Swimming pools need care even in the winter.

An above ground swimming pool can bring us years of enjoyment as long as we take care of it in a responsible manner. The frigid, freezing temperatures of winter are the most ruthless adversaries to the pool and it’s equipment, so winterizing your above ground pool is essential if you have plans to use it again next summer.

The first, and perhaps most important step before you put your pool to bed, is to make sure the chemical balance of your water is correct. If it isn’t, corrosion or scale buildup might occur while the pool is shut down.

There are four basic water content levels that need to be checked:

• The pH should be between 7.2 – 7.6.

• Alkalinity should be 80 – 120 parts per million.

• The chlorine content should be 1 – 3 parts per million.

• The calcium hardness should be 175 – 250 parts per million.

All of these tests can be performed by purchasing a good test kits from your local pool supply store. Just follow the instructions and adjust the content accordingly.

The sides and floor of the pool need to be brushed down and vacuumed. If any kind of dirt or other foreign matter is left in the pool, stains might penetrate their way into the pool lining.  While you’re at it, don’t forget to add winterizing chemicals in the deep end. This will protect the water quality.

Your skimmer, filter and pump basket should be cleaned along with the cartridge filter elements and Diatomaceous Earth (D.E.) filter grids. Any sand filter you may have needs to be back-washed. Take your chlorinator and remove any remaining tablets from it. If these tablets are left in it, they could end up staining or bleaching your pool liner over the winter months, especially if the floater winds up resting against the side of the pool wall.

Check your filter tank, pump and other critical equipment for drain plugs. If you find them, go ahead and remove them to drain them of water. One additional thing you need to do after this is turn the pump on for just a few seconds so the impeller will blow any remaining water out of it. This will help protect your pump from being damaged when the water freezes. Place your drain plugs with your other stored equipment.

Depending on your personal preference, either drain the pool until the water level is below the water jets and skimmer, or insert a pool skimmer guard into the skimmer itself to protect it from damage when the water freezes. Freezing water will expand and damage or burst any piping that’s associated with your pool.

Place an air pillow in the center of the pool and tie it to the pool walls with a strong string. If the water freezes, it will expand toward the pillow rather than toward the pool walls. Were the water to expand toward the pool walls, the resulting pressure could end up bursting the side walls, and you’d end up with a real mess, not to mention a hefty repair tag to go along with it.

Cover the pool with a winter cover and secure it tightly so it won’t come off.

By following these procedures your pool should survive even the most brutal winter mother nature can throw at it. Be sure to double check the documentation of all your pool devices to be sure you’ve stored everything properly per their instructions.

For more articles by this author, go to Helium.

Expansive Cracking
Common in large structures, expansive or “thermal” cracking is an issue. Temperature differences between concrete surfaces and interior can cause frequent expansion and contraction of those areas which will result in cracking from the stresses. Huge temperature differences can cause some pretty significant cracks, so contractors prepare for this by the use of internal reinforcements and strategic placement of expansion joints to allow some movement. When necessary, cracks of this type can usually be repaired with a specially designed repair product like epoxy. Similar are the cracks that occur in climates with freeze-thaw cycles. When the ground surface freezes, it expands and can cause heaving of whatever is on top of it, usually your driveway, sidewalk, etc. Again, in addition to proper use of interior reinforcements and strategic joints, contractors also have to prepare the surface on which the concrete is going to be poured to best alleviate the effects of heaving. This may include but is not limited to several inches of packed stone.

Shrinkage Cracking
Extremely common in most concrete is “shrinkage” cracking which occurs during the curing (drying) process. Cement uses water as part of a chemical reaction causing it to harden. Excess water actually dries and like many items, concrete can shrink as the excess moisture disappears. Since the surface usually dries faster, it shrinks more than the rest. The shrinking can cause stress, with enough stress, cracks can appear. These tend to be purely aesthetic and many contractors will assure customers that they will do all they can to prevent them; if they do happen, do not worry about serious problems. One form of crack prevention comes in the form of control joints. They serve two purposes. They provide start and stop points for the shrinking and provide a slightly weaker point in the concrete which will induce cracks as needed from expansive stresses. Other prevention measures are careful control of the water content of the concrete mix. Excess water is bad, but often happens because it makes the concrete easier to work with. Dry concrete just does not go down well, so water content often ends up somewhere in the middle. This excess water can also contribute to “spalling” which is the small divots and flaking you find on a concrete surface. In addition to water, simply making sure the concrete mix is designed for the job is also important. Subtle differences in the mix design will allow it to be used more easily for the job at hand such as the inclusion of air, set retarders, accelerators, fibers, etc.

