Drainage Systems

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Drainage systems come in many shapes and forms (see Chapter 13) but they also share many common features – they are placed lower than the section of road or earthworks they are intended to drain and they comprise materials (and/or pipes) that

Подпись: Fig. 1.11 A gravel-lined swale with planted reeds to function as a soakaway. Reproduced by permission of VicUrban Note: Infiltration is encouraged by providing a porous surfacing.
Drainage Systems

are more permeable than the surrounding materials. Broadly, they may be classified as follows:

i) Horizontal (or sub-horizontal) drainage layers.

– When placed in, or more usually at the bottom of, some imported soil used for earthworks, these are termed blanket drains. Then they are used to isolate earthworks from underlying groundwaters, allowing any up-flowing water to be intercepted before it causes deterioration of earthworks and to catch water draining down from higher layers.

– Drainage layers may be provided only to carry small seepage flows con­sequent upon leakages in the otherwise impermeable pavement surface. Typically these are provided as an integral function of one of the road’s construction layers.

ii) Vertical, in soil, drainage trenches.

– Some are intended to provide drainage of earthworks structures. The amount of water to be carried (and, hence, the drain’s design) will depend on the
permeability of the ground to be drained and on the height of the natural water table.

– Pavement median or edge drains are usually installed at the edge of pave­ments, often extending down into the underlying natural soil or into the earthworks. Depending on the arrangements in force these may be expected to handle runoff water arriving from a pavement surface as well as from seepages carried to the pavement edge by a drainage layer (ib. above).

iii) Drains for structures. Drainage systems are usually installed behind constructed walls and bridge abutments so as to reduce the lateral water pressures on these structures. They are not considered in this book.

Conventional drains are provided by aggregate, with a low proportion of fine sizes, placed in or under the zone to be drained. When the natural ground, imported earth­works, or pavement layer that is to be drained is particularly fine graded, it may be necessary to place a filter layer between the natural soil and the drainage system element.

Nowadays, alternatives to aggregates are available to effect drainage. Except where large flows are expected, geosynthetic fin drains comprising an exterior “filter fabric” and an interior highly permeable core are generally accepted as suitable sub­stitutes for drainage ditches. They can be installed very rapidly and avoid expensive quarrying and associated transport of large volumes of dense materials. The “filter fabric” layer of the composite geosynthetic will normally be a felt-like layer around 1mm thick having a fairly small pore size. Although its pores will be too large to prevent every grain of the surrounding soil from going through into the interior core, they will halt somewhat larger particles that will, in their own turn, then allow layers of progressively finer particles to block the gaps between them. In this way a natural bridging layer will develop such that an effective filter zone will be catalysed by the “filter fabric”.

Where low flows are expected, the water may be carried within the drainage medium (stone or geosynthetic), but where moderate or high flows can be antici­pated it becomes necessary to install a pipe at the bottom of the trench or fin. This has to be permeable in some way (slotted, holed or integral with the fin drain) so that the water collected by the drain may be fed to the pipe and thereby carried away.

Tools

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The tools in this chapter are a subjective col­lection. Yours should be too. Choose tools that are right for the scope of your renovation, your experience, your storage space, your budget, and your physical strength. Because tools become an extension of your hands, shop for tools that are comfortable to use. Other specialized tools are presented in pertinent chapters.

Tool Safety

Few things will slow a job more than an injury, to say nothing of the pain and expense involved. Don’t be afraid of tools, but respect their power and heed their dangers. The following sugges­tions come from professional builders and tool manufacturer owner’s manuals, so read and heed them. Always comply with safety tips provided in tool-operating manuals. Some may pertain to features or hazards unique to particular makes and models.

ESSENTIAL SAFETY RULES

Keep the work area clean. This is especially important during demolition.

► Clean up as you go. You’ll accomplish more if you can move freely.

► Pull nails from removed boards at once. If you’re lugging lumber across a work site or descending a ladder in a hurry, you don’t want to step on a nail that’s sticking up.

