Bitumen Facts

Bitumen is seeing a renewed use as a exterior waterproofing sealant and while there are some practical uses it is generally very job specific.

Bitumen is mined from tar sand. The most well known being the Tar Sand pit in Alberta Canada. The area is larger than England and is a source of great environmental controversy.

  • Bitumen is too thick to be pipelined and must be shipped in its actual state.
  • To ship via pipeline Bitumen must be diluted using, among others the following: natural gas, naphtha,synthetic crude and benzene.
  • One ton of tar sand produces merely 104 pounds of oil. The rest is discarded waste.
  • It requires 40+ gallons of water to produce a gallon of Bitumen.
  • Benzene is a well known carcinogen and local autoimmune disease and cancer increase exponentially in its presence.
  • Bitumen is actually many times more corrosive than standard oil. It has proven to corrode metal pipelines. Applying this material to foundation walls greatly shortens their lifespan and strength.
  • The Bitumen manufacturing process is considered to be the most wasteful and environmentally irresponsible practice the oil industry has enforced to date.

The absorption is sufficient to allow water to pass through to a foundation wall though not enough to allow drying. This ages the wall unnecessarily and weakens the concrete substantially. The use of this material in waterproofing is becoming more prevalent as contractors, already faced with massive material cost increases, jostle to find cheaper alternatives to waterproofing foundation walls.

While the use of Bitumen is clearly environmentally irresponsible there are some benefits although we know of none in the field of waterproofing that are not deleterious to the buildings foundation.

Will Grading Work

When will grading work?

The Basics:
Water flows downward only in the presence of resistance. If there is little resistance water simply goes downward.

The point above is this: Grading will only make a difference if it is actually stopping the water from soaking into the ground. This requires a very high degree of slope. A nearly unwalkable slope.

When water hits the ground it will simply soak into the ground. It only starts to run off when the ground is fully saturated.

If you basement is 6 feet underground and you slope your yard away at 3/12 slope it will be 24 feet from your house till the water run off is lower than you basement floor. This is a pretty serious slope and yet it will only lower the water volume by about 5% and the pressure at your footer/lower wall area by about 9%. This is pitiful performance for all the work of grading.

The Answer:
Grading becomes a real solution only when the ground outside is sloping toward the house over any considerable distance. This is normally not a landscaping issue but an “earth” issue and often requires a lot of dirt to be moved. If possible try to not have/remedy any areas that have large slope toward the house.

Many people will say, “installing drains to run the water around the house will fix the problem.” This is true! But.. those drains would have to be installed very deep. Installing drainage 2 feet deep when the basement is 8 feet deep will do nearly nothing but make a mess of the yard.

It is often found that some homes are simply in bad spots. There is sometimes not a practical outside solution. This is why so many try to approach the problem from inside.



Grading and Drainage

Apart from sealing the outside wall with sealants such as tar and vinyl coatings, the approach of grading the land outside away from the house is the most common approach to waterproofing basements. This is a logical and often an affordable approach of a few conditions exist:

1. Shallow basements next to lower ground.
Simply put: Your basement floor is only 2-4 feet underground and your yard slopes away from your house in such a way that the ground actually lowers to a level that is considerable lower than your basement floor. Under this scenario you could dig a drainage pit to the depth of the wall/footer across the foundation wall and then run the drainage to a place lower than your basement floor. Drains need to be quite substantial and installed with 6-10 inches of rock filter fabric underneath as well as fabric and rock above (at least a foot) to ensure the drains will not clog. The drainage needs a reasonable pitch: 2/12 or more.
No pitch. No drainage.
No lower ground. No drainage.


2. Shallow basements near a storm or other drain that you can attach to.
This is the same as above the only difference being that you would be attaching your drainage pipe to a preexisting drain. You should ascertain the guaranteed flow of the drain you will be attaching to. If it backs up “only in heavy rains” this will not do. You will really need this drain mainly “only in heavy rains”. This is a ver common mistake made when people connect their gutter to underground drains that clog easily in heavy rains.

Sometimes these drains belong to either the city or to your neighborhood association etc. If so you will need their permission to drain to it.

You may have noticed that grading alone is not mention. Grading is only considered a practical waterproofing measure under certain specific circumstances. Read about grading.

