Basic Waterproofing for Basements

by Nick Gromico and Ethan Ward

 

 

Water Damage Concerns

 

Basements are typically the area of a structure most at risk for water damage because they are located below grade and surrounded by soil.  Soil releases water it has absorbed during rain or when snow melts, and the water can end up in the basement through leaks or cracks.  Water can even migrate through solid concrete walls via capillary action, which is a phenomenon whereby liquid spontaneously rises in a narrow space, such as a thin tube, or via porous materials.  Wet basements can cause problems that include peeling paint, toxic mold contamination, building rot, foundation collapse, and termite damage.  Even interior air quality can be affected if naturally occurring gasses released by the soil are being transmitted into the basement. 

Properly waterproofing a basement will lessen the risk of damage caused by moisture or water.  Homeowners will want to be aware of what they can do to keep their basements dry and safe from damage.  Inspectors can also benefit from being aware of these basic strategies for preventing leaks and floods.

Prevent water entry by diverting it away from the foundation.

Preventing water from entering the basement by ensuring it is diverted away from the foundation is of primary concern.  Poor roof drainage and surface runoff due to gutter defects and improper site grading may be the most common causes of wet basements.  Addressing these issues will go a long way toward ensuring that water does not penetrate the basement.

Here are some measures to divert water away from the foundation:

 

• Install and maintain gutters and downspouts so that they route all rainwater and snow melt far enough away from the foundation of the building to ensure that pooling does not occur near the walls of the structure.  At least 10 feet from the building is best, and at the point where water leaves the downspout, it should be able to flow freely away from the foundation instead of back toward it, and should not be collecting in pools.
  
• The finish grade should be sloped away from the building for 10 to 15 feet.  Low spots that may lead to water pooling should be evened out to prevent the possibility of standing water near the foundation.
  
• Shallow ditches called swales should be used in conditions where one or more sides of the building face an upward slope.  A swale should slope away from the building for 10 to 15 feet, at which point it can empty into another swale that directs water around to the downhill-side of the building, leading it away from the foundation.

Repair all cracks and holes.

 

If leaks or seepage is occurring in the basement's interior, water and moisture are most likely entering through small cracks or holes.  The cracks or holes could be the result of several things.  Poor workmanship during the original build may be making itself apparent in the form of cracks or holes.  Water pressure from the outside may be building up, forcing water through walls.  The house may have settled, causing cracks in the floor or walls.  Repairing all cracks and small holes will help prevent leaks and floods.

 

Here are some steps to take if you suspect that water is entering the basement through cracks or holes:

 

• Identify areas where water may be entering through cracks or holes by checking for moisture, leaking or discoloration.  Every square inch of the basement should be examined, especially in cases where leaking or flooding has not been obvious, but moisture buildup is readily apparent.
  
• A mixture of epoxy and latex cement can be used to fill small hairline cracks and holes.  This is a waterproof formula that can help ensure that moisture and water do not penetrate basement walls.  It is effective primarily for very small cracks and holes.
  
• Any cracks larger than about 1/8-inch should be filled with mortar made from one part cement and two parts fine sand, with just enough water to make a fairly stiff mortar.  It should be pressed firmly into all parts of the larger cracks and holes to be sure that no air bubbles or pockets remain.  As long as water is not being forced through basement walls due to outside pressure, the application of mortar with a standard trowel will be sufficient if special care is taken to fill all cracks completely.
  
• If water is being forced through by outside pressure, a slightly different method of patching with mortar can be used.  Surface areas of walls or floors with cracks should first be chiseled out a bit at the mouth of the crack and all along its length.  Using a chipping chisel and hammer or a cold chisel, cut a dovetail groove along the mouth of each crack to be filled, and then apply the mortar thoroughly.  The dovetail groove, once filled, should be strong enough to resist the force of pressure that was pushing water through the crack.

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Hiring a Home Inspector

Hiring a Home Inspector

When it comes to hiring a Home Inspector, most buyers never ask the right questions.