Regardless of preventive measures, Mother Nature is a tough opponent and will often come out winning. As a customer, you may now understand why even the most experienced contractor avoids warranties against cracking. As a contractor, making that guarantee is sort of like a die hard Cubs fan guaranteeing a World Series victory. Despite all the off-season preparation, come fall you are going to be let down.

Remember, if both parties involved have a good understanding of the nature of concrete and why the unexpected may occur, it will help alleviate some of the stress if it becomes an issue.

Article by Don Ciesielski and courtesy of Contractor Source.

Most people prefer to make use of salt to de-ice their driveway. Salt, or sodium chloride as it is also known, has been used for many years, and is often just sprinkled over the driveway to remove ice. There is though a cost involved, despite it being one of the cheapest options. Salt will work fairly fast in removing ice, but can cause damage to the driveway, as well as to the metal of any car that drives over it. Additionally salt will harm plants as it prevents them absorbing nutrients and moisture. Salt will only work when the temperature is in excess of 18 degrees Fahrenheit.

There are other chemicals available which will do a similar job to salt. Of these others the most common are Potassium Chloride, though this will also harm plants and is slower working that salt. Additionally Potassium Chloride only works when the temperature is above 25 degrees Fahrenheit.

Faster working is Calcium Chloride and Magnesium Chloride. Calcium Chloride will harm concrete and plants alike, whilst Magnesium Chloride will also harm plant life. All of the chemicals do remove ice from driveways, but there is a cost often to the driveway and the environment, and ice can reform fairly quickly if temperatures continue to rise and fall.

The old methods are still the best and shoveling snow and ice is the best for the environment and the driveway surface. If thick ice has been allowed to build u,p then a shovel is not the best tool to break it up. Many stores now sell ice chippers, tools which will break up ice, allowing them to be shoveled away. Care needs to be taken when using shovels and ice chippers, as too much force could see the driveway damaged.

Having cleared away the ice, then it is best to add some sand to the driveway. Sand itself will not do anything to the ice but will aide traction for both cars and pedestrians.

Removing ice from driveways is a chore but it is a necessity come wintertime. There are a number of options available to remove the build-up of ice but there is a price with each.

Written by Tim Harry. Find more articles by this author at Helium.

Benefits of Electrical Underfloor Heating
The principle advantage of electrical underfloor heating is that it is energy efficient. If installed in a room with adequate insulation, an electrical underfloor heating system can provide the same level of comfort as a traditional radiator system, but at an air temperature 3 or 5 degrees F lower. Traditional radiator systems heat the surrounding air, which rises to heat the space below the ceiling of a room first, whereas electrical underfloor heating systems heat the entire surface of the floor first. This creates a more comfortable temperature gradient, with an even distribution of heat and no hot or cold spots.

Not only that, but the increased efficiency of underfloor heating means that you can save anything up to 20% on your domestic fuel bills and, in turn, reduce your carbon footprint. Traditional radiator systems can also create convection currents in the air, which circulate dust and other allergens, so underfloor heating can be beneficial to sufferers of asthma and other respiratory ailments.

Of course, underfloor heating is also effectively invisible, so there are no unsightly radiators or pipes to interfere with the interior design of a room. Electrical underfloor heating is also cost effective and can be installed by a reasonably competent DIY enthusiast.

Floor Coverings
Underfloor heating obviously relies on thermal conduction, so materials with high thermal conductivity, such as natural stone, ceramic, etc. are ideal for use as floor coverings. That said, however, electrical underfloor heating cables, mats and films are available in a range of output wattages, to suit a range of environments and floor coverings. An area of high heat loss such as a conservatory may require an output of 150 or 200 W/m2 (“Watts per square meter”), but underfloor heating elements with lower outputs, suitable for installation beneath laminated wood, vinyl, carpet, etc., are also available. It is, of course, important to abide by manufacturers’ guidelines with regard to both heating elements and floor coverings.

For more information on heated under floors, please go to Hot Floors.

As a licensed professional engineer, I am called in to evaluate cracked foundation walls frequently. Unfortunately, repairs for defective foundation walls can easily cost tens of thousands of dollars. However, much money can also be wasted based on incorrect evaluation by unqualified persons.

