Check our Basement Waterproofing Reviews on Angie's List

• 
  Wet Basement Causes & Solutions
• Causes & Solutions
• Understanding the Problem
• Structural Problems
• Basement Wall Damage
• Soil Moisture Changes
• Symptoms of Water
• Basement Moisture Problems

Apex Waterproofing

Your Waterproofing Experts!

Serving Maryand and surrounding areas

Welcome to Apex Waterproofing, your one stop shop for residential and commercial basement waterproofing and foundation structural concerns in Maryland. We are a fully licensed, bonded, and insured 3rd Generation General Contractor providing quality services to Maryland since 1943.

"It is estimated that 90% of all homes in Maryland will have basement water leaks in the first 25 years of their life.." WSSC (Washington Suburban Sanitary Commission) Report, Residential Drainage, Dealing with Wet Basements. Food for thought: In the Maryland the average age of a home is 35 years! How old is your home?

Basement Waterproofing in Maryland by Apex Waterproofing:

• 24/7 Emergency Service
• Superior Consultation & Expert Advice
• Financing available

• Highest Quality Product & Service
• Affordable Prices / 110% Price Guarantee!
• References & Testimonials Available

Our commitment is to provide you with 100% customer satisfaction through basement waterproofing and foundation repair innovation & experience, while providing cost effective solutions to your wet basement problems. We are the foundation waterproofing experts in Maryland!!

 

TESTIMONIALS

I highly recommend Louis Peyton and his Apex Waterproofing Company.  They did a professional and superb job fixing a ‘snap key’ hole on my basement wall today. As it turned out, after excavating to the ‘snap key’ hole, they noticed a fine hairline crack from the hole to the top of the soil line in the foundation.  This fine hairline crack was noticeable from the outside wall, and not much from the inside wall.  They waterproofed the hole and the hairline crack as well without extra charge.  After finishing the job, they did a great job replacing my plants, etc. back to their original state.  You would not know that an excavation had taken place at end of the day.  What professionals!

Another reason I recommend them is that Louis and his team were very patient and courteous in answering all my related concerns regarding water management of my basement.  They were very knowledgeable and were able to make other recommendations.

Sze-Ping Kuo
Columbia, Maryland

More testimonials ...

Save 5% - See How

Do you have questions regarding one or more of the following issues in your Maryland home:

• Water / dampness entering your basement
• Mold & Mildew and their associated insects, odors and dangers

• Wet or damp crawl space or cellar
• Structural issues, such as cracks or displaced walls in basement areas

Don't Wait Until It's Too Late. Call Apex Waterproofing today!

 

Egress Window Installation in Maryland

Basement Waterproofing in Maryland including but not limited to
Baltimore, Bethesda, Potomac, College Park, Hyattsville,
Chevy Chase, Silver Springs, Gaithersburg and more.

 

 

Basement Waterproofing Rising Ridge Rd, Bethesda, Maryland

 

Maryland Finished Basements and Waterproofing

Finishing your basement is a great way to add more space to your home. In older homes in Maryland, the basement was never intended as living space. Newer homes are built with the possibility of finishing the basements at a later date and are more waterproof than the older homes foundations. Moisture is the first thing that you will need to address if you are finishing your basement. The basement must be waterproof. Even a minimal amount of moisture can cause many problems in finished basements. Significant amounts of water will need to be addressed by a professional waterproofing contractor. Significant is actual pooling of water. Some minor basement water problems can be addresses by very simple fixes. Making sure that your yard grade is significant to drain water away from your foundation can help in a lot of cases. We specialize in basement waterproofing in Maryland.

 

How Your Foundation was Built

What is a Foundation

A foundation is a structure that transfers loads to the earth. The structure of something is how the parts of it relate to each other, how it was built. The age of your home can sometimes determine how your home was built and whether it even had a foundation to begin with. Is it 200 years old? Then it most certainly was built with stone, as opposed to more modern types of building materials such as terra cotta block in the late 1800's to early 1900's; cinder block, then concrete block, brick, pre-cast or cast-in-place (poured) cement, etc.; and, we find many homes which are 80-200 years old which were built without a footing or foundation upon which the walls rest. That determination is sometimes easy to make, sometimes only when the floor is opened up.