Here are the Top 5 questions to ask when searching for a Home Inspector:

1. Experience - How much experience does the inspector himself have? The company may have been in business for a long time, however, the inspector may be brand new.

Always ask, who will my Home Inspector be?

2. Credibility - How long has the company been in business and will they stand behind their reports?

3. License or Certifications - Is the Inspector licensed by the State and is he certified with any Professional Organization?

4. Errors and Omissions Insurance - Who is the holder of the inspectors E&O Insurance?

5. Reports - How long will it take before I receive the report and is it computer based with images?

Construction Methods and Materials for Noise Control

by Nick Gromicko and Ethan Ward

In any heavily populated area, there is enough activity going on at once during the day to generate all kinds of sounds across the audible spectrum of human hearing. Planes take off and land, traffic moves along roadways, construction crews repair roads, dogs bark, music blares, sirens sound, lawns are mowed, etc. Even within a building, mechanical noise from heating or air conditioning can be audible, phones ring, and voices, radios and TVs are heard through walls, and so on. We rely on construction practices and materials to provide a sufficient barrier from the loud goings-on that surround us every day. Inspectors may be interested to learn how building materials and techniques influence the transmission of sound.

How Sound Moves

Sound energy travels from a source through air, water and solid objects. When sound waves hit the eardrum and cause vibration, we perceive them through our sense of hearing. The path a sound takes before it reaches our ears can be either airborne or structure-borne. Airborne sounds are radiated from a source directly into the air, such as a loud jackhammer. Structure-borne sound is sound that travels through solid materials before we hear it. An example would be heavy footsteps audible from the next room. This is why structure-borne sound is often referred to as "impact noise." Sound waves radiate around the source and decrease in loudness as they travel farther away. The energy of a sound wave is reduced by half when the distance from the source doubles.

Sound has three properties: frequency, wavelength and amplitude. Frequency is the number of cycles per second the sound wave itself produces, and it determines the pitch of the sound we hear. Frequency is measured in hertz. The range of human hearing goes from 16 to 20,000 Hz, with 16 being the lowest detectable pitch, and 20,000 the highest. Wavelength is the distance between the start and the end of a sound wave cycle. Amplitude is the perceived loudness of the sound.

Systems of amplitude measurement have been developed in order to quantify sound objectively. When amplitude is measured, it is actually the pressure of a sound wave striking a surface that is being measured. The unit of measure is the decibel (dB). A larger vibration at the source will cause a larger sound pressure level and, thus, a greater perceived volume. The human voice is usually in the range of 55 to 60 dB, a loud truck or motorcycle is 80 to 100 dB, and a jet taking off or a gun firing is measured at 120 dB or more.

Reducing dB Levels in Buildings

There are several categories of sound control for interiors: sound absorption, airborne sound transmission, and impact-sound transmission.

Sound Absorption

Sound absorption is the capability of a surface, or building material, to absorb sound instead of reflecting it. Sound waves will continue to bounce around a room for a time after they are created if the majority of surfaces in a room is reflective. Surfaces that absorb sound better will not allow for reflections to bounce around as much, and will deaden the sound wave more quickly. Many common building materials, such as gypsum board, wood, concrete, brick and tile, are fairly reflective and do not absorb much sound. Softer materials, such as carpet, foam padding, and fiberglass insulation, are far better at absorbing sound.

The use of absorptive materials can be helpful in controlling sound. Fiberglass insulation is very absorptive and can be used where sound control is a concern. Thick carpet with padding is also very absorptive, and acoustical ceiling tiles are designed to absorb rather than reflect sound. Even in cases where these options are not viable, absorptive materials can be added to finished rooms in other ways: furniture with thick cushioning is extremely absorptive, as are thick and heavy curtains and drapes. Items such as these can be added or arranged in ways that will allow for greater sound absorption. Acoustical baffles with absorptive materials can be purchased for use in areas where sound is a major concern, and most are designed to be unobtrusive and visually nondescript so as to allow for installation without drastically altering the aesthetics of a room.