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Basement Waterproofing

Basement Waterproofing
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Basement Waterproofing

Water is the number one concern for residential and commercial property owners in the U.S. and especially in the D.C. Metro Area.. Regardless of whether you have foundation issues, water coming in from the sides, the roof, moisture issues inside the home, mold – water will always pose problems especially with developers and contractors cutting corners (they call it cutting costs). Waterproofing is an emerging industry and the science of waterproofing is constantly evolving with new technologies designed to keep water out of the home, especially the foundation – i.e., basements, crawl spaces, etc. The sources of water are rainfall, snowmelt, groundwater, water tables, and sometimes irrigation on the surface. The seasonal water table in many areas of Maryland, Virginia, and D.C is near or above the basement floor level at various times during the year.First, forget stopping water. It’s about managing the water through pathways of least resistance, drain systems that lead to paths of least resistance, and modern day technology to pump, de-humidify, truly water and moisture proof, and installing the correct system, correctly, whether outside or inside or a combination of both.There are three primary lines of defense that can prevent water problems in basements: (1) surface drainage systems, which include sub-soil systems and storm drainage systems; sump pumps pumping subsurface drainage above grade; proper extension of downspouts, cleaning of gutters; (2) subsurface drainage which includes foundation drain tile systems which sit down alongside the footing, below the floor level on either side – outside and inside; and (3) waterproofing and drainage on the wall surfaces, such as a Delta™ System.The goal of surface drainage is keeping the surface water away from the foundation by sloping or grading the ground surface and using gutters and downspouts for roof drainage, as well as swales, sub-soil systems, etc. The primary goal of subsurface drain systems is to intercept, collect, and carry away any water in the ground surrounding the foundation. The final line, waterproofing the walls is intended to keep the water from actually touching the exterior and interior wall surfaces – concrete, block, brick, stone, etc. Once it touches outside, it is only time stopping it from the inside. Once inside, then you usually have problems with mold first.
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Residential Basement Waterproofing

There are a variety of paths through which water can enter your home (See Causes and Solutions). There are a number of basement waterproofing systems which address these problems and are available with varying cost, effectiveness, and installation invasiveness. Depending on what company you hire, and their level of experience – whether they have adopted new technology instead of using older methods and older, cheaper materials – can determine the effectiveness of the solution. Some have evolved, some have not.We’re in the 21stCentury, and people are still installing the same system they installed 20 years ago, now generating complaints because those lifetime warranties need to be honored and serviced and are not. Some of the materials used with these systems are obsolete and are failing. If you use crushed gravel instead of round, washed gravel, or a silt sock or whatever ‘New Fangled’ system someone created – some of these systems are failing. We now have new polymer-based-materials, elastomeric and crystalline technologies, as well as more advanced membrane and structural bracing materials; better adhesives and injection materials to bind, seal cracks, stop water from infiltrating through holes, etc. We now have new instruments to diagnose, and we now have liquid rubber as opposed to the old obsolete and toxic tar. We have negative side wall applications that can waterproof from the inside when outside excavation is not feasible or cost effective or prohibitive.Interior and Exterior methods of waterproofing walls, crack repair and stabilization, and crawl space waterproofing, have advanced considerably. The Foundation Expert uses the most advanced products and proven systems available today. We are capable of just about anything, including completely waterproofing the basement envelope / environment and stopping the water from getting in from either side – negative and positive (interior and exterior). Although the Iowa State University says, “basements are not designed to be waterproof”, we believe they can be. Most contractors do not have the knowledge, experience, or even when they do, do not want to increase their costs. The Foundation Expert knows how to design and waterproof a new or existing basement or crawl space.

  1. Interior or negative side applications – Using this application, we are managing the water by allowing it to penetrate to a certain extent, and managing or stopping its direction or flow. Water, which enters at the cove (where wall meets floor), can be diverted to a sub or below floor drainage system, which is New Residential Code in Maryland and Virginia (See Causes and Solutions). At the end of this drainage system is a sump pump or two (or more) which discharges the water outside and away from the home. We have stairwell drains and window well drains feeding into these systems. Power back-ups are suggested. However, if water is coming through the wall, the fix is not so simple – a wall system or waterproofing system has to be devised to manage that specific flow. When properly installed, the sub-floor, interior systems may be just as effective as or more so than exterior drain systems, often at a fraction of the cost. Sometimes, not!