Foundations are designed to have an adequate load capacity with limited settlement - this is usually determined by a geotechnical engineer; the foundation itself is designed structurally by a structural engineer. The primary design concerns are settlement and load bearing capacity. When we consider settlement, we have total settlement, the entire structure settling as one total unit, and differential settlement. Differential settlement is when one part of a foundation settles more than another part. A footing crack in one part of the foundation would be considered differential settlement. This can cause problems to the structure the foundation is bearing or supporting. It is necessary that a foundation is not loaded beyond its bearing capacity or the foundation will "fail."

Other design considerations, especially in the MD geographical area, include scour and frost heave. Scour is when flowing water removes supporting soil from around a foundation, which may cause undermining and footing cracks. Frost heave occurs when water in the ground freezes to form ice lenses, which may cause footing and wall cracks. Frost action and heaving is a phenomenon that occurs in the winter and early springtime in Northern and Northeastern climates. Essentially, all surface soils undergo some frost action, the magnitude of which is dependent upon the climate and precipitation found in that geographic location.

 

Serving all of Maryland including but not limited to
Baltimore, Bethesda, Potomac, College Park, Hyattsville,
Chevy Chase, Silver Springs, Gaithersburg and more.

Basement Waterproofing and
Foundaton Repair Gallery

Potomac Maryland Basement Waterproofing

Frost Line, Soils, and Water

When construction takes place in a geographical area where temperatures reach freezing on a seasonal basis, such as our D.C. Metro area, a home's foundation must be built below the frost line; the frost line - also known as frost depth or freezing depth - is the depth at which the groundwater freezes. This is usually building code or if not, it should be to prevent substandard building practice and differential settlement. For example in Maryland, building code is certainly 30-36 inches below the surface, although the construction of a basement footing is much lower to accommodate ceiling heights of 6-10 feet or greater. If you have a walk-out basement, then the footing where the walk-out is located should also be 30-36 inches deeper than the threshold.

Bethesda Maryland Basement Waterproofing

Step Footing

If the site of the home is sloped, maintaining a constant elevation for the footings would either cause the footings to be above the frost line or significantly deeper than the frost line at one end of the building. Therefore, stepping the footings enables them to follow the slope of the site and remain below the frost line. Some soils are more susceptible to the formation of ice lenses than others are because they hold water as opposed to allowing water to drain. Silts or silty clay soils, such as those found throughout Maryland, Maryland and D.C. are considered amongst the most frost susceptible. Silts and clays - because of the extremely small size of their particles, or gradation - permit and encourage the flow of water by capillary action through its pores.

Capillary action (capillarity, capillary motion, or wicking) is the ability of a substance to draw another substance into it. Capillary action describes the attraction of water molecules to soil particles and describes the wick-like migration of water into the porous walls and floor in the same manner as water is drawn into a sponge. Capillary action is responsible for moving groundwater to the area surrounding your residence and then into your basement.

Consequently, silts and clays supply or hold the water necessary to the formation of ice lenses in the freezing zone. The only soils, which can be considered to be non-frost susceptible, are very clean mixtures of sand and gravel. These soils drain freely by gravity because there is nothing to hold or attract the moisture, and do not create capillary moisture movement. If your home were surrounded by sand and gravel you might never experience a basement water problem, as long as the foundation footing rested on a properly compacted soil, you did not have the high water table, which is endemic to our area, your home was constructed properly, and you had a properly installed foundation drain tile system.

In the Maryland area, eliminating the supply of water to the soil below the ground is virtually impossible, due to high water tables throughout the region, the constant rainfall, and the predominant clay soil. However, good or properly installed foundation and sub-soil drainage can partially reduce or minimize the quantity of water available to feed an ice lens and the cause of frost heave.