Water in the soil around a basement is often one of the factors responsible for cracked foundation walls. Water in the soil may also be the source of water leaking into a basement. However, cracks in foundation walls are generally not the primary cause of water leaks. There are also other potential causes of water infiltration into a basement. Therefore, although increased pressure from water (against foundation walls) is relative to this discussion, the topics of water infiltration (leaks) into a basement and waterproofing should be discussed separately.

Much information provided online about this topic (cracked foundation walls) is grossly misleading or totally incorrect. Many descriptions tend to be vague, confusing or off-topic. Examples of incorrect online information are provided at the end of this discussion.

DISCOVERY OF FOUNDATION CRACKS
Cracks in foundation walls typically occur within several years after a house is built, although there are exceptions (such as tree roots). Owners often do not notice cracks until many years after initial formation. This is especially the case in dark basements. The most dangerous situation is when cracks occur in foundation walls when the basement is finished. Although catastrophic failures are relatively rare, cracked-wall conditions can progress over time to total foundation wall failure without anyone seeing the progression.

Cracks in foundation walls often become a major issue when discovered by a home inspector during a pre-purchase inspection. Although the owner usually contends a cracked wall has been that way “forever”, a buyer tends to become concerned when confronted with a warning in the inspection report. Homeowners selling a house often attempt to cover-up foundation cracks by painting the wall or filling cracks with flexible caulking. A qualified, experienced home inspector should highlight any such attempt in the home inspection report.

BASIC TYPES AND CAUSES OF CRACKS
Cracks are generally considered vertical, horizontal or “diagonal” (sloped), even though most cracked-wall conditions include all three categories.

Narrow vertical cracks are most often caused by minor settlement or normal shrinkage. Such cracks are not structural defects. Wide vertical cracks (such that the thickness of a 25-cent quarter coin can be inserted) may be caused by significant settlement problems that require detailed engineering inspection and evaluation. In concrete walls, you will almost always find numerous, very narrow (“hairline”) vertical cracks. These cracks are caused by normal shrinkage of concrete and are not a structural defect. Foundation walls built with concrete block (often, and incorrectly, described as “cinder” block) are much more likely to be cracked than solid concrete walls, especially if the block wall is constructed of 8-inch block.

Horizontal cracks are much more of a concern than vertical cracks, especially in block foundation walls. Foundation walls must of course support the vertical weight of a building. Foundation walls around a full basement must also resist inward (lateral) pressure from soil against the wall. If soil (backfill) becomes saturated with water, inward pressure can easily overload a block wall, resulting in cracks. Excessive inward lateral pressure against a block foundation wall all too often causes horizontal cracks in mortar joints. Telltale sign of excessive lateral soil pressure is a horizontal crack, about mid-height of the wall. Towards the ends of a straight foundation wall segment (near corners), horizontal cracks transition into “step” cracks, which are short vertical and horizontal cracks.

The building code includes standard limits for height of “unbalanced” backfill soil against a concrete block or plain concrete foundation wall. For an 8-inch hollow concrete block wall, height of backfill (above basement floor slab) is limited to 4 feet. Block foundation walls often remain cracked for many years without any obvious additional cracking or inward movement (bulging). However, once a horizontal crack occurs, the structural integrity of the wall is greatly reduced. If soil backfill becomes saturated during periods of heavy rainfall, cracks can increase or, in the worst case, the entire foundation wall can collapse into the basement.

Roots from large or even moderate size trees near a foundation wall can easily cause major problems with block foundation walls. Roots tend to grow towards foundation walls because water accumulates along the wall.

BASIC REPAIR METHODS – HORIZONTAL CRACKS
Cracked foundation walls can be permanently repaired, without complete replacement, as long as inward movement is not excessive, even though evaluation of excessive movement is somewhat subjective. The key issue is whether the wall can continue to provide vertical support for the house without risk of severe damage in the even vertical loads are increased. Inward movement is typically measured relative to base of wall, using four-foot carpenter level or plumb string-line. Maximum inward movement (deflection) usually occurs at the horizontal crack and near mid-height of the wall.

