Thursday, July 5, 2007

Keeping basement dry - Gutters

As rainwater rolls off your roof and into your gutters, it's then channelled to flow toward the nearest downspout and safely away from your home.

By having clogged rain gutters due to leaves, sticks, and other debris, the rainwater simply overflows the gutter and pools at your home's foundation.

To combat this from happening, and to keep your basement dry, be sure your drainage system is working properly. Clean gutters and downspouts on an annual basis to be sure water flows through.

Check to be sure there are no cracks in your guttering which allows water to seep down the side of the house.

If you do see a problem with your gutters and downspouts, take care of it as soon as possible. If you don't feel comfortable doing the work yourself, call a gutter company to come. The rates are more than reasonable and well worth the protection from future damage.

Keeping your basement dry begins with rain gutters that are working properly. It may be all you need to keep it that way.

Basement design matters the most !

I have been working around various techniques in this regard experiementing some of my own and also finding various techniques found on the Internet for the best basement design.

Basement design is the most important thing with regards to basement waterproofing.
Whoever would think that it was possible to make a basement design that would turn a dark and dirty concrete basement into a beautifully finished living room? Well, who ever thought even about the very idea of living under the ground? Most people would say that living under the ground is for cavemen and primitive undeveloped cultures, but in today’s ever increasing verticalized towering urban landscapes and cities, nothing could be more efficient and modern than a good basement design and that makes proper use of all possible living space in a home.
Thousands of years ago in what is now Turkey, the ancient Hittite civilization had constructed deep cities into the underground volcanic turf, a natural wonder in the Ihlara valley of Cappadocia (Kappadokia). Later the Greeks, and what was left of the Greek civilization in the VII’th century would protect and hide themselves from the Roman persecution of their Religion within the soft volcanic rock below the desert valley floor. How? How did they live? They lived well. They lived in peace and harmony among each other surrounded by protective volcanic rock (invisible to the eyes of invaders). The keys to their healthy life style were simple, light and ventilation. Derinkuyu is an ancient underground city with more than 13 different floors below ground and still gets excellent lighting and ventilation through vertical shafts at intersecting points throughout its complex and labyrinth structure to this day (even after millennia of wars and cave-ins).

Basement design can follow the ancient wisdom of these great civilizations. And windows are the key. A window without a shaft, also called a window well, is fine, if your time and budget will not allow anything else, but they make the difference between real and healthy underground living and just mere living. The effects of natural light on the human mind and body have been researched over and over, study after study… But who needs to be an expert to know that underground dwellings need to get at least as much natural light as the upper floors. Spacious windows are not just common sense; they are the best part of any decent basement design.
Ceiling basement design is one of the areas where people most get uneasy, but it can be simple, safe and sound, with little effort. Low hanging ceilings need to be covered with plates that come nearest to each and every surface and colored as brightly as possible. If the ceiling is not so low, then be sure and curve as much as possible around the edges, with arches that spring up from the wall.

The idea of springing up from the upper corner of a wall also should extend its design technique to the lighting as well. Make absolutely sure that light comes from about one foot or so from the top of the walls (all around the basement) and casts its ray up and out, blocking the light coming down, from the bulb. This will give the effect of space that the human eye needs to feel comfortable. Lights are traditionally put in the center of the ceiling, which is a big no-no… Whenever light bulb is stationed in the center of a room, shadows are cast on the ceiling… But it’s the ceiling that needs to be bright, the floor and walls are given priority by a center bulb, but by putting lights all around the top of the walls, not only the center and walls receive light, but also the walls and the floor as well. “Remember to throw light UP not down.”

Walls, floor, pillars, stairs, electricity and plumbing, all need to be designed in such a way as to permit more and more space. Colors should always be as bright as possible, and surfaces should be smooth with so light will bounce nicely off of them. Floors should be as warm as possible, and the walls should be filled with insulation. Interior decoration should conform to the rest of the house’s design, but inner workings like water heating, plumbing and electricity can be creatively hidden in walls and between pillars that close off spaces with false walls.

False walls and hidden closets spaces are not just for castles, in a basement design they create the illusion that this room is not a basement at all, while still making sure that it never looses its original purpose, easy internal maintenance. If a wall or a ceiling close off the access to anything that needs to be serviced later, then things can get really ugly in the new living room, and more expensive as time goes on. Expensive in the long run means the basement design was wrong and inefficient, so let the imagination go crazy with this.

Rerouting plumbing, electricity and moving the water heater, waterproofing the whole basement and digging window wells are not things you do to be fancy, they are put into the design to make remodeling the basement as cheap as possible. As strange as that may sound it is true… Basement design means being practical and practical is being prepared for the future. Make sure light comes from below and shoots UP. And finally, make sure that when planning your basement design, that you take into account as many false closets, walls, floors and even secret passages as possible to keep the uniform style with the rest of the house, without losing your basement.