Changes in soil moisture can cause expansive clay to swell and shrink. This swelling can vary across the footing due to seasonal changes or the effects of vegetation removing moisture. The variation in swell can cause the soil to distort, cracking the structure over it. This is a particular problem for residential footings in Maryland, where wet winters and springs are followed by hot dry summers. The silty, loamy clays, which are predominant in our area, shrink and settle during the summer or dry months, and swell and expand during the fall, winter, and spring, causing walls and footings to crack, and basements to flood - whether the rainfall is torrential or normal.

 

Hyattsville Maryland Basement Waterproofing

Serving all of Maryland including but not limited to
Baltimore, Bethesda, Potomac, College Park, Hyattsville,
Chevy Chase, Silver Springs, Gaithersburg and more.

 

Excavation, Strata, Capillaries

The foundations of buildings are built on soil. Before homes are built, soil surveys are usually conducted with testing done to determine what soils exist, the water table depth, and whether the soil will bear the foundation weight. In commercial construction, usually compaction tests are part of the process of building the foundation. In residential construction, this is not usually done. The contractor simply abides by the architectural blue prints, which specify how the work is to be performed. Excavation is usually nothing more than digging out the ground where the home will be located, forming and then pouring the footings, and then building the walls and the rest of the home, usually as quickly as possible.

What you may or may not be aware of is this - before your home was built, that land probably sat there undisturbed for hundreds if not thousands of years (or hundreds of thousands of years), unless it was build on a landfill, which some communities in P.G. County are; that soil upon which your home rests, before it was built, was a conduit for all the watershed in the area directly above and adjacent to where your property rests.

Water has a few absolute characteristics: water has an excellent memory - if it followed a path once, it will seek that pathway again; water always seeks the path of least resistance (gravity - it moves downhill); water will seek its own level (self-balances or equalizes); and because it is the most powerful element on earth, it will go through or move ANYTHING in its path. It does not like to go around - talk with those in Louisiana and Mississippi. Sometimes it takes time before it will move something, but water does not recognize time. It has all the time in the world. This is why homes used to be built to stand for 100 to 200 years. These days, homes are falling down after 30-50 years or less.

In geology and related fields, a stratum (plural: strata) is a layer of rock or soil with internally consistent characteristics that distinguishes it from contiguous layers. Each layer is generally one of a number of parallel layers that lie one upon another, laid down and compressed, and then separated by natural forces. In between these strata are voids through which water migrates as water tables or capillary veins.

They extend over hundreds of thousands of square kilometers of the Earth's surface. Strata are typically seen as bands of different colored or differently structured material, which we see, exposed in cliffs and road cuts as we travel through mountain passes or by quarries and riverbanks. When planning civil engineering projects or other large construction projects, the strata of the area where the construction takes place is a significant factor in design decisions. For example if a canal is to be built on a route where the strata are not watertight, the canal will have to be lined with some form of waterproof material.

Situating a home on top of a hill is always more prudent than in an area which is in a valley. As ground water seeps into the deeper strata of the surrounding soil, it characteristically follows the natural slope or grade of the surrounding area - it moves downhill! First, the topsoil will absorb some of the water. Although water runs on the surface, most water is actually migrating quite slowly through the ground, between the strata. As the water first hits the surface as rainwater, it slowly soaks into the ground, until the ground is saturated.

When this happens, we then have flooding conditions. When the ground can no longer absorb a torrential downpour, the rain becomes surface water, and this water runs quickly into the surrounding roadways and streets and enters the municipal storm drains, which are rapidly overwhelmed and subsequently back up. The result is flooding and flash floods. Think about this - all water which falls east of the Appalachian Mountains, finds its way into the Atlantic Ocean by way of surface and sub-surface water ways, rivers, creeks, streams, water tables, and capillary veins.

Because your home is surrounded by looser backfilled soil, which probably was not compacted, it will always be more absorbent than the virgin soil surrounding it. This means that you will have an artificial water table around the home where, in most cases, more water will collect than anywhere in the area. This is sometimes called the "clay bowl effect" by waterproofing companies, since your house in essence, sits in a bowl of dense clay.

