Moisture Testing

Ensuring that materials are dry is essential in healthy building. Building materials can be ruined by moisture damage. The follow­ing four building practices can cause warp­ing, deterioration of materials, and microbial growth:

1. Application of finish flooring materials over insufficiently cured concrete slabs

2. Failure to quickly and thoroughly dry out precipitation that enters an unfinished structure

3. Installation of wood members with a mois­ture content greater than 17 percent

4. Enclosure of walls containing wet-applied insulation systems, such as cellulose or spray foams, before they are properly cured

It is not always possible to detect by visual in­spection whether a material is wet. A variety of test procedures have been developed to as­sist in determining if a material is dry.

Drainage Layers

A rather common subsurface drainage system used to remove the infiltrated/seepage water from the pavement structures is by providing a permeable layer. Permeable layers should be at least 10-15 cm thick and extend under the full width of the roadway. They can be used under both concrete (PCC) and asphalt (AC) pave­ment surfaces. Permeable bases are usually located just above the subgrade and are discussed in more detail in the second part of Section 13.3.6. Permeable unbound granular bases must be separated from high plasticity subgrade soils by mean of geotextiles or impervious materials.

The drainage layer should drain into a longitudinal drainage pipe. In order to encourage the lateral flow of water, a minimum cross-fall should be considered, of, at least, 2%. For curved lengths of road and those with a permeable central reserve, the pavement bed must have a cross-fall of between 2% to 4% inclination, starting 1.0 m away from the paved area (marked with E in Fig. 13.6).

Fig. 13.6 Typical pavement cross-falls. E = position 1 m inwards from the edge of the pavement. Similar cross-falls will exist at road edges

Low-Energy Lighting: The Latest Bulb Technologies

Подпись: П MAXLITE © III

COMPACT FLUORESCENT LAMPS

An aversion to fluorescents is understand­able because they have been so awful for so long. They didn’t dim easily; they buzzed and gave off weird colors. And sadly, the push to offer CFLs at a price point close to that of a standard incandescent household bulb has given fluorescents a bad name all over again. The color of these cheap CFLs is poor, they burn out prematurely, and they aren’t dimmable. There are much bet­ter products on the market. Be prepared to pay more, but they will be worth it. Top – of-the-line screw-in CFLs by manufacturers like MaxLite™ and Earthtronics® (see "Bulb Sources," on p. 154) offer an energy – efficient, dimmable (down to 30%) light source that can be controlled by a standard incandescent dimmer.

A new category of CFL is the GU-24, characterized by a proprietary lamp and socket assembly that cannot be replaced with a standard screw-in incandescent lamp
(although MaxLite makes a screw-in adapter that allows a typical lamp to accept a GU – 24 socket). The GU-24 lamps meet Califor­nia’s Title 24, which requires that 50% of the wattage in kitchens must come from hardwired high-efficacy sources and 100% of the wattage in the bath must come from high-efficacy sources, unless controlled by a switched motion sensor.

For savvy people everywhere, lighting manufacturers are now offering decorative fixtures in modern and traditional styles that have hardwired fluorescent sources. CFL

Many use the new GU-24 socket and lamp technology, which is no bigger than a standard household bulb and socket assembly. They

Подпись:Low-Energy Lighting: The Latest Bulb Technologiescan be installed where there is an existing incandescent fixture and can be dimmed with the existing incandescent dimmer. No special wiring or dimmer is needed.

COLD CATHODE FLUORESCENT LAMPS

CCFLs are a newer generation of fluores­cent lamps. They can look just like regular household bulbs, globe lamps, or flame-tip lamps. They cost more than an incandes­cent, about $12 each, but save an average of $33 in energy costs over their lifetime. An 8w CCFL produces 40w worth of illumina­tion and lasts 25,000 hours, compared to an incandescent with an average rated lamp life of 750 hours. What makes them better than regular CFLS is their wide variety of color temperatures and that they can dim down a full 90% (CFLs can’t dim that much). Their swirls are thinner, and they’re more widely available than CFLs in low wattages. They are still a bit hard to find; they must be special – ordered through light­ing specialty stores or bought online.

LiGHT-EMiTTiNG DiODES

In use since the 1960s, LEDs were used as colored indicator lights. About three years ago, manufacturers came up with an LED source with the same color qualities of in­candescent light and daylight. These new LEDs use considerably less electricity than standard incandescent sources and last much longer—30,000 to 50,000 hours, while emitting no ultraviolet radiation. Even bet­ter, they contain no mercury, as do fluores-

Low-Energy Lighting: The Latest Bulb Technologies

cents. Companies like Cree Lighting® and Progress Lighting® offer both screw-in and hardwired LED kits as retrofits for existing housings, as well as IC-rated, airtight hous­ings for new construction.