► Clean up when you complete each work session. This seldom takes long and usually means fewer misplaced tools. Plus it lets you get right to work the following morning.

Wear safety gear. See the section "Safety Equipment” for details on hearing protection, safety glasses, a hard hat, work gloves, and so forth. Avoid wearing baggy clothes or dangling jewelry; these are especially dangerous when you’re using power tools.

Подпись: Safety equipment. From left to right, top: hard hat, work gloves, and knee pads; center: ear plugs, safety glasses, safety sunglasses, and hearing protection; bottom: head lamp and respirator mask. Disconnect electricity. (^) Be sure to cut off the

electricity to the areas you’ll disturb. Then use a voltage tester to double-check that current is off in affected outlets. Also avoid cutting or punctur­ing wires hidden behind wall surfaces.

Plan the job and pace yourself. The job will go

more safely and smoothly if you assemble your tools and materials beforehand. Take regular breaks, and you’ll stay sharp longer.

Don’t work when sick. Take the day off when you’re excessively tired, preoccupied, or taking any substance that impairs your judgment.

Operate tools safely. Study, and comply with, tool manufacturer owner’s manuals. Never remove safety devices. Avoid electrical tools whose wires are frayed, cut, or exposed. Never force tools—saws can kick back and high-torque drills can knock you off a ladder.

Don’t work alone. When you’re on a steep roof or a tall ladder, make sure someone is close by.

He or she needn’t be working with you, but should be within earshot if you need help. If you need to work alone, have a cell phone handy.

Keep work areas well lit. Don’t work where the light’s poor. If you disconnect the power to a work area, run an extension cord and droplight to it.

Miscellany. Keep kids away from work sites. If you store equipment at home, lock up power tools, dangerous solvents, and the like.

In Egypt, the Nile flood is a blessing

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Agriculture developed in Egypt about 5000 BC, perhaps under the influence of Mesopotamia and Syria. Subsequently, the need to take maximum advantage of the flood for land fertilization and irrigation led naturally to the organization of human resources for this purpose. Flood risk on the Nile is less than on the Euphrates and Yellow Rivers. The Nile has a relatively regular annual flood cycle, but still has suffi­cient variability, from one year to the next, to cause plenty or famine. The importance of the use of the flood in Egypt appears in numerous texts. In the Book of the Dead, in the heart of a long litany in which a person, embarking on a final voyage, proclaims his (or her) purity, are the following verses:

“I have not stopped water when it should flow. I have not made a cutting in a canal of run­ning water.”[19] [20] [21]

or again, from the Book of the Dead:

“O Osiris I am your son Horus and I come to work your fields for you.

“O Osiris I am your son Horus and I come to irrigate your land”

“O Osiris I am your son Horus and I come to work the land according to your intention”

20

“O Osiris I am your son Horus and I come to dig canals for you”

One can see in this hymn to the Nile, dating from about 1365 BC, a rather moving parallel between the blessings of the flood in Egypt and the benefits of the rain in other lands:

“Thou createst the Nile in the nether world below, and thou bringest it at thy will to provide life to the men of Egypt, the men thou created for thyself. […] Thou also giveth life to the most dis­tant foreign lands, for thou givest them the Nile descending from the heavens (i. e. rain). […] The Nile in the heavens is for the foreigners, and for all animals of foreign lands who walk on their feet. The Nile that comes from the world below belongs to the beloved Land.”^1

A LITTLE GEOMETRY

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A little geometry is needed in the plumbing trade. Whether you are work­ing with roof drains, figuring floor drains, or doing almost any part of plumbing paperwork, you may be using geometry. I hated geometry in school, but i’ve learned how to use it in my trade and how to make the use of it much more simple than I ever used to know it to be. I’ll share some of my secrets on the subject.