Interior Drain Tile and Water Management Systems are commonly recommended to address water, which seeps through the cove (where the floor and wall meet) or through floor cracks. The project takes 1-4 days, the procedure involves removing a portion of the floor along the perimeter foundation wall(s) about 12” to 18”, digging a wide, 12” deep and graded trench, alongside and down to the bottom of the footing; then laying round washed gravel, installing nothing less than 4” A.D.S. perforated drain pipe, which is then surrounded with washed gravel at the base of the wall covering the stone with a vapor barrier, and, installing a drain material like Miradrain® 2000R in alongside the wall which enters the trench and then sealing with a Portland cement finish.

On Concrete Block walls, we then drill weep holes to bleed the hollow cores, at every core and mortar seam. (See Video) Then, we run a wall drainage mat, over the weep holes, which allow the walls to continuously drain, covering the stone with a vapor barrier, and finish up with a Portland cement finish. The drainpipe (also called drain tile) either drains to daylight, or into large sump containers, with Zoeller Commercial Grade, Iron Sump Pumps to discharge the water up, and outside the basement.


  1. Exterior or Positive side applications – Waterproofing materials like epoxy, polyurethanes, hydraulic and waterproof cements, rubber, pre-molded membranes, drainage mats, etc., are used to waterproof and vapor seal the walls before water
    can penetrate through to the inside. (Your builder actually had to do this to pass inspection to sell the home.) Proper installation of perimeter drain tile in gravel, alongside the footing, with adequate means of draining away from the home should take care of drainage issues.

With existing structures, Exterior / Positive Side methods require excavation, sometimes down to the bottom or next to the foundation or footing. When structural issues are in evidence, outside excavation and repair may be the only solution recommended by an engineer (engineer’s report), necessary for a permit, and to be approved by a city, county, or municipal inspector. Exterior methods of waterproofing can be very effective but are usually more expensive, sometimes prohibitive depending on the application, the company, and other factors. However, sometimes you have no choice.

We are also capable of fully restoring the basement to a finished condition or completely remodel or renovate that or any space inside or outside.

Advances in Construction Waterproofing

Waterproofing every building or structure is an absolute necessity as conventional concrete itself will not be watertight on its own. The conventional system of waterproofing involves, drain mats and ‘membranes’ and drain tile(s). These rely on the application of one or more layers of membrane (available in various materials: e.g., bitumen, rubber, silicate, PVC, HDPE (High-Density Poly Ethylene), etc.) that act as a barrier between the water and the building structure, preventing the passage of water, and subsurface drainage. Regardless of theory, the membrane system relies on exacting real life application, which present difficulties. Problems with application or adherence to the substrate can lead to leakage.

Since 1990, the construction industry has had technological advances in waterproofing materials, including integral waterproofing systems, new polymer-based-materials, as well as more advanced membrane materials, and more knowhow through experience. With new construction, integral systems work within the matrix of a concrete structure, giving the concrete itself a waterproof quality for the first time. There are two main types of integral waterproofing systems: the hydrophilic and the hydrophobic (scared of water; tending not to combine with, or incapable of dissolving in water systems). A hydrophilic system (water lover; relating to or having a strong affinity for water – colloids swell in presence of water) typically uses a crystallization technology that replaces the water in the concrete with insoluble crystals. On a Molecular level, they bond and make stronger, more water-resistant. Today we have additives, like Aquafin™ or Xypex™ which are using crystalline technologies that when mixed with concrete create waterproof surfaces.

Various brands available in the market claim similar properties, but not all can react with a wide range of cement hydration by-products, and thus require caution. Hydrophobic systems (scared of water; tending not to combine with, or incapable of dissolving in water systems) use fatty acids to block pores within the concrete, preventing water passage. New membrane materials seek to overcome shortcomings in older methods like PVC and HDPE. Generally, new technology in waterproof membranes relies on polymer-based materials that are extremely adhesive to create a seamless barrier around the outside or inside of a structure.

Be Careful and Aware of Incorrect Methods Utilized by so called “Waterproofers”

These days, any contractor with a valid license (or without as our experience tells us) can call himself or herself a waterproofer. You, for example, can pay $35,000 to $75,000 to a License or Franchise operation – B-Dry, Basement Technologies, JES, Basement Systems, EverDry, and a host of others If you read their brochures, in their FAQ’s where it asks, “Do I need experience in this industry?” Their answer is. “No, although sales and business experience is a plus.” They will then give you two weeks training at corporate headquarters, they will sell you volumes of beautifully designed marketing brochures and materials, they will sell you product, which they have designed, manufactured, and ‘patented’, marking up that product and requiring you to use and purchase only their product.