SMA ON BRIDGE DECK STRUCTURES

Surfacing on bridge structures is not, and should not be, like that of a standard pavement on a soil subgrade. The essential difference lies in a different mode of operation. There are special circumstances that must be considered, including the following:

• The cooling and warming effect developing from underneath the bridge deck pavement caused by changes in air temperature under the steel struc­ture and faster changes of the pavement temperature due to wind action, which occurs faster and more intensely than in case of a pavement on grade

• Structural deflections of a bridge’s deck caused by passing vehicles

• The amplitude of bridge deck vibration, which is much higher than that of conventional road pavement

• Much more intensive applications of deicers, leading to the quick degrada­tion of asphalt mixes applied on bridges

For all these reasons, asphalt pavements on bridge decks are subjected to faster deterioration than their soil subgrade equivalents. Therefore, when designing a com­bination of bridge pavement courses, some additional points have to be observed as follows:

• The critical element influencing the pavement service life is the durable bonding of all the layers together (asphalt courses with a protection layer and the deck).

• The more flexible the structure, the more elastic the asphalt layers should be.

• Good compaction of the layers should be taken into consideration because it results in low-water permeability, although rolling on a low-stiffness bridge is challenging.

The deflections of orthotropic plate structures are usually higher than structures with cement concrete deck slabs. Consequently, when asphalt mixes are constructed on steel orthotropic structures, the most frequently applied asphalt mixes are those with the highest fatigue strengths (e. g., mastic asphalt with a highly modified binder) (Damm and Harders, 2000). In some countries, fine-graded SMA has been also used (see Section 13.2.1). Some interesting concepts and analyses can be found in several papers dealing with this subject (Huurman et al., 2003; Medani, 2001a; Medani, 2001b).

Company Goals

Job site goals need to be directed by overall company goals, which will vary depending on the owner’s desires. Here are some examples:

Sample Company Goals:

1. To provide income for framers and the company

2. To provide a safe and enjoyable work environment

3. To coordinate with the general contractor’s schedule and needs

4. To produce high-quality framed buildings

5. To grow the company

6. To develop framing skills

Communication

Communication is to a lead framer what a hammer is to a framer—one of your most important tools. Before you were a lead framer, you had to communicate with only one person—most likely the lead contractor or superintendent. As a lead framer, you will be communicating with these same people, but also possibly with the architect, engineer, owner, and the crew.

Each one of these people comes from a different environment, has different knowledge and experience, and different goals related to the job you are framing. Good communication is based on honesty, trustworthiness, openness, and effective listening skills. Keep in mind that bad communication creates problems, while good communication solves problems.

Communicating with Framers

Each framer who works for you will have his or her own unique characteristics, personality, background, and place of origin. It’s probably impossible to know all the sides of all framers, but the more you get to know them, the easier it will be to communicate with and teach them.

Communicating with the Framing Contractor, Superintendent,

Architect, Engineer, or Owner

We all know how to talk—some better than others. What we don’t always know is what to say and who to say it to. That will vary depending on the size of the job and the organizational structure of the companies doing the building. If you say the right thing to the wrong person, or the wrong thing to the right person, you might end up causing yourself delays and/or additional work.

The nature of the construction industry lends itself to communication errors. With each new building, you might be working with a completely new group. In many cases, an owner will select the team that will design and build the building. The architect may have a great sense of how the finished building will look and feel, but probably won’t be familiar with framing slang and concepts. The architect may hire an engineer to design the structural members of the building. Once the plans are complete, the owner will hire a builder who subcontracts the framing to your employer. You’ll then have to frame the building based on plans that may have been passed around, worked on, and changed by a group of people who may not have worked together before, and who may have varying degrees of experience or knowledge of what you have to do to frame the building.

Solving Problems on the Plans

Chances are, there will be some mistakes, omissions, and/or details on the plans that just don’t work. The parties involved in the design of the plans are capable of making mistakes in the same way you and your crew can make mistakes. Be ready to deal with these problems as they arise.

Good communication is probably your biggest strength when it comes to resolving mistakes or processing changes. The smaller the building, the easier it will be to navigate mistakes, and thereby reduce extra cost and time delays. Sometimes all it takes is a quick conversation with the superintendent. On bigger jobs, however, it may be necessary to get input from all members of the building management team, all the way back to the owner. In these cases, be sure to present the information in an organized way to prevent delays. The following five steps organize the process of solving problems with the plans:

1. Identify the problem: The information may be missing from the plans, or the design may just not work. It could also be that the information you need is in another part of the plans, not where it is usually located.

