Basic Waterproofing for Basements
by Nick Gromicko
This article describes the many methods to addressing moisture in basements and foundations. The key is diverting water away from the home at the exterior. Once these measures have been taken, then other waterproofing and treatment methods can be applied to the interior of the basement in order to reduce moisture.
During an inspection, one of the quickest methods in determining a potential moisture problem is the presence of efflorescence. Efflorescence is a white chalky substance (dissolved salts) left on porous building materials after water has evaporated once it has transported through the material. This method of transportation is known as capillary action.
Evaporation drain line on furnace should be checked out from time to time for any blockage which could cause backups in drain pan causing water damage to floors and subflooring and other structul issues and damage to the drain pan as well
Two conditions are essential to support biological growth: nutrients and moisture. These conditions can be found in many locations, such as bathrooms, damp or flooded basements, wet appliances (such as humidifiers and air conditioners), and even some carpets and rugs
I found this in an attic. Many dryer vents are vented up through the roof in Florida. It had been leaking so someone tried to seal with some sort of rubberized putty. It actually made it worse as the water was trapped between the putty and sheathing causing rotten wood around the vent.
This picture serious water damage along a window sill. It appears that a storm window was removed and the siding sill flashing was holding water on the window sill and not allowing it to drain properly. The eave of the house is very short and does not have guttering, adding to the problem. The home owner is going to have substantial water damage in the walls.
This image shows possible water intrusion points. The downspout should be extended 5 feet from the foundation. There should be more separation between the siding and the ground. If weep holes are present at the bottom of the brick veneer wall, they are likely covered by soil.
The article “Moisture Intrusion” talks about how air movement accounts for 98% of moisture getting into building cavities. Where there is moisture, there is a possibility of mold. Mold for people with allergies and asthma can be harmful, if not fatal. But its never good for anyone or any structure.
An image on foundation drainage shows the exterior wall with a waterproofing material.A drainage pipe located at the base of the foundation that would connect to a sump pump. The drainpipe would be covered with gravel and back filled and compacted with soil.The surface grade would slope away from the house with a 6 inch fall in 10 feet.
This photo shows efflorescence built up on the foundation walls. This shows that the wall has been exposed to water on the outside of the wall. Fuhrer investigation is required to determine the cause of the build up of efflorescence.
I originally thought i would not need a moisture meter for my inspections. After reading “Moisture Meter for Inspectors” my opinion is staring to change. I think that the meter can be extremely helpful if it can help me “chase the leak” to the starting point.
Here we have a wood shake roof covering material in bad condition. We can see there is major deterioration in the shingles themselves and many are broken or missing. This can lead to major water intrusion into the perimeter below and also cause major debris building up in the gutter system. I see also some exposed fasteners with no sealant which can be a direct penetration for water intrusion and also a missing fastener which is a direct penetration to the roof sheathing. That can allow for some major moisture buildup between the roof sheathing and roof covering material or even beyond. Which can be causing some mold friendly environments and destructive nature to the components of the building.
Article: Roof Underlayment Types: There are three basic types of underlayments used under the roof covering materials. The first and most commonly used in steep slope roofs is asphalt-saturated felt. This type of underlayment can fail much sooner than the life expectancy if applied on a low sloping roof. The asphalt-saturated felt tends to absorb water much faster than other types which results in wrinkling of the material and ultimate failure. This is the reason this type of underlayment is used almost always on steep sloped roofs.
With discussion in regards to the gutter downspout extensions, I have noticed that it is common to see the down spouts without extensions. As pictured here, this is a deficient item that could possibly cause soil washout around the foundation, possibly resulting in major issues.
In regards to the wall assembly I have learned about the proper construction needed in certain climate areas to help keep water and moister out while at the same time allowing the moisture to escape. Walls that aren’t properly designed as mentioned can cause issues with allowing the escape of moisture resulting mildew and mold.
I commonly see bathroom vents installed poorly in our area. Most are simply directed towards roof vents, with no sealed connection present. The problems such as mold growth in the attic often take many years to develop. Therefore, it is sometimes difficult to convince contractors of the importance of this issue.
I commonly see bathroom vents installed poorly in our area. Most are simply directed towards roof vents, with no sealed connection present. The problems such as mold growth in the attic often take many years to develop. Therefore, it is sometimes difficult to convince contractors of the importance of this issue.
As the picture shows, after the vapor barrier was installed in this crawl space someone took the time to glue patches of a similar mil plastic sheeting over the tares that have occurred but they never completed the job as a 4 inch tear was present less than a foot from the patch. This picture also shows evidence of mouse or other small rodent intrusion by way of the nest made from the pink fiberglass insulation under the vapor barrier.
As shown in picture (picture&id=2552) from the Nachi gallery, proper extensions on the base of the downspout coupled with a positive grade along the foundation wall help to direct water run off away from the foundation of the home and allow it to safely drain into the soil without ponding against the foundation wall which could lead to water intrusion.