Water Facts

Water Facts
* Three-quarters of the Earth’s surface is covered with water, yet 98 percent is salt water and not fit for consumption.
* Less than 1% of all the water on Earth is freshwater usable for human consumption.
* More water is stored underground in aquifers than on the earths surface.
* The US uses about 350,000 gallons of water every day.
* The Us uses about 80% of its water for irrigation and thermoelectric power.
* There are 1.6 million deaths per year attributed to dirty water and poor sanitation (World Watch; World Health Organization)
* The average person in the US uses about 80 gallons of water per day. Toilet flushing takes up the largest amount of this water.
* Less than 1% of the worlds fresh water is accessible for direct human use.
* Humans can live for 7 or more weeks without food but hardly a week without water.
* The water cycle has 5 parts: evaporation, condensation, precipitation, infiltration, and surface run-off.
* At any one time, it is estimated that half the world’s hospital beds are occupied with patients suffering from waterborne diseases. (WSCC, 2004)
* In a hundred year period a water molecule spends 98 years in the ocean, 20 months as ice, about 2 weeks in lakes and rivers, and less than a week in the atmosphere.
* Water is the greatest factor in regulating the earths temperature.
* Water is the only element found on the earth that naturally occurs in three forms: gas, liquid, and solid.
* Over 90% of the worlds fresh water supply is in Antarctica.
* An average tree will give off 70 gallons of water a day in evaporation.
* It takes 2,072 gallons of water to make four new tires.
* It takes about 2 gallons of water to brush your teeth, 2 to 7 gallons to flush a toilet (but please don’t stop flushing…), and 30 to 60 gallons to take a shower.

Waterproofing Paints

I have inspected over 10,000 basements and have seen every engineering concept known to man applied in an attempt to prevent water from coming through a foundation wall. Still, every time, the water still ends up on the basement floor. I have seen some solutions really do a good job for a while only to find out that the “fix” only caused a more widespread problem.

Waterproofing paints have been around for decades and have been promoted enough that most people are aware of their existence and could name a few brands easily. The idea is that a “waterproofing” paint will adhere to the concrete better than regular paint and, at the same time fill the small pores in the block. In this regard every brand on the market will perform its job to perfection.

Until there is water.

To understand why this is you must understand two things:
1. The nature of bonded mixtures such as ceramics, concrete, metals etc.
It is not possible to bond metal to plastic or metal to concrete. It is also not possible to bond like materials together that were cured at different times. If you make a coffee cup with no handle and let it cure physics will not allow you to put a handle on later. The cup is already cured and set. Sure you could get some really good glue, but the handle will eventually fall off in the dishwasher (extreme moisture) or if jarred a bit. In the same way it is not possible to bond concrete to concrete if the two are different mixes done at different times. Any moisture causes expansion and contraction of both “different” elements/mixtures and it is this separate movement causes separation. Waterproofing paints ignore all of this. They are all a quick fix only designed to give the appearance of a solution.

2. Water is a very small molecule and paint is a very large molecule.
It is not, even in the slightest way, possible for a painted surface to retain water. Painting an object or surface, with any material, that has water in it (this includes any dampness, wicking, top down or bottom up moisture) is not waterproofing but painting.

So do waterproofing paints have any uses? Yes and no.
Yes, in the fact that they can prevent airborne water form penetrating thru them to materials below (the painted object). For example, if you have an area outside that never gets sunlight and is very slow to dry after a rain, this would be a good use for such paints.
No, if you are planning on painting the blocks in your basement. First, it will not stop actual water, but yet worse is the fact that it will prevent the blocks/wall from properly drying out after they have dampened after a heavy rain. This causes the block/wall to deteriorate at an accelerated rate.

If your home requires waterproofing consider these points carefully. The very worst situations I see are when people proceed with finishing or remodeling without taking the proper measures to deal with the water first.

Did My Gutters Cause My Basement to Flood

Did my downspouts cause my basement to leak?

Considering most basements are anywhere from four to eight feet underground, we have to considerthe conditions that are responsible for water intrusion. For example, what type of soil surrounds the home, how old is the structure, or perhaps how was the home constructed.
Most homes in the greater Washington D.C. area, for example, constructed in the last 70-80 years are fundamentally built the same way, that is, with a poured concrete footer supporting either a block or concrete wall. This cold joint (seam) between the footer and the wall, or the floor and the wall, is a primary weak spot in basements that experience water intrusion problems (no matter where the water comes from).
Clays of all types are found in this area of the country. Whether marine, plastic or sandy, clay was deposited along the greater Mid Atlantic area by ancient oceans and fresh water rivers. One characteristic of clay that most people are familiar with is its resistance to water infiltration. (Clay pots, for example)
The water table established in any neighborhood during a rain event is influenced primarily by the inches of rain falling and the number of square miles being rained upon. Rain becomes ground water and flows under the surface, past all the homes in a given area pretty much the same way, at the same depth. While a “false” water table is established during a prolonged rain event, it will eventually subside to normal levels during dryer periods.
The key here is that surface water running off of a single home will not penetrate the under-surface clay soil to the point of influencing the enhanced water table at any particular house. In other words, when it rains, it rains for many miles around the home with the leaky basement. Under-the-surface water, sometimes from many hundreds of feet away, and the great pressure of its own weight (water is pretty heavy), will find its way into a basement with a compromised seam between the footer and the wall. No  amount of surface water drainage enhancement or landscaping change will influence water 8 feet below the surface of a single home enough to prevent seepage thru a modern foundation (treated or untreated). If, however, your gutters are pouring water over the top of your foundation wall that is a different story entirely. The gutter pipes discharge should not be above the foundation wall anywhere.