2. Have another framer review the situation: When you find a mistake, make sure it really is a mistake. One way to do this is to have one of your crew look at it. Even if he doesn’t have the knowledge to fully analyze the situation, just explaining it to him helps you review it in your own mind.

3. Develop a solution: It is usually worth your time and energy to develop an easy solution and write it down. Very often your suggestion will be accepted. This saves the person who made the mistake from having

to work out a solution—which could take days or even weeks and could be more difficult to frame than need be. Along with your proposed solution, you should note any extra costs that would result.

4. Identify and seek out the person responsible: Typically, if the mistake is in the architectural plans, it will be an architectural mistake. If it’s in the structural plans, it’s probably an engineering mistake. Quite often, however, it’s a coordination mistake between the architect and the engineer. If you’re lucky enough to

have direct availability to the parties involved, a quick phone call might provide an easy solution. Remember that framing contractors, general contractors, architects, engineers, and owners all have relationships. Go to the source whenever possible, but be careful to go through proper channels for communication. Get permission, if necessary, to directly contact the appropriate party.

5. Clarify the solution: Each job has its own chain of authority. Sometimes the general contractor takes responsibility for solving problems; sometimes it’s the owner or architect. Direct your suggested solution to whoever accepts the authority. Whether they agree with your solution or propose their own, be sure it is written down and dated, along with the name of the person who proposed the solution. Write it on the plans for easy reference. Do this while the person is still there to make sure you understand their interpretation of the solution. This way, you’ll be protecting yourself in case of any future confusion.

Delayed Communications

Organizing your communication is another important task of a lead framer. For example, you might realize that you need more material or hardware, but the person who orders it is not on the site. By the time you see that person, however, you are onto another task and may forget to let them know what you need.

The easiest way to avoid this problem is to carry a small notebook in your pocket, and write down what you need, whether it’s information or materials. Get used to checking your notebook whenever you talk to the people who supply your material or process your change orders, or when you are making phone calls. The notebook acts as a memory aid when communications are delayed.

Assigning Framers Tasks

As lead framer, your most important job is to assign framers to tasks. If they are unfamiliar with the
tasks, it’s part of your job to teach them how to do the work. It may be tempting to just grab the right tool and take care of the problem yourself, but if you don’t teach your crew, they won’t be able to work independently, and neither will you.

Organizing your crew and assigning tasks can be the easiest part of your job, or it can be the most difficult. A lot of it has to do with the framers you have working for you, and the way you manage them. For example, one individual with a bad attitude can disrupt a whole crew, or a crew without proper direction can work all day and get little done.

When you first start leading, you’ll quickly realize that it takes a lot of preparation to keep the whole crew busy all the time. As each framer finishes a task, you must have another task ready. If a task isn’t ready, the framer(s) will have to wait around while you get it ready for them.

If you are working on a task and one of your crew needs something to do (and you don’t have anything else for him to do), show him what you are doing so that he can help you or take over. Or have him get started on the next phase of the job. The point here is that if anyone is going to be standing around scratching his head, it should be you, because you can always use the time to plan for the next step.

Analysis of Crew Performance

For your framers to become better framers, they should have an understanding of how well (or not) they are performing their jobs. Crew analysis is the process of answering this question. It is important to know the capabilities of each framer, so you can assign him to the kind of task where he’ll be most productive and know how much supervision or instruction he needs. Discuss these things with your framers. Their feedback will help you understand and evaluate them.

The “Framer Analysis" form can be used to evaluate your crew and to show your framers what aspects of their work are important to you. This is also a good format for deciding wage increases based on performance. The framer who consistently gets high ratings may get more money if he reaches a certain skill level.

To use the form, give the framer a rating from 1 to 10 for all the items listed. The “Value Factor" column in this form is an estimate of the comparative value of the productivity items. You can change these values to your own preferences. Enter your rating in the column titled “Framing Rating 1 to 10." Multiply the rating by the various value factors and put the results in the column labeled “Total." Add the total ratings. This will give you a value you can use to compare your framers’ performance. You can use the Framer Analysis form for your own planning purposes or to show framers where they need to make improvements.

