Blog Archives

Drive Profile Design

Posted by on 13/ 11/ 15

Drive profiles on uncurbed roadways should slope down and away from the pavement

edge at the same slope as the graded shoulder. Any vertical curve should be developed

Drive Profile Design

FIGURE 2.57 Designs for shopping center and industrial 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)

outside the normal graded shoulder width. Vertical curve lengths should be 10 to 20 ft (3.0 to 6.1 m), depending on the grade differential. Under normal circumstances, rural drive grades should not exceed 10 percent, with 8 percent the preferred maximum.

The drive profiles for curbed roadways were developed using the design vehicle described in Fig. 2.50...

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Capacitance Measurements

Posted by on 13/ 11/ 15

Capacitive sensors measure the resonant frequency of an inductance-capacitance (LC) tuned circuit where the soil located in between two flat waveguides is the dielectric material. The inductance is kept constant and the resonant frequency f measured and therefore the capacitance can be calculated from

2n ^ e

where Le is the inductance and Ce is the capacitance. The capacitance Ce is a measure of the relative bulk dielectric constant of the soil and is a function of the water content of the soil (Veenstra et al., 2005). As with all dielectric moisture-based sensors, calibration is necessary for an accurate determination of the water content. Starr and Paltineanu (2002) give an overview of the current capacitance methods, their instrumentation and procedures.

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Nail rim joists first

Posted by on 13/ 11/ 15

Rim joists form the exterior of the building and are the first joists to he installed. The lay­out of other joist locations are marked on the top edges of the rim joists. Cut the rim joists to length and toenail each one flush with the outside of the sill. I drive one I6d nail every 16 in. around the perimeter (see the photo below). In earthquake and high-wind areas, code may require that the rim also be secured to the sill with framing anchors, so check with
your local building inspector. If there are no vents in the foundation, they can be cut into the rim joists. A standard screened vent fits in a 41^-in. by 14^-in. opening.

If you’re framing a floor with 1-joists, you’ll probably use the specially made OS В rim joists supplied with your I-joist order...

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POTABLE WATER SYSTEMS CALCULATIONS

Posted by on 13/ 11/ 15

  POTABLE WATER SYSTEMS CALCULATIONS

When you are dealing with large buildings, there will usually be detailed riser diagrams, blueprints, and specifications available to outline your work. House plans rarely show much more than fixture placement for plumbing. They frequently have wiring diagrams, but most don’t show a piping schematic. Long story short, commercial build­ings are usually laid out for the master plumber by a designer.

 

water service or a 1-inch water service into the building. Primary piping would be three-quarters of an inch in diameter, with branch piping having a diameter of one – half an inch. A rule of thumb is that not more than two fixtures should be served off of a single half-inch branch. This is a simple system without much of a load...

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Safety on the Job PNEUMATIC NAILERS

Posted by on 13/ 11/ 15

Safety on the Job PNEUMATIC NAILERS

FOR THE MOST PART, volunteers who help build Habitat houses use only hammers to drive nails. But these days, buildings are often nailed together with all kinds of pneumatic nailers. These tools have been around for 40 years or so and are generally good, reliable tools. Models are available for framing, fin­ish work, siding, and shingling. However, as with all power tools, there are basic safety considerations to keep in mind.

♦ Treat a pneumatic nailer with respect. Be mind­ful of what you are doing. Never point a nailer at yourself or at others.

♦ Read and follow the instruction manual regarding

its maintenance and use.

♦ Don’t walk around with your finger on the trigger. You could bump the nailer against your leg, releasing the safety and accidentally firing a nail.

♦ Adjust the air p...

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RUNNING THE NUMBERS

Posted by on 13/ 11/ 15

Running the numbers of pipe fitting is not always necessary to complete a job. If you have the experience and the eye to get the job done, without going through mathematical functions, that’s great. I admit that I rarely have to use sophisticated math to figure out my piping layouts. But, I do know how to hit the mark right on the spot when I need to, and so should you. Accuracy can be critical. If you don’t invest the time to learn the proper methods for figur­ing offsets, you may cut your career opportunities short. Believe me, you owe it to yourself to expand your knowledge. Sitting still can cost you. Reach out, as you are doing by reading this book, and expand your knowledge.

Some people see plumbers and pipe fitters as blue-collar workers. This may true...

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Supply Ventilation Dilutes Pollutants Throughout the House

Posted by on 13/ 11/ 15

A supply system has