If inward movement of a cracked foundation wall exceeds 1-1/2 inches, or if a hinge has occurred at the horizontal crack, consideration must be given to complete replacement of the wall. Cost for replacement is typically much greater than cost of bracing. Therefore, having repair work performed before inward movement increases is essential to minimizing repair costs. Traditional repair methods involve bracing the foundation wall with steel post-braces or reinforced block piers. Steel post-braces may be less expensive than piers, which must be placed on a concrete foundation (footing). However, piers often provide a better finished appearance.

Steel post braces must be securely connected at base and top, which is all too often neglected if braces are not designed by a qualified engineer. Steel reinforcing bars have successfully been installed (grouted) into block walls to provide adequate strength to resist soil pressure. However, this method is highly dependent on quality of workmanship. Inspection is effectively impossible once bars are in the wall. Installation of bars also requires extensive removal of inside face of block wall, which can cause damage to unseen parts of the block.

In recent years, more exotic repair methods have been developed, such as tiebacks and carbon-fiber strips. Although these methods have been used successfully, there have also been failures, as there are with any relatively new technology. Careful application of newer methods is therefore warranted.

MISLEADING AND INCORRECT ONLINE INFORMATION
Examples of errors with online information, discussed below, demonstrate why it is important to obtain information about foundation wall problems from qualified professional engineers.

INSPECTAPEDIA
Currently (10-18-09) the top link obtained from a Google search of “cracked foundation wall” is an advertisement for inspection services on the “InspectAPedia” web site.

http://www.inspect-ny.com/structure/FoundationCracks.htm
Excerpts from a “book” (that apparently is not available other than online) provide some detailed information about evaluating cracked foundation walls. At end of the web page, the apparent author (Daniel Friedman) includes a long list of persons without any clear description as to the intent. The apparent intent is that these persons are contributors or perhaps fact-checkers.
Statement of qualifications notes that Mr. Friedman is an “Educator, author, Building failures researcher” and a “Consultant specializing in construction & environmental testing & inspection.”

Although much information presented is valid and useful, some claims are confusing and misleading, as noted with the following two examples:
(1) Claim that the location (within height of wall) of horizontal cracks explains the reason for the cracks are overblown. This claim is simply not reasonable considering the wide variety of factors that can result in horizontal cracks, including workmanship, materials, and various sources of loads over long periods of time. One major source of cracks (tree roots) is completely ignored.

(2) A diagram included with “Repair Methods for Bulged Foundation Walls” is grossly incorrect. Base of the vertical steel channel is shown above the floor slab, without any connection. This is a major mistake. Base of any such vertical brace must have secure connection to the floor slab to resist horizontal force, which is greatest at base of the brace.

ASK THE BUILDER
An example of misleading and incorrect information that you might trip over online (as of 10-18-09) is the following from the “Ask The Builder” web site:

Crack Appearance: Horizontal Crack in a foundation wall. Commonly seen in concrete block walls. Crack is usually 4 to 5 feet off the floor.

Possible Cause: Poorly designed foundation wall. Wall is actually a retaining wall trying to hold back dirt from falling into basement. Can be fixed with beams or helical piers.

Description of the crack is not complete since horizontal cracks in block walls always occur in one or more horizontal mortar joints. Comment about “usually 4 or 5 feet off the floor” is not correct. Most horizontal cracks occur at or below mid-height of a block foundation wall, where the largest flexural tension stress occurs. The vast majority of residential block foundation walls are less than 8 feet high, such that height of horizontal cracks is generally less than 4 feet above basement floor slab.

Horizontal cracks can be caused by defective construction as well as defective design. While the “retaining wall” comment is correct and useful for understanding, this is true of any foundation wall, not just a wall with a horizontal crack. Most important however is that the suggested repair methods (“beams or helical piers”) are grossly inadequate and incorrect. A beam is generally a horizontal element. A foundation wall with horizontal cracks must be braced with vertical elements, against the wall. “Helical piers” (a type of steel pile) are used only to underpin a foundation wall when settlement (downward movement) is the problem. Helical piers (also known as “auger piles”) are not useful in any way to repair a foundation wall that has been cracked due to inward soil pressure.

For more articles by this author, please go to Helium.com

John F Mann, PE
Structural Support
1212 Main Street, Suite 2
Belmar NJ 07719
732-556-6080
jmann77@optonline.net

The following tips will help you in your quest for a drier basement.

EVALUATE THE SOURCE OF THE MOISTURE:
In order to get rid of basement moisture, you need to first identify where it comes from. The following are common sources of basement moisture.