STEP 8 PAINT THE EXTERIOR SIDING AND TRIM

On our Charlotte house, we didn’t have a lot of exterior painting to do. We installed vinyl siding, soffits, and windows and covered fascia and rake boards with aluminum cladding. But we still needed to do a bit of exterior paint­ing (door casings and doors, for example). On houses with more exposed wood, you should know how to paint the exterior correctly. Here are some guidelines you can use to make sure your exterior finishing work will look good and hold up well.

Choose an exterior finish

Wood siding, such as shingles or clapboard, is often better off when finished with stain rather than with paint. Solid-color exterior stain gives wood a paintlike appearance, but it does not crack or peel the way paint can. To let more of the wood grain show through, use semitrans­parent stain, which is available in many wood tones and colors.

STEP 8 PAINT THE EXTERIOR SIDING AND TRIM

You can never have too many volunteers when it’s time to paint.

We use brushes and rollers of all different sizes.

Painting a new house is great because you don’t need to worry about getting paint on carpets and furniture.

People with rollers paint the walls and ceilings quickly, but it’s just as satisfying to work on trim with a brush.

Whether you choose paint or stain, make sure you buy a good-quality finish that is recommend­ed for the use you have in mind. For example, you don’t want to paint a deck with porch enamel or use interior trim paint on exterior wood. The pressure-treated lumber used on many decks needs a penetrating sealer or stain rather than paint. Upright pressure-treated porch posts can be painted or stained with a solid color once the wood is clean and dry. Find out which brands and formulations knowledgeable painters and paint suppliers in your area recommend.

Gardermoen Airport in Oslo

During the 1990s, a few airfield pavements paved with SMA mixtures were constructed in Norway. Various binders and additives were used, depending on the climatic zones in which they were placed. The biggest of these airfields with an SMA pavement is Gardermoen near Oslo. On Gardermoen’s runways, 4-cm thick SMA mix of 0/11 mm were placed on the western runway) and 4-cm thick SMA mix 0/16 mm was placed on the eastern runway. Two SMA runways, 3300 m and 2950 m long, were constructed there with styrene-butadiene-styrene (SBS) modified binders (Larsen, 2002).

13.1.3 Johannesburg Airport

In 1999 the following comparative trial sections of different mixes applied in new asphalt wearing courses were laid down at the international airport in Johannesburg, South Africa (Joubert et al., 2004):

• 0/19 mm asphalt concrete (continuous graded coarse mix)

• 0/9 mm SMA with tested parameters: binder content 7.1% (40/50 Pen type), voids in mix 5.7%, stability 6.7 kN, flow 4.0 mm, passing by sieve 2.36 mm 17%, density in place 92%

• 0/13 mm porous asphalt concrete

These mixes were also compared with the existing old wearing course of continu­ously graded mix.

All sections were located in the landing area, a zone of heavy dynamic loads. Tests were aimed at determining the practicality of various mixes, assuming ungrooved pavements. The surface integrity of the section of pavement and its surface proper­ties were inspected periodically. Special attention was paid to antiskid properties, lifespan, and the buildup of rubber with time (worn-off the airplane tires). The results for the SMA section were as follows:

• Grip number—initially 0.64, after 5 months 0.71

• Surface texture—initially 1.33 mm, after 5 months 0.9 mm

The summary of SMA’s performance on the trial section pavement proved that the surface properties of the tested SMA layer were better than the other mixes tested in the trial sections. The porous mix was also recognized for its good characteristics, with the exception of its durability, which was the lowest of those tested here. The conventional asphalt concrete pavement demonstrated poor antiskid properties and therefore needed grooving (Joubert et al., 2004).

TIPS FOR THE PAINT STORE

Before heading for the paint store, calculate the square footage of surfaces to be painted. Then compare those figures with the coverage figures listed on the paint containers. Unless a wall is preponderantly glass, don’t bother to subtract the square footage of windows and glass doors from your total. You’ll eventually need the extra paint for touchups.

TIPS FOR THE PAINT STORE

Although some artists can hand – tint 5-gal. quantities to match existing paint, the rest of us should rely on paint-store mixologists. They have color charts, recipes, and accurate measuring tools.

The blue object at the lower right is a power-drill paint mixer.