As moisture builds up in this area around your home, it creates hydrostatic pressure against the floor first, and as it rises above the floor, against the basement and foundation walls. This pressure can lift the floor, damage the walls as moisture presses on and searches for the path of least resistance, or any way to pass through the basement wall and floor cracks as well as through the cove area or where the basement wall meets the basement floor. This moisture, either in liquid or in vapor, will also wick through porous concrete, mortar, concrete block, and grout.

Foundation Types

In general, foundation engineering applies the knowledge of geology, soil mechanics, rock mechanics, concrete, steel and structural engineering to the design and construction of foundations for building and other structures. The most basic aspect of foundation engineering deals with the selection of the type of foundation, such as using a shallow or deep foundation system. Foundations are commonly divided into two categories: shallow and deep foundations.

 

Bethesda Maryland Basement Waterproofing

Shallow and Deep Foundation

Deep foundations, usually designed for commercial buildings, which have multiple stories, are used to transfer a load from a structure through an upper weak layer of soil down to a stronger deeper layer of soil such as bedrock. There are varieties of deep foundations including caissons, piers, piles, drilled shafts, and earth stabilized columns. The naming conventions for different types of foundations vary between different engineers. (We will only concern ourselves with shallow foundations, as this is 'Understanding Residential Construction.')

A shallow foundation is a type of foundation, which transfers building loads to the earth very near the surface, rather than to a much deeper subsurface layer, or a range of depths as does a deep foundation. Common Types of Shallow Foundations:

• Spread Footings - also called pad footings are often square, are of uniform reinforced concrete thickness, and are used to support a single column load located directly in the center of the footing.
• Strip Footings - (very similar to spread) also called wall footings are often used for load-bearing walls. They are usually long reinforced concrete members of uniform width and shallow depth.
• Combined Footings - reinforced-concrete combined footings are often rectangular or trapezoidal and carry more than one column load.
• Conventional Slab-on-Grade - a continuous reinforced-concrete foundation consisting of bearing wall footings and a slab-on-grade. Concrete reinforcement often consists of steel rebar in the footings and wire mesh in the concrete slab.

Spread footing foundations are common in residential construction that includes a basement, and in many commercial structures.

 

Maryland Basement Waterproofing

Serving all of Maryland including but not limited to
Baltimore, Bethesda, Potomac, College Park, Hyattsville,
Chevy Chase, Silver Springs, Gaithersburg and more.

 

 

Mat-slab foundation
Slab-on-grade foundation

Pictured here is a 21-inch thick reinforced concrete mat slab foundation - so called because it underlies the entire building as a continuous thick mat rather than as a series of separate piers and footings. Mat-slab foundations are used to distribute heavy column and wall loads across the entire building area, to lower the contact pressure compared to conventional spread footings. In high-rise buildings, mat-slab foundations can be several meters thick, with extensive reinforcing to ensure relatively uniform load transfer.

Footings

Footings are generally made of concrete with steel reinforcement. Most residential footings are between 16"-24" wide and 8"-12" thick. The width of the footing helps spread the weight of the house to prevent excessive settlement. Steel reinforcing bar (also called rebar) is run horizontally through the footing for added strength. The rebar is overlapped and tied together. "L" shaped rebar is placed vertically into the footing after the concrete is poured with about 2' sticking above (see picture above). This rebar strengthens the connection between the foundation walls and the footings.

The footings are usually formed with 2 x 8 or 2 x 10 boards (laid on edge) and held together with stakes on each side and straps or longer stakes across the top. Once the footings are connected, they are set to grade with a laser level or transit. Setting the footings to grade is the process of leveling them. If the footings are not set to the same height, the house will not be level (flat). After the footings are formed and reinforcement placed they are inspected by the building Inspector. The footings are poured and the concrete is allowed to cure - some builders wait a day, some wait 7 days or longer. The forms are then removed and usually reused on another job.

Walls

Now it is time to build our walls. Every week or so, we will conduct a home inspection where the home was built with stone, brick (very common in D.C.), or terra-cotta block (pictured below). Modern day construction uses pre-cast or cast-in-place concrete, or concrete block, sometimes referred to as cinder block, or concrete masonry units.

