SANTA ROSA HOME INSPECTION

Controlling negative pressure & excessive moisture condition in our Homes and Buildings

Studies have been conducted to measure pressure distribution and stack effect problems in homes and high-rise residential buildings.
It is important to understand how these problems of stack effect occur in our Homes and high-rise residential buildings to assist in developing solutions to these problems.
The designing of exterior walls that are airtight, and multiple, shorter elevator shafts in new high-rise residential buildings to control stack effect problems due to pressure differentials.

• Install air-lock doors at problem areas (i.e., elevator doors and entrance doors), and on the floors that are 50m up and down from the neutral pressure level (NPL) in already constructed high-rise residential buildings to control stack effect problems due to pressure differentials
• Keep air-lock doors closed during the cold season, and open for residents’ ease all other times of the year, since stack effect problems generally occur in winter.

The "Stack effect" is caused by natural convection and wind pressure. While a lower unit is suffering from a negative pressure and upper unit may have a positive pressure. Conditions can change with weather/season/barometric changes or even leaks in H.V.A.C. Ducts. Try holding a door or closed stairwell door just slightly ajar you can feel the pressure.

Watch your fingers.

So what’s the problem ? When we have a negative pressure in our homes this can cause a suction or pressure on the interior side of the exterior walls. Now if these walls are wet from rain the moisture/water will transfer from the exterior to the interior at areas around the windows, doors, sliding glass doors or cracks in the siding and any other opening in a wall. If there is a void this negative pressure will find it and if there is moisture it will transfer it to the interior of the walls. These condition will cause Excessive Moisture, Mold and Fungus Infection and Fungus damage or (Dry-Rot)

Call Ron Today! Your home inspection is so important to him… 707-696-8219