You don’t have many options regarding ‘quality’ when you fix your basement and foundation. If you make a mistake with a window or door contractor, or with an electrician or plumber, it can be fixed. You don’t get ‘do-overs’ with a foundation and structural contractor, with a ‘waterproofer’ – when you repair your basement, you really need to get it right the first time. This is the foundation of your home – there is not a more important component to repair – EVER! READ THIS

“We bought our house and found out there was a water problem in our basement. During moderate rains, we would flood and water would continue coming into our basement for an entire day and with heavy rains, for longer periods. We hired a contractor to install an exterior system to the tune of $15,000. It didn’t work. He came out and did us a favor by modifying the system at a minimal charge. It still didn’t work and we had to replace our carpet 3 times which added another $5,000.

Our basement is about 1/3 of our square footage and the play room for our 2 young boys. Not having use of our basement was brutal to say the least. We spoke to our neighbors who had a system installed. So we called, and Sam came out; and then Jamie came in, fixed the problem for 1/3 of what we spent and about half of another contractor who gave us a quote. If I had a time machine! Sam and Jamie came in fast and did what they said and literally the day after they finished, we got 3 inches of rain and our boys played in our dry basement the whole time.” David Martin, Falls Church – one of our many references. His phone number is available upon request.

How do You Know?

How do you know if the contractor you are interviewing, who is giving you a “FREE ESTIMATE” (do you really think it is free? We give exact quotes, not estimations and we usually charge) is first, legitimate. Did they show you their license with their name or company name? In Maryland they need to show you a salesman license (still a sexist state). If they’re working on a home older than 1978, are they EPA Lead Certified? In other words, are they a Certified Renovator and do they display that emblem on their website? Are they Mold Certified and Licensed? Do they have valid insurance?

It’s not easy to find a good contractor. Or waterproofer. So, how do you know if you’re waterproofing is skimping on materials, width of drainage channels, etc. How do you know that if your waterproofer is not using 4” perforated, flexible coil, A.D.S. drain pipe, its normally a sign they lack the experience others have. In addition, if this were a new building, they would be violating new residential building code, and violating engineering standards. They are simply using a “gimmick” or “cookie-cutter” approach. License and franchise operations constantly do this, using box pipes with large holes, 2”-3” in diameter. They also constantly forfeit or dissolve their corporate structures because they believed the sales person who sold them the franchise, and told them that, “no, you don’t need any experience.” That was ok; No alarms went off; except when system failures started to mount up.

If your waterproofer is not installing 4” perforated drain pipe alongside the footing, below the level of the floor, but installing 2” or 3”on top of the footing, or using PVC plumbing pipe with drilled holes, or worse, putting the system right on top of or in the floor, they also lack the requisite experience or they’re simply using gimmicks. Again, if this were a new building, they would be violating new residential building code, and violating engineering standards. Pipe must be installed below the floor level, alongside the footing, but not below the footing, either outside or inside, these days, usually both.

If your waterproofer is wrapping the drain pipe in filter fabric and then using conventional gravel, they do not have enough experience, as experience will show this method to be ineffective. (see Gallery) All Filters Clog! This is why we change our oil filters, our coffee filters, our air filters, water filters, gas filters, AC filters, etc, etc. This is a fact. If drain pipes are wrapped with filters, they will fail within 3-5 years. If your waterproofer is not using round washed gravel, substituting crushed gravel, they don’t understand that crushed gravel is used for compaction, and round aggregate is used for drainage.

This is a $950,000 home in N.W. DC near River Road, bought in 2007, repaired by us in 2008. Outside drainage on their addition failed. Why? Drainpipe was wrapped with silt sock that clogged, which resulted in flooding of their substructure and deterioration of foundation.

For Peace of Mind, to get it right the first time, Call The Foundation Expert Today! Do overs are very costly when it comes to foundation repair and waterproofing.

Sump Pump and Battery Backup Systems

Zoeller Pumps have been around since 1939. The 1/3 HP works for 20-30 years. Zoeller gives a one year warranty, and any waterproofing contractor knows that they’re the best pump, plus they’re the best priced. Can’t be beat. Sump pumps remove water from one place to another, usually above ground, at grade. The water that has accumulated in a sump pit, reaches a certain level, and then the pump goes on, and discharges what was sitting in the sump pit; commonly found in the home basement, it is simply a hole or sump crock designed to collect water. The water may enter via the perimeter drain tiles or drainpipe of a basement waterproofing system, funneling into the pit, or may arrive because of rain or because of natural ground water, if the basement is below the water table level.