Inadequate drainage: If you get puddles on the floor during heavy rainstorms, your moisture at least partially comes from inadequate drainage around your house.

Moisture released through the foundation: Many new foundations are sealed with a moisture on the outside of the foundation wall, but older brick and cinder-block foundations can absorb moisture from the ground and release it into your basement.

High water table: Areas prone to flooding, like those near rivers, often have higher water tables that can rise after heavy rains, causing your basement to fill with water.

Human-generated sources: Venting a dryer indoors, basement showers, or windows that let in humid air are all easy-to-remedy sources of excess moisture in basements.

TACKLE POTENTIAL SOURCES FROM BIGGEST TO SMALLEST:
The biggest source of basement moisture is often inadequate drainage. First, check your gutter system: are the downspouts emptying at the base of the foundation? A significant amount of water is collected off the roof of a home during a rainstorm, and you don’t want to dump all this water right where it can leach into your basement. Even if the ground slopes away from the house, you want to extend the downspout at least three to four feet away from the foundation wall.

Ideally, your property should slope away from your foundation walls on all sides. If your house is built into the side of a hill, however, this may not be an option. The trick is to collect any surface water before it actually reaches your house. Drainage ditches will often do the trick; just make sure they have enough slope to actually carry the water around the house and away. If the water is already being channeled to a particular spot (like down a path,) consider installing a drain and pvc pipe to carry the water safely away from the house.

Now that you have gotten rid of a major source of moisture, it is time to tackle the basement walls. Moisture that comes through old brick or cinder-block walls is not always obvious. (In fact, obvious moisture may actually be condensation from dryer vents or humid outside air.) Your walls may feel a bit damp, or there may be slightly darker spots in certain areas.

If you suspect moisture is coming through your walls (and ESPECIALLY if you plan on sheetrocking,) buy a good waterproofing masonry paint like DryLoc. These paints are designed to seal up the pores of masonry surfaces and block water from getting through.

High water tables can prove one of the more difficult challenges when it comes to keeping your basement dry. Sump pumps and french drains (perforated pipes in a bed of gravel) installed under the floor may be needed, depending on the severity of the water problem. Depending on the particular situation, this can be an involved and expensive process. Fortunately, high water tables only pose an occasion issue for most home owners. If you have no intention of finishing your basement, sump pumps will often be adequate to deal with occasional flooding due to high water tables.

Eliminate easily-controlled moisture problems by venting dryers and bathrooms to the outside. During hot, humid days, keep basement windows closed. Don’t hang clothes to dry in your basement, and make sure any leaky plumbing is repaired. Automatic dehumidifiers can remove remaining moisture, but the tank will have to be emptied every few days. If you can somehow route a garden hose outside your basement, perhaps by drilling a hole through a window molding, there are dehumidifiers that can drain through a hose, eliminating the need to empty the tank. (Just remember, the hose will need to slope downhill for this to work. You may need to place your dehumidifier on a high shelf to accomplish this.)

Even if you have no plans for finishing your basement, using these tips to create a drier basement will be good for your health, the longevity of your home itself, and will make the basement a safer place to store things or set up a small work area.

I have been in a number of homes recently with wet basements. This always happens more when we have a lot of rain. This is actually a good thing, since buyers are more likely to see if there are water issues in a home and make a more informed decision.

Many times a wet basement is the result of a plugged drain outside a walk-up basement, or the failure of a sump pump. In other cases it may be the result of improper grading around the house, causing water to pool at the foundation which is then forced into the house. These are all fixable problems.

The important thing is to know the source of the water in the basement before buying – or putting your home on the market to sell! If you have water in your house, I recommend you consult a qualified home inspector or landscaper to address drainage. There are companies that specialize in installing elaborate drainage systems in basements, but my view is that these are overkill and rarely justified.

Let’s talk about mold. If there is a persistent moisture problem you may find there’s a mold problem. Some of my buyers want a special inspection for mold, but the experts I’ve talked to say unless you see the mold, you don’t have it. The sure signs are water stains along the lower part of basement walls and black splotches. You may also smell mildew. If you have mold you need professional treatment, and it can be expensive. But it’s a health problem and must be dealt with.

Hopefully we’ll start having more dry days than wet and we can enjoy our nice, warm, sunny Virginia summer.

Written by Craig Lilly as found in Craig Lilly’s Newsletter.

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