Interior or Exterior Waterproofing

The following article is a brief overview of both interior and exterior waterproofing.

Exterior waterproofing is done in one of 3 ways:

1. Exterior Coatings
The earth around the exterior of the foundation wall is removed ideally down to the footer (this is the continuous concrete block that the wall sits on). The wall is then coated with either tar, vinyl or coated with more concrete (I will not cover coating the wall with concrete as it is a total fail in every way. Concrete does not adhere to older concrete and in the presence of any moisture the different layers of concrete will separate and crumble).

Covering the wall with tar is the most common approach. This is what the builder does. The wall is cleaned and then tar is sprayed onto the wall and footer. Tar is basically waterproof and the aim is to cover the entire surface and thereby prevent the passing of water thru to the lower layer. But the problem with tart is that it will very quickly get brittle and crack at the seam where the wall meets the footer (this is a natural point of movement as a house settles or the earth around it moves slightly -as in a heavy rain or a heavy drought. Under these conditions the ground expands and contracts considerably.). It is this point that is the most common point of water entry through the foundation.

Vinyl Sheeting the Exterior
The swift failure of tar is why most have taken to using vinyl sheeting in retrofit solutions. Vinyl doesn’t crack and is totally waterproof. The wall is cleaned and the vinyl is then adhered to the wall ideally to the footer. The problem with the vinyl, if it doesn’t tear and isn’t installed in a 1,000 pieces, is that it will never stay adhered to the concrete and the water simply goes around it back through the foundation. Also, if installed in many pieces the water may find a seam and get behind the sheeting. This is highly likely to happen as these materials once placed underground are very easily torn or detached from piece to piece.

2. Exterior drainage.
Most homes are built with a drainage system already intact. The fact that few of these survive much past 2-5 years -tops, is a testament to how ineffective these types of systems are and to how common poor installations are.

Exterior Drainage Pipes
This also involves digging out the outside foundation to a foot below the floor and installing a drainage pipe that will drain the water that builds up on the outside of the foundation to another nearby location. This requires an area for drainage near the building that is at least a foot or more below the basement floor. These designs are very common with builders. The percentage of these that survive even the refill of the dirt is surprisingly low (I would personally guess 30% survive without the pipes being crushed by the 7-10 ft. of dirt back fill with heavy equipment moving around above). After this the amount of mud and pressure from above is simply overwhelming. The drainage pipes under all that mud and stone are quickly clogged. It is a shame that heftier systems are not used as this is a good measure of prevention if done correctly. In Virginia, exterior basement waterproofing systems such as these are mostly prevented by the the presence of very dense clay. Clay is very small and will clog such pipes very fast.

Full Dig Out
3. Removing all the dirt is the last solution. It is rarely practical in residential homes, but is very common in apartment buildings where the owners decided to make apartments in the basement. The earth is dug out allow both for a patio and as a means to prevent moisture from entering now finished rooms. Interesting, in these designs you can always see moisture at the bottom the the outside wall. Moisture that would of appeared inside. This measure of full dig out is the absolute surest way of waterproofing from the outside as it prevents water from standing on the foundation. It is also the healthiest for the foundation itself.

Other Options
There is left only interior waterproofing, this is the most predictable and reliable solution.

Interior waterproofing is done by digging a trench around the perimeter on the inside of the foundation wall. In this trench is placed a pipe that collects the water as it builds up pressure under the floor and drains it into a pipe that then guides the water to a well. At the bottom of this well is a sump pump that then pumps the water outside and away from the home. These systems are away form the intense pressure of 7-10 ft. of mud and earth outside and are also much more easier to service and maintain. Preferably vapor barrier is placed on the wall and egressed under the floor.

What is Mold Remediation

Mold remediation is a two part process.
1. Removing Mold
2. Removing the cause of the mold.

1. Removing the Mold
Mold Removal is a fairly detailed process. The area must be thoroughly sealed with filtered fans (HEPA filtered fans) discharging to an outside area. Air in the containment area cannot recirculate or the spores will return. All debris must be bagged under containment and removed from the premises entirely. Specific moldicide must be used to kill any random spores in and outside of the containment area. If any of these steps are skipped or done in error mold will very likely return. Sadly, the mold may return even if all these precautions are performed correctly. This is why the second step is critical to success.

2. Removing the Cause of the Mold
The second stage is removing the cause of the mold. This is nearly always either a leak or some other source of water. It may be a plumbing, foundation, AC, roof, gutter, bathroom or kitchen leak. Whatever it is it must be repaired. Failure to do so will only result in the return of the mold.