Plumbers use geometry to find the distance around objects, to find the area of objects, to determine volume capacities, and so forth. A lot of plumbers probably don’t think about what they are doing as geometry, but it is. So, let me show you some fast ways to solve your on-the-job problems by using geometry that you may not even realize is geometry. Think of what we are about to do as just good old plumbing stuff that has to be done.

Rectangles

Rectangles are squares, right? Wrong, they are rectangles. Squares are squares. Got ya! Now that I have your attention, let’s talk about the methods used to de­termine perimeter measurements for a rectangle. A flat roof on a commercial building is a good example of a rectangle that a plumber might need to work with for rainwater drainage. This exercise is too simple. To find the perimeter (P), you multiply the length (L) by 2 and add it to the width (W) that has also been multiplied by two. The formula looks like this: P = 2L X 2W. Now let’s put this into real numbers. Assume that you have a roof that is 80 feet long and 40 feet wide. What is the perimeter of the roof? First, do the math for the length. Taking 80 X 2 will give you 160. Do the width next. You will find that 40 X 2 is 80. When you add the 80 to the 160, you get 240, which is the perimeter of the roof. Not too tough, huh? Didn’t I tell you that I’d make this stuff easy?

A Square

A square has a perimeter measurement. Do you know how to find it? This one really is too simple. Add up the measurements of the four equal sides and you have the perimeter. in other words, if you are dealing with a flat roof that is square with dimensions of 50 feet on each side, the perimeter is 200 feet. This is established by multiplying 50 X 4. They don’t get any easier than this one.

The Yellow River valley and its catastrophic floods

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In China, agriculture first appears about 6000 BC along the Yellow River. Omnipresent in the beginnings of the Chinese civilization is the legend of its founding hero, Yu the Great. In about 2000 BC Yu was apparently “master of River Control.”

“In ancient times Emperor Уй deepened the rivers and saved the empire from flood, bringing relief and security to the nine provinces.”[17]

During this time, according to legend, “the flood waters rose as high as the sky”.[18]

Yu’s father, Kouen, had earlier been given the responsibility to curb the floodwaters, and constructed dikes over a nine-year period. But he failed in his assignment and thus was banished. Yu then decided to sacrifice himself to the river, taking the sins of all upon himself. The river, it was said, took half of Yu (tradition has it that half his face was shriveled and that he dragged one leg). He took a different approach from his dike­building father. During a period of 13 years, during which he never once returned to his home (according to legend), Yu dug canals and channels and dredged the rapids.

“He led the Rivers to the sea, as lords file to the court”.

Tradition credits Yu with a superhuman exploit: digging the channel of the Door of the Dragon (Longmen pass, see Figure 8.2) to provide an outlet for the waters of the Yellow River. Yu succeeded where Kouen had failed, and became the founder of the legendary first dynasty of Xia.

In ancient China, animals and even humans were sacrificed to the Yellow River before the followers of Confucius put an end to this practice. The battle to control the rivers, and to provide protection from their floods, is a constant theme in the hydraulic history of China. We return to this theme in Chapter 8.

Home Remedies for Energy Nosebleeds

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■ BY BRUCE HARLEY

M

y friend Terry Brennan told me that on his first job as a mason’s tender he learned two things: "Whatever I did was wrong," and "If the work wasn’t going to show, don’t strike the joints" because it didn’t have to be pretty. Now, not taking the time to smooth out a mortar joint that no one will see may not rank as a great offense. But the fact is, many things that go wrong in home building go wrong where sloppy work is done because "it’s not going to show, so it doesn’t matter." I know this because as an energy consultant, I plug the same nose­bleeds in new and old homes alike. We’re good at cutting construction costs but bad at building houses that serve their owners well, minimize operating costs, and also reduce pollution.

Gaps in the Construction Sequence Cause Many Problems

People think windows and doors are the big­gest leaks in a house because windows and doors are the most visible holes. But even old windows and doors are relatively small holes. In reality, the majority of energy leaks happen in places you can’t see, where one subcontractor’s work ends and another’s begins: behind the drywall, up in the attic, or down in the crawlspace. Even when each trade does its job well, problems can occur because nobody sees the big picture. The way the work fits together is as significant as the work itself.