Thursday, June 21, 2007

How basements start leaking

A rainstorm or melting snow temporarily raises the groundwater level. When water accumulates around the foundation, hydrostatic pressure builds up and causes the basement to leak. Clay-rich soils do not drain well and hold rainwater right against the foundation walls. Water pushes its way inside through cracks or joints and the pores in concrete.

As houses settle, concrete develops stress cracks that leak water. Exterior waterproofing cracks and disintegrates or separates due to the "alkali attack." Water also corrodes imbedded steel, which expands and cracks the concrete.

Water penetrates into the pores in concrete, dissolves alkalis, and enlarges the pores. As concrete ages, it becomes more and more porous. Initially, the seeping water evaporates, leaving on the surface lime that reacts with carbon dioxide in the air and forms limestone. Efflorescence is a telltale sign of capillary water seepage.

Slabs get even less protection than basement walls. The plastic "vapor barrier" soon disintegrates due to the lime in concrete and over time, the layer of gravel ("drainage pad") silts up. The concrete slab pulls in groundwater against gravity by capillary suction.

How can water get through concrete?

Concrete is naturally porous - typically 10 to 18 percent air (extremes 2-60%). To make concrete "workable," a water/cement ratio of 0.45-0.50 is used but cement only needs 0.25 w/c ratio for hydration. As concrete cures, the surplus water escapes to its surface where it evaporates. This "bleeding water" leaves a network of tiny capillaries (pores).

We cannot see the pores. Their size ranges from 3 nm (millionths of a mm) to 0.1 mm (the diameter of a human hair). The median is about 1 micron (1,000 nm) but a water molecule is 3,000 times smaller (0.28 nm). By all logic, concrete should leak like a sieve!

So, what holds the water back? Not the concrete but the physics of water itself. Although not as viscous as molasses, it takes pressure to push water through dry microscopic pores. Surface tension holds the "blob" of water inside the dry pore until its surface gets wet. But add a little water pressure during occasional rainstorms or condensation on the interior and after a while, the pores get wet and the concrete starts leaking. Concrete is hygroscopic - it attracts water by sorption and once wet, the pores draw in groundwater by wicking action (capillary suction).

But nothing holds back gases - invisible water vapor and radon gas flow right through the pores!

Types of Basement

A "walk-out" or "daylight" basement is a modern architectural form where the house is situated on a slope and part of the basement is above ground. Occupants can walk out at that point without having to use the stairs. For example, if the ground slopes downwards towards the back of the house, the basement is at or above grade (ground level) at the back of the house. It is a modern design because of the added complexity of uneven foundations; where the basement is above grade, the foundation is deeper at that point and must still be below the frost line.

In a "look-out" basement, the basement walls extend sufficiently above ground level that some of the basement windows are above ground level. Where the site slopes gently and is insufficient for a walk-out basement, a look-out basement will result. Sometimes, a look-out basement is deliberately constructed even on a flat site. The advantage is that the basement windows are all above grade. The disadvantage is that the main floor entry is above grade as well, necessitating steps to get up to the main floor. The raised bungalow design solves this by lowering the entry half-way between the main floor and basement to make a dramatic, high-ceiling foyer. It is a very economical design because the basement is shallower, and excavation costs are minimized.

A “walk-up” basement is any basement that has an exterior entrance via a stairwell. Some designs cover the stairwell with angled “basement doors” or "bulkhead doors" to keep rain water from accumulating in the stairwell.

When initially built, the main floor joists are often exposed and the walls and floors concrete (with insulation, where appropriate). Unfinished basements allow for easy access to the main floor for renovation to the main floor. Finishing the basement can add significant floor space to a house (doubling it in the case of a bungalow) and is a major renovation project.

Cellars

A cellar is a type of basement, primarily used for the storage of food and drink (especially wine) for use throughout the year. A cellar is intended to remain at a constant cool (not freezing) temperature all year round. Cellars are more common in older houses than in modern houses, and were important shelters from air raids during World War II.

Except for Britain, cellars are popular in most western countries. In Britain, people tend to store food and drink in a garage, if at all. However, the majority of continental Europeans have cellars. In North America, cellars usually are found in rural or older homes.

Crawlspace

A crawlspace (as the name suggests) is a type of basement in which one cannot stand up — the height may be as little as a foot, and the surface is often soil. While this cannot be used as living space, it can be used as storage, often for infrequently used items. These can be placed directly on the dirt, but it is more desirable to finish with either plastic or some sort of wood or concrete flooring. These are rarely included in houses as standard due to health and safety issues. However, they are frequently added on by home owners installing a small door into the foundations.

Basement Waterproofing and Crawl Space Moisture Control


If you have a wet basement or crawl space moisture problem of any kind, call us and we'll be there with experience and professionalism that will surpass your expectations. After all, drying a wet basement and wet crawl space is our business.

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