Older Sump pump systems discharge water away from a house to any place where it no longer presents a problem, such as a municipal storm drain or connected to the sanitary sewer, but this now goes against the municipal plumbing code, because it can overwhelm the municipal sewage treatment system or storm drain system. Sump pumps are usually hardwired into a home’s electrical system, and may have a battery backup. Some even use the home’s pressurized water supply to power the pump, eliminating the need for electricity. Since a sump pit may overflow if not constantly pumped, a backup system is important for cases when the main power is out for prolonged periods of time.

Pedestal Zoeller M53 1/3 HP Mighty Mate Sump basin 30” into the ground – very deep. Finished Product – Waterproofing Phase

There are generally two types of sump pumps: pedestal (which we do not use), and submersible. The pedestal pump’s motor is mounted above the pit, where it is more easily serviced but also more conspicuous and always in the way. The submersible pump is entirely mounted inside the pit, and is specially sealed to prevent electrical short circuits or tiny kittens, ducks, or anything from falling or accessing into the sump basin. These are what we install.

This sump pump method of removing water from around a home has been in use for over 80 years. It is sometimes the only way to remove water from around the house especially if it is a full in-ground basement. Sump pumps are also widely used where a daylight condition or gravity feed for the foundation drains is inaccessible. The most important thing in choosing a sump pump is the brand, the horsepower, the model, their failure history, all of which is important when determining how far the water must be pumped away from the house to effectively eliminate the threat of flooding. The number of pumps is critical. One for every basement up to 100 feet is the norm. 101 feet, two pumps. The size or Horse Power of the unit, the size of the sump basin, discharge, are important factors and should always be explained. Battery Backups for sumps are expensive, more than the pump installation including all materials for the sump. Back up Power Generators for the home start at $2000 now at home depot, a simple marine battery (deep cycle, and expensive) and simple electrical power unit to convert from 115 volt to battery power when the power goes out. $1000 minimum. Yes, expensive. The one’s they sell at Home Depot, we’ll put in, but no warranty if you want cheap. Battery backups can be your best and only option if you can’t afford a home generator. There are also gas generators that start at $300, which if someone is always around, then that can be helpful for all situations. Does someone always need, oxygen? Or to keep the weekend catch fresh? Or favorite wines and beers, foods, etc.? a generator of some sorts should be budgeted for.

Depending on your situation, we install a series of commercial-grade, cast-iron, submersible sump pumps made by Zoeller. We used to use a ½ HP, but in the last few years, every now and then, the ½ HP has failed. Despite repeated calls to Zoeller Corporate, they won’t spend the money to change the design and manufacturing. The 1/3 HP has always worked, usually as long as 35 years. Sometimes for outside solutions, we have to upgrade to ¾ , 2/3 or whatever is necessary to pump water if no gravity feed is available. Most sump pumps have a life span of 3 to 5 years. Zoeller’s last longer. Zoeller gives a one-year warranty. We guarantee our Zoeller pumps for 3 years because they usually last 12-15 years or more.

Whether you are replacing your existing system or installing a new system, we have the appliances necessary to keep the water flowing out and away.

Call The Foundation Expert if you need a professional evaluation, installation, and / or replacement of your pump.

Window Well Accessories

We offer a complete line of products and services to address just about any type of window well problem. Especially Egress Windows and Egress Window Wells.

If your window wells are overflowing, we can design and install a new drain system. If your window well liner is rusted or deformed, we can replace it. If your wells are uncovered, we also can install custom fit window well covers.

Sub Soil Drainage and Underground Extensions

Many homes are built on or near water tables, or simply have a property that does not drain during heavy rains; might be clay around the house always holding the water, not discharging. We are experts at sub-soil systems, dry wells, swales, berms, and other solutions to make sure your property and lawns drain properly. We also extend downspouts and sump pump discharge lines, which may deposit large volumes of water beside your foundation, which can lead to a number of different seepage and even structural problems but it must be done correctly by professionals and not by amateurs. It is good practice to divert as much surface water away from your foundation as possible. But eighty percent of the water around your foundation comes and fills up from the bottom up, not the top down, but filling up around your foundation with every inch of rain in your neighborhood, unless you’re at the top of a hill. Water constantly creates pressure, water / hydrostatic pressure.

Complete and Comprehensive Waterproofing Solutions
Water accumulation and the resulting cracks are the main concerns for all homeowners and commercial offices. At The Foundation Expert, we cater to all their needs. We offer dry basement waterproofing system and drainage sump pump installations in VA that provide the ultimate buffer against basement flooding, continuous water leaks and cracks. Our experience and expertise has propelled us to provide the best basement waterproofing services in Fairfax County through quick damage assessment, easy material procurement and restoration project completion well within the stipulated deadline.