The gaps between subs’ responsibilities usually translate into gaps in a house’s ther­mal boundary. These gaps are addressed in current building codes, but building inspec­

tors can’t always offer protection. Sometimes they don’t understand; sometimes they just don’t enforce energy codes. The architect, the general contractor, or the homeowner must take the responsibility for understand­ing and closing these gaps.

Home Remedies for Energy NosebleedsAmazingly, the two trades most concerned with energy efficiency—HVAC (heating, ven­tilation, air-conditioning) and insulation— rarely follow the minimum industry standards for their work. The reasons differ, but they share one common element: Their work is hidden behind drywall. The only feedback they get is when these systems fail, when our homes are uncomfortable (an issue that’s often misdiagnosed) and high energy bills mount. Pressure to keep up­front costs low and underestimating the magnitude of these problems are also com­mon to both trades. This standard of care isn’t reasonable. Just because it has always been done this way doesn’t make it right.

RYNERSON HOUSE

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The renovators: Juanita and Steve Rynerson had lived in the original house 14 years while raising two sons. According to Juanita, a teacher, and Steve, an architect, "we no sooner had an empty nest than we demolished it.” To make an ambitious renovation affordable, they house-sat various houses for a year, which required that they move from house to house, while working full-time jobs and overseeing the renovation.

The house: This two-bedroom Craftsman cot­tage was built in 1915. In the mid-1960s, accord­ing to Steve, "the previous owners stuck their heads in the attic and said, ‘Oh, we can put two more bedrooms up here.’ ”

What worked: Great schools, nice neighborhood, large pleasant backyard. Being an old-house per­son, Steve loved the architectural elements that had evolved over a long time and gave the house integrity—the formal dining and living rooms toward the front of the house, the wide trim and high ceilings, the graceful overhangs.

What didn’t work: From the start, Juanita found the house dark and depressing. Both agreed that, given the scant light, poor traffic
flow on the first floor, and serious structural problems on the second, only major remodeling would set things right. Together, they created a detailed list of the cottage’s shortcomings (see the drawings on p. 26).

► The layout along the back of the house was "a mess," with four rooms—a small bedroom, a laundry, a kitchen, and a bath­room with a shower and tub—crammed into the building’s 30-ft. width. The kitchen was little more than a closet with a water heater.

► The house was uninsulated, with a single floor-furnace for heat.

► The second floor was not worth saving.

The rafters were skimpy 2x4s, spaced a too-wide 32 in. on center, with 3 ft. 6 in. overhangs—"more like a tent than a roof," Steve noted. The original attic floor joists were 2x4s, and when the previous owners converted the attic into bedrooms, the increased loads sagged the ceiling (and floor) of the dining room below.

Constraints: To avoid the hassle and delay of seeking a zoning variance (or knocking down the house and starting over) the Rynersons decided not to increase the existing house footprint. Also, they didn’t want to encroach on the backyard.

image82
Подпись: VlBRpJfr A view from the living room, looking southeast, shows how extensive the renovation was. At right are the original front door and entry trim.

After renovation: Although the remodeling raised the ridge 6V2 ft. and added 750 sq. ft. of living space, from the street, the house looks smaller than it is.

Before renovation:This two-bedroom Craftsman cottage was built in 1915.

Подпись: Creating a light-filled living room required some work—namely, demolishing a dark porch, moving the wall out, raising the ceiling, and expanding the bank of windows.image83Подпись: ■image84Подпись:

And they wanted the new design to respect the scale of the houses around it.

The plan: Build up. Add a second story, but maintain the intimate cottage feeling. (One of their interior designers referred to the new design as "a Craftsman on steroids.”) Improve first-floor traffic flow, move the master bedroom upstairs so it will have more natural light and long views, upgrade and add bathrooms, and tie the house to the backyard.