Bethesda Maryland Basement Waterproofing

Cast-in-Place / Poured Concrete Walls

When concrete walls are poured, they need time to set-up and cure. However, in today's world, time is money and home builders only have to build to code, which is a minimum standard. Concrete can take ten years or more to fully cure, taking into consideration factors such as the mixture and preparation of the concrete, the humidity level of the air, and the temperature of both the concrete and the outside air during construction. As a result, the foundation is usually built before the concrete is fully ready to withstand the load.

As concrete is mixed and poured into forms, vibrating rods are inserted into the mixture to eliminate air bubbles. This is often done improperly or too quickly, allowing air bubbles to remain, which weakens the concrete walls. Air bubbles will expand and cool at different rates than the concrete around it, causing deterioration and cracking. Another factor is too much water in the mix can also weaken the concrete and subject it to early spalling. Spalling is defined as the flaking of bricks, concrete, or stone through deterioration, usually as a result of frost, chemical action, or the movement of a building structure.

Concrete Block Walls

Concrete block or a Concrete Masonry Unit (CMU) is made from poured concrete. The primary ingredients are Portland cement, gravel and sand, the same ingredients in poured concrete. The difference is the size of the gravel used in either application. Typically, you will see gravel as large as three-quarter inch diameter in poured concrete, whereas the gravel in block is usually pea gravel, no larger than the size of a pea. Most blocks measure to 8" although the standard units are actually 7-5/8" in width. This allows for the thickness of the mortar on the finished job.

Building exact corners is the critical component of a Concrete Masonry wall, since the corners will be the guide for the rest of the wall. Before you lay your first course, you will spread mortar about 1" thick on the footing to anchor the first course of block. Once the corner blocks are placed, the lead blocks are set. This will entail about three or four blocks going from each side of the corner like a pyramid.

Then, the first course of block is laid from corner to corner, allowing for openings or doorways. Mortar for these blocks is spread on all vertical edges of the block before the block is carefully put in place. When laying the second row or course of block (and all rows above), mortar must also be placed on block directly beneath the block to be laid.

Each course of block should be staggered so the block being laid is placed half over one block below and half over the other block below, or however the hollow cores line up, as long as each course is staggered as illustrated above. When concrete blocks are stacked on top of one another, similar to Legos, you can look down through the hollow core centers of each block. After the concrete blocks are laid, the hollow cores can be filled with a cement-based mortar, grout, or poured concrete that contains small pea gravel. If the builder does this (rarely encountered due to the added cost), then the filled concrete block walls are nearly identical in strength to poured concrete walls.

In order to have a strong wall, reinforced steel bars (rebar) are placed within the forms or within the hollow cores. Often you will see horizontal steel bars placed in the lower and upper sections of poured foundation walls. This steel usually has a tensile strength of 40,000 pounds per square inch. The rebar helps prevent vertical cracks should the foundation drop or heave. Horizontal wire reinforcement is also placed in the mortar joints between layers of concrete block to achieve the same result.

Waterproofing Walls to Code

Once your walls are completed, neither wall system will be waterproof. In order to pass inspection, the builder will spray a waterproof tar coating over a concrete wall, or will parge a block wall first. Parging (pargeting) is simply applying a coat or two of mortar over the block to create a contiguous surface, which can then be waterproofed, the block being too porous as is. The typical parge coat is 1/32"-1/16" in thickness. Once parged, the builder will then apply or spray the tar onto the parge coat.

In the old days, tar was applied with brushes straight out of the bucket, towed by trucks, which heated the ingots or pigs of tar for ease of application. Today we have machines, which spray the tar, again paying attention to cost, as opposed to quality. Some custom home builders at this point actually install sophisticated waterproofing systems, incorporating membranes, advanced rubber liquids (as opposed to tar), drainage mats, and other innovative systems which are readily available, but cost much more than 'builder grade.'

