH. Dust mites cannot live in environments with less than 50% relative humidity. Too dry of an environment is also not good.

• Inspect the exterior of the building for potential problems that would allow moisture to penetrate into the interior. Think like a stream of water. Water flows down hill in the path of least resistance. It only takes a pin-hole size crack to allow moisture in. If moisture gets in how will it dry out? Are there weep holes in windows and stucco walls. Can moisture dry to the outside, or will it be trapper inside a wall cavity?
• Foundation. Check for loose mortar joints, cracks, and efflorescence.  Efflorescence may be either white or colorful (orange for example). It may look like mold but it  is actually mineral deposits leaching from the building material.
• FOUNDATION GRADING. The slope of the soil next to the building should be away from the building, not toward it.
• Pavement grading: The slope of any pavement, sidewalks, etc, next to the building should be away from the building, not toward it.
• Roof. Check the roof for popping nails, missing or curling shingles, flashing problems.
• Down spouts. Check for loose, missing, leaky joints at down spouts. Down spouts should drain away from the house and not too close to the foundation.
• Gutters. Check for loose or clogged gutters. Gutter should be sloped properly.
• FACIA Check the facia (woo at the edge of roof line) for deteriorating or water damaged wood.
• Siding: Check siding for cracks, damage, missing or loose pieces, missing caulk, peeling paint and nail &screw holes.
• Windows: Check for peeling paint, unprimed wood, cracks in wood,  rotted sills, condensation.
• Porch / PATIO Check for roof leaks,  moisture stains or damage, mold growth.
• SPRINKLERS Sprinklers should not be hitting the side of the house which may cause stucco or siding to deteriorate.
• Leaky faucets (drip, drip...)

• It is suggested to wear a tyvex suit or disposable coveralls and to wear as respirator when going into crawlspaces and attics. Not to protect against bugs and spiders, although that’s not a bad secondary gain. Crawlspaces have pesticides including termitecides. Older homes may have pesticides so toxic they are no longer legal in the United States to apply. Some of these do not break down and may be in the soil decades after applying. If you see a lot of dead bugs laying around in the crawlspace you should wonder about what’s down there.
• Check plywood sub flooring behind fiberglass batt insulation for mold growth and deteriorating/rotten wood, especially around plumbing in bathroom and kitchen areas.
• SOIL. Soil should be dry. Is it damp or wet? Are there drainage issues.
• Is there a sump pump or floor drain? Do the pump work. Is there standing water in the pump or drain.
• Is there any earth-to-wood contact? Earth to wood contact is prone to termite damage as well as mold growth and rot.
• Is dryer vented into crawl space. It should vent to the outside.
• Is there excessive cracks or evidence of water intrusion from leaks in foundation.  Efflorescence is a sign.
• Evidence of critters intrusion. Protein in rat and mice urine becomes a potent airborne allergen when it dries.
• Evidence of termite treatment
• Evidence of mud tubes.
• Stored materials, boxes, cloths, paper - cardboard boxes in contact with earth will grow mold.
• Insufficient ventilation / closed vents / vents with critter holes in screen / missing screens.
• SILL visible mold / evidence of water intrusion / water damaged / water stains.
• FLOOR JOISTS: Mold growth in locations____________________________
• SUB FLOOR mold present / staining / rotten / previous repairs made.
• PLUMBING current leak / evidence of past leak.

• It is suggested to wear a tyvex suit or disposable coveralls and to wear as respirator when going into crawlspaces and attics. Not to protect against bugs and spiders, although that’s not a bad secondary gain. In attics there is insulation. Fiberglass fibers are a probable carcinogen. The blown-in cellulose insulation commonly found in new homes is said to be non-toxic. It contains a borates for fire retardant. However there are a lot of small dust particles generated when it is disturbed. In older homes the blown-in insulation may contain vermiculite, a carcinogen.
• INSULATION Check for dirty, wet or  water damaged insulation.
• VENTILATION. Check for adequate ventilation.
• TRUSSES /FRAMING/SHEETING. Look for visible mold growth, moisture stains. Take reading of suspect wood and sheeting surfaces with moisture meter.