Compromises: Steve noted, "Renovation is kind of a slippery slope, so we ended up replacing more of the house than we anticipated. A lot of it was structural stuff we had to do. So the project took longer and cost more. You deal with it.”

Surprises: House-sitting was an adventure. A year of living simply—living on houses rather than in them—forever changed the way the Rynersons live. Their renovated house is spare and uncluttered. Combining the roles of architect/ client and husband/wife was also a challenge, but the constant communication required by the remodel brought them closer and reminded them, over and over, of the traits they cherished in each other.

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Once you enter the front door, the space opens dramatically as the stairwell soars two stories. As Craftsman-inspired as the renovation is, this entry leaves historicity behind. The squiggly railing, the floating ceiling fixtures, and the wall colors are light-hearted and new.

All in all: The workmanship is exquisite, relying more on the subtle beauty of natural materials than on fancy edges or shiny finishes. Simple shapes; honest forms. In one bathroom, as shown on p. 323, we see fine-grained black granite coun­ters, luminous cherry cabinets, and nautilus­shaped fossils swimming in limestone that was a seabed in Jurassic times.

Shared thoughts: Juanita mused: "The painter ran late, and the house reeked of fresh paint the day we were to move back in. Sometimes, you just have to let things go. So we pitched a tent under the redwood in the backyard, ran an exten­sion cord to the house so we could watch TV, and camped out for a few days. It was good to be home.”

The new floor plan improved traffic circulation dramatically. Beyond the dining room, a gourmet kitchen opens to a lush backyard.

Chronic Illness from Acute Exposure to Virulent Mold Species

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In 1993 when Tomasita Gallegos was 37 years old she first consulted Dr. Elliott. At that time she was frightened, in a state of severe agitation, and somewhat disoriented. Her face was bright red; her mouth showed increased salivation; her eyes were watery with constricted pupils; and her skin was warm to the touch. She was referred to Dr. Elliott by another physician, who felt she might have experienced a pesticide exposure.

Ms. Gallegos was employed as a housekeeper in a private home. The morning of the day she became ill, she was instructed to clean the guest house, which had been recently occupied. Shortly after the patient entered the guest house, she be­came acutely ill with the above-mentioned symp­toms. After the acute symptoms subsided, she was left with multiple problems, including chronic fatigue, panic attacks, chest pains, headaches, memory loss, and extreme chemical sensitivity. Her constellation of symptoms was baffling since it was determined that no harmful chemicals had been used on the premises.

An environmental engineering company was consulted to evaluate the guest house. Upon removing the furnace and cooling coils to allow access for a thorough cleaning of the ductwork system, the consultant found approximately two inches of water with green slime at the bottom of the supply plenum. Because the area was dark and cool and in the direct airstream of the house ductwork, the spread of microorganisms was very likely. Close inspection revealed that a defec­tive humidification system was the source of the leaking water. Most of the microbial agents were fungi that, although found widely in nature, were highly concentrated in the interior environment. Many fungi produce toxic compounds called mycotoxins. The intense microbial exposure had the effect of sensitizing the patient, leaving her with an overreactive immune system, commonly known as environmental illness. At present, with diligent avoidance of molds, toxic chemicals, and allergens, Ms. Gallegos is slowly beginning to re­gain her health.

Discussion

Whywasthispatientso severely affected from such a brief exposure? The type of mold was a particu­larly virulent species. In addition, some individuals are more susceptible to fungal contaminants than others. If the detoxification pathway in the liver is already at maximum capacity, it might take only a relatively small exposure to overwhelm the sys­tem. This theory is called the rain barrel effect and refers to total toxic load. When more toxins enter the "barrel" than the body can excrete, the barrel overflows and symptoms develop.

to be found only in older homes, mold can be found wherever moisture accumulates, such as basements, bathrooms, windowsills, laun­dry rooms, or wherever leaks and flooding oc­cur. Moist building materials, including new materials, can become breeding grounds for mold and bacteria within a few days. Many of the materials used in standard construc­tion of new homes are susceptible to water damage and fungal growth. A moldy home is frequently a sign of a home with deteriorat­ing building materials. Even when molds are

Development

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For years the U. S. Department of Housing and Urban Development (HUD), the National Association of Home Builders (NAHB), and the NAHB National Research Center (formerly the NAHB Research Foundation, Inc.) have been searching for solutions to the rising cost of housing.