 

Bethesda Maryland Basement Waterproofing

Maryland Basement Waterproofing

Drainage and Drain Tile

Next, because it is code, and should be done regardless, a drain tile system needs to be installed directly adjacent to the footer, never below the footer, and never above, where the bottom of the floor will be. Although drain tile should also be laid outside the foundation walls, again adjacent to the footer, building code in Maryland now dictates inside drain tile leading to gravity (rare) or, in most cases, a sump pit and pump. Again, some custom or quality homebuilders will do both - interior and exterior. Regardless, whether it is located inside or out, the drain tile should be totally surrounded with a bed of washed gravel, and sloped 1" for every 10' - 20', two other design specifications, which are usually ignored.

This is a great example of the proper way to waterproof a new exterior foundation wall. Notice that the gravel comes almost to the top of the excavation. The wall is sheathed in drain mat which will not allow any water to sit against the wall, acting not only as a vapor and waterproof barrier, but a wall drainage system so that water drains down the wall into the drain tile, which is located below the gravel next to the footing.

Pouring the Floor

Once the foundation walls are laid, the floor is poured. To do this, a blanket or layer of gravel is laid down, usually crushed blue stone #57, between the walls, and over top of the drain tile, which is next to the footings and the dirt. A cross-laminated polyethylene vapor barrier anywhere from 6-12 mils in thickness is then laid over top of the gravel. Next, rebar and reinforcing wire are laid out in grid like patterns, and the concrete is then poured to create a 4" thick floor slab, some builders installing an expansion joint around the perimeter, most just allowing the floor to shrink somewhat as it cures and loses moisture. In the past, when concrete was inexpensive, a few custom homebuilders poured floors which were anywhere from 6" to 12" thick. Code is 4" which is usually adequate.

Monolithic Foundations

In some older homes, the foundation and floor were poured as one complete unit, called a monolithic pour or foundation, constituting or acting as a single, rigid, uniform whole. The walls were then formed and poured, or built on top of the floor slab. In this instance, drain tile could have only been installed outside, as inside, or under the floor would have no benefit, as the only way moisture can penetrate this type of foundation would be through the wall or under the wall.

Monolithic Foundation

Backfill

Once the walls are built and waterproofed, and the drain tile is placed next to the footing, the excavated soil (known as "backfill") is usually added back into the empty space surrounding the walls. Waterproofing, wall cracks, and various structural problems in Maryland are sometimes a direct result of the soil, which was placed in the backfill when the house was built. Current building code mandates that backfill consist of more than 50% sand and stone aggregate, but that isn't always a code that is followed.

In any case, when the backfill takes place, the curing cement foundation walls are shocked by the backfilled soil in three different ways: temperature, weight/pressure, and impact. The soil pressing against the concrete can cause it to either shrink or expand with the change in temperature; the sudden weight of the backfilled soil, which adds sudden pressure to the walls, can be detrimental to the slowly curing cement and structure. In addition, builders traditionally throw all of their trash back into this void around the house, and as the soil, rocks, and debris are backfilled into this space - sometimes hastily or carelessly - this can also cause damage to the walls.

In addition, during the construction phase, the foundation walls are generally exposed to variations in weather conditions, such as rain, heat, freezing cold, and humidity. All these factors can cause future problems with basements and foundation walls, which you are maybe now experiencing. (See Causes and Solutions)

 

Save 5% - See How

Lou@apexwaterproofing.com

APEX WATERPROOFING INC
NATIONAL HARBOR MARYLAND 20745
301-684-3896
800-656-4604

 

Bethesda Maryland Basement Waterproofing
Gallery

 

Baltimore Maryland Basement Waterproofing

 

basement waterproofing
basement foundation waterproofing
basement wall waterproofing
basement waterproofing companies
basement waterproofing company
basement waterproofing contractor
basement waterproofing contractors
basement waterproofing repair
basement waterproofing service
basement waterproofing services

basement waterproofing systems
exterior basement waterproofing
interior basement waterproofing

outside basement waterproofing
wet basement waterproofing

 

 

RESOURCES