 

image895

to Thin о

_____ •____ A. jlL*_____ »____ i_L

Подпись: OR NOT TO THIN?Подпись:Подпись: PROnP Less expensive than finish paints, tinted primers also hide more and therefore ensure a more uniform finish color. So you can save money by having your paint store tint the primer closer to the color of the finish coat. This is especially true if you're painting over existing paint that's darker than the new paint. 1111 Подпись: Predicting the coverage of stains is more difficult, especially if the wood is untreated. Add 15 percent to 25 percent if you need to special- order the stain and must wait more than a day or two for delivery. That way, you'll be ensured of enough stain to finish the job. If your paint job will be large, save money by buying 5-gal. rather than 1-gal. quantities. However, if it's more cost-effective to buy only a few 1-gal. cans, ensure uniform color by mixing their contents in a clean, empty 5-gal. bucket. This way, you'll avoid finishing one can in the middle of a wall and resuming with a noticeably different hue. Подпись: You may be able to extend the life of a filter cartridge by removing it from the mask, placing it in a sealed plastic bag, and putting it in the refrigerator. If you leave cartridges in a mask merely hanging in your shop or garage, they will be dead in about 3 weeks.Подпись: bntortnf tht cityПодпись:Подпись: Protect your lungs whenever you sand, scrape, or strip paint-even if there's plenty of fresh air. While heating old paint for scraping, this worker is wearing a lightweight dust mask with P100 particulate filters.image896Speaking of mixing, have your paint store mechanically shake the paint for you—unless, of course, the manufacturer’s instructions indicate it shouldn’t be shaken. For example, polyurethanes and varnishes trap air bubbles when shaken.

Superimposed versus Terraced Structures

There are instances when one MSE wall is built on top of another. In certain instances, these walls can be considered to be two independent structures, each requiring its own internal design and external stability. The global stability of the slope must be suffi­ciently stable so as not to undermine the stability of the entire embankment.

Figure 8.36 shows a superimposed structure. The walls are such that the load of the upper wall level serves as a surcharge load on the lower wall. Each wall is independently designed.

FIGURE 8.35 Foundation pressure for MSE wall calculated by the AASHTO method based on Meyerhof. (From the Reinforced Earth Co., with permission)

FIGURE 8.36 Superimposed MSE walls. (From the Reinforced Earth Co., with permission)

This design approach does not hold when the MSE structures are directly superimposed, one on another, as shown in Fig. 8.37. Such terraced arrangements are sometimes used for high walls. These offset structures are obviously similar to a single embankment with a sloping face. They exhibit essentially the same overall behavior, and are designed as sloping faced walls.

FIGURE 8.37 Terraced MSE wall. (From the Reinforced Earth Co., with permission)

Culture Collection

Special moist, sterile swabs called culturettes are good for this type of sampling. The cul – turette is presterilized and comes with a fluid- filled glass ampoule to provide just the right amount of moisture. The ampoule and swab are housed in a sterile plastic tube. About one minute before collecting the sample, squeeze the area of the tube over the ampoule to break the ampoule and release the fluid, which then soaks the cotton swab. Slide the moistened swab from its sterile tube and use it to wipe one square inch of the area to be tested. Then in­sert the swab back into the sterile plastic tube for shipment to the lab. Since this method uses liquid, the fungal spores will be hydrated and begin to colonize. It is important to ship the specimen to the lab via overnight delivery ser­vice or the test may be invalid.

Vacuum Dust Collection A filter designed to fit on a domestic vacuum cleaner is used. Since the filter’s pores are smaller than mold spores, any mold spores present are collected. The filter canister is then shipped to a laboratory for analysis.

Other Mold Test Methods The practice of testing for molds by letting spores settle on an open culture dish is now discouraged by knowledgeable specialists. Since certain harmful molds such as Aspergil­lus and Penicillium are very light and have a tendency not to settle on culture dishes, they are underrepresented in the analysis. Other methods of testing for airborne fungal spores and contaminated materials are available but require a trained technician with sophisti­cated equipment.

Radioactivity Testing

Although radioactivity in building materials is rare, John Bantas home inspections have revealed radioactive stone and tile glazes. Highly radioactive materials can be tested simply by holding a radiation detector next to the material.

For lower levels ofradiation, measurements of longer duration should be performed. Place at least one pound of the material in ques­tion in a glass container with an instrument for measuring radioactivity. A useful instru­ment designed for this purpose is Radalert loo, whose small size allows it to fit easily in­side a one-gallon glass pickle jar along with the material to be tested. Set the meter for to­tal counts and leave it to measure for a timed period of 12 to 24 hours. As a control, the test must also be performed in the same way, in the same location, but with the jar empty. Re­peat both tests several times to be sure a radia­tion-emitting solar flare or short-term cosmic event did not interfere with the results. To ob­tain an average count per minute, divide the total number of counts recorded for each test by the total number of minutes the test ran. A substance that measures less than 10 percent higher than the control test is considered to be free of radiation. Readings more than 20 per­cent higher than the control test are consid­ered to be significant.