The Joint Venture for Affordable Housing (JVAH) program has been. a significant step toward lowering _ housing costs. This manual contains a compilation of proven cost-reduc­tion methods of land planning and development, as well as actions local governments can take to _ encourage more affordable housing.

All the techniques may not be applicable in every situation, but most builders will find many ways to lower housing costs. Volume II, the companion manual, contains proven cost-saving construction techniques.

Acknowledgements

This manual is the result of material obtained from the Joint Venture for Affordable Housing Demonstration

builders and from other sources. It was prepared for the Department of Housing and Urban Development by the NAHB National Research Center. The demonstration program was directed by the Office of Policy Development and Research.

The principal author was Carol Baker Schaake, with assistance from E. Lee Fisher, Mark S. Nowak, Ralph Lee Smith and others who provided years of residential research effort and documentation. Most importantly, we wish to thank the builders of the JVAH demonstrations and the com­munities who took the risks and put their resources on the line to prove that affordable housing for all Americans can be a reality.

The work that provided the basis of this publication was supported by funding under a contract with the U. S. Department of Housing and Urban Development. The substance and findings of that work are dedicated to the public. The authors are solely responsible for the accuracy of the statements and interpretations contained in this publication. Such interpretations do not necessarily reflect the views of the Government.

Preservative Treated Wood

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Preservative Treated Wood

The treating of wood in recent years has gone through some major changes. The most important thing to know is that there are different types of preservative treatment and that some of the treatments require specially coated fasteners to prevent corrosion.

A little history will help in understanding. For years the predominate chemical for preserving dimension lumber had been chromated copper arsenate (CCA). However, health concerns arose because of the arsenic content in CCA, and in 2004 the Environmental Protection Agency (EPA) required labels on CCA, which had the effect of disallowing the use of CCA-treated wood for most residential uses.

The first commonly used substitutes were copper azole (CA) and alkaline copper quaternary (ACQ). These eliminated the arsenic but created a different problem because they were corrosive to steel fasteners. To solve this problem, hardware manufacturers began making their common fasteners with a galvanized coating. For example, if you see a Simpson Strong-Tie hardware labeled Z-max you know it has been coated so that it can be used with CA and ACQ. Steel nails also had to be coated when used with lumber treated with CA or ACQ. Typically they are galvanized. Stainless steel is a better substitute for hardware and nails because it is less corrosive, but it is expensive.

Sodium Borate (SBX) preservative treatment is another substitute for CCA that does not have the problem of causing corrosion of steel fasteners, however it will wash out of the lumber with liquid exposure. It is specified for use above ground and continuously protected from liquid water.

New products are continually being developed. Carbon based compounds are among these and could prove to be less corrosive and natural in color.

The 2009 IBC & IRC code states that preservative treated wood should be in accordance with AWPA U1 (American Wood Protection Association Use Category System) for the species, product, preservative, and end use. The lumber tag attached to the treated wood will give the use category to assist you in making sure you are using the correctly treated wood.

All the different labels and chemicals can be confusing. Most importantly, make sure that you are using the right treatment for the task at hand and that you are using corrosive resistant fasteners where necessary. To check the correct use of treated lumber, read the tag attached to the lumber or ask the lumber supplier. For CA or ACQ treatment, you will need corrosion-resistant fasteners; for SBX or other borate treatments, you will not need corrosion-resistant fasteners. Beyond that, check on the fastener boxes for specifications or ask the lumber or fastener supplier.

Preservative Treated Wood