Blog Archives

CHIMNEY FLASHING

Posted by on 13/ 11/ 15

Chimneys must be counterflashed(see p. 74). The upper pieces of counterflashing are usually tucked into chimney mortar joints and made to overhang various pieces of base flashing, which are nailed to the roof deck. Counterflashing and base pieces overlap but aren’t physically joined, so they can move independently yet still repel water. (This independence is necessary because houses and chimneys settle at different rates, causing single-piece flashing to tear and leak.)

Closed Valleys

Подпись: CLOSED-CUT VALLEY image147Подпись:Подпись: Cut shingles stop 1 in. to 2 in. short of valley center.Подпись: WOVEN VALLEY image148

Urethane caulk under closed-cut shingle edges

There are two kinds of closed valleys: woven and closed-cut. Woven valleys offer better protection from weath er but take longer to install. Cld-cU-cut valleys are faster but are pnly one-nhingle-layer thick in the valley center...

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VALLEY FLASHING

Posted by on 13/ 11/ 15

There are basically two types of valleys: open, where the valley’s flashing is exposed, and closed, where flashing is covered by shingles. Each has advantages. Open valleys clear water well, are easy to install, and work especially well beneath wood shingles, shakes, and laminated asphalt shingles, which are thicker and harder to bend than standard three-tab shingles. In woven val­leys, shingles from both roof planes meet in the valley in alternating overlaps and are slower to install, but offer double-shingle protection and are favored for low-slope roofs. And there are variations, such as the closed-cut valley of the two valleys shown in "Closed Valleys,” on p. 73.

Prepare all valley types by sweeping away debris, hammering all sheathing nails flush, and

Lower Roof Corners

then lining...

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Site Work

Posted by on 13/ 11/ 15

Introduction

This Division contains information on site se­lection and on site maintenance and restora­tion during the construction process.

Site Selection

Long before construction begins, you will choose the appropriate site. When the ancient Romans selected a site for housing, they paid careful attention to the health-giving qualities of the land. To test a potential homesite, cattle were confined to graze in the area for a specific period of time, after which they were slaugh­tered and the innards examined. If the animals had unhealthy livers, the site was abandoned.

Unfortunately, the health consequences from the natural conditions of almost any site today pale in comparison to the potential haz­ards created by humans. Keep the following guidelines in mind when choosing a site:

• C...

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Ground Penetrating Radar

Posted by on 13/ 11/ 15

In Ground Penetrating Radar (GPR), electromagnetic waves are sent out from a transmitter on or above the ground surface and picked up by a receiver after pene­trating and returning from the soil. The velocity of the electromagnetic wave propa­gation in soils is dependent on the soil bulk permittivity modulus (Grote et al., 2003). Thus the underlying principles of the GPR soil moisture measurements are the same as those of Time Domain Reflectometry except that in TDR the electromagnetic waves travel along a waveguide whereas with GPR the propagated electromagnetic waves are unconstrained. GPR therefore has the potential to cover a much larger soil volume than does TDR...

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LAND DEVELOPMENT

Posted by on 13/ 11/ 15

Site planning and land development represent major areas of potential cost reduction for most builder/developers. These costs often increase in direct propor­tion to the complexity of local regulations, zoning requirements, and levels of required standards.

It is widely recognized that:

• One of the most rapidly increasing components of housing cost is the cost of land.

• Local governments have most of the control over land availability and use.

Land prices are sensitive to supply relative to demand. Where supply is limited and demand is heavy, the price of developable land rises rapidly...

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Floor

Posted by on 13/ 11/ 15

Подпись: I-Joist

T

he floor is the part of the building with which we have most contact. We walk on the floor and, on occasion, dance, wrestle, or lie on it. We can easily tell if the floor is not level, if it is bouncy or squeaky, and this tells us something about the overall quality of the building. The floor carries the loads of our weight, all our furniture, and most of our other possessions. It also acts as a diaphragm to transfer lateral loads (e. g., wind, earthquake, and soil) to the walls, which resist these loads. Floors insulate us from beneath and often hold ductwork, plumbing, and other utilities. So a floor must be carefully designed as a system that integrates with the other systems of a wood-frame building—the foundation, walls, stairs, insulation, and utilities...

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Shopping Center and Industrial Drives

Posted by on 13/ 11/ 15

Figure 2.57 shows two typical driveway designs to be used as a guide for the design of driveways serving high-volume traffic generators such as shopping centers, industrial plants, industrial parks, and other types of developments having similar traffic charac­teristics. Many of the design features discussed in Art. 2.4.1, At-Grade Intersections, are applicable here. Geometric considerations are as follows:

• Driveways should intersect the highway at an angle between 70 and 90°.

• Each driveway traffic lane should have a minimum width of 10 ft (3.0 m), with 12 ft (3.7 m) preferred.

Shopping Center and Industrial Drives

FIGURE 2.56 Designs for commercial drives. Conversions: 1 ft = 0.305 m, 1 in = 25.4 mm. (From Location and Design Manual, Vol. 1, Roadway Design, Ohio Department of Transportation, with permission)
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EXAMPLES FROM THE DEMONSTRATION PROJECTS

Posted by on 13/ 11/ 15

Подпись: Lacey, Washington Most of the projects in the Affordable Housing Program received some form of fast-tracking processing. In many instances, the city used the program as a test for the improvement and expediting of procedures, and success­ful innovations were frequently adopted for general use.

When Phillips Homes joined the. Affordable Housing Program, a number of changes to the approved plans for their development, The Park, were recommended. Under existing city procedures, approval of the changes would have required a formal hearing by a hearing examiner, and then approval by the city council, with the two steps requiring about two months to complete.

The city manager proposed and the council accepted an alternate proce­dure in which a five-member site _ review committee, whose membership represented var...

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Designing the Aggregate Mix Larger than 2 мм

Posted by on 13/ 11/ 15

Let us design the SMA coarse aggregate fraction (particles larger than 2.0 mm). The majority of guidelines recommend its content should be about 70-80% (m/m) of the whole aggregate mix, making it the major component. It may seem that there is little room to maneuver; however, there is a huge potential for controlling the SMA properties by making changes within this narrow range.

Some issues are worth deliberating, namely the impact on a mix exerted by the following:

• A change in the content of coarse aggregates (grains retained on a 2 mm sieve)

• The actual gradation of the coarse aggregate fraction (distribution of coarse aggregate on sieves larger than 2 mm)

• The density of the coarse aggregate particles

To illustrate these issues, two model mixes of coarse aggregates, calculated...

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Commercial Drives

Posted by on 13/ 11/ 15

The access requirements of most commercial developments can be served by driveways having standard design characteristics. The exceptions are driveways having high traffic volumes, those being used by large vehicles, or those serving businesses that engender unique traffic patterns. For standard commercial drive designs, see Fig. 2.56. The recom­mended radii are (1) 15 ft (4.6 m) minimum, when the through highway is curbed, and (2) 25 ft (7.6 m) minimum, when the through highway is uncurbed. The maximum width is 35 ft (11 m). A dropped curb should be used on curbed streets as shown in section B-B in Fig. 2.50.

Commercial Drives

L 15 ft. or greater.

 

W Not greater than 35ft.

Є 45° to 90°

 
Подпись: 189

R Intersection Radius – Use 40’minimum when existing radius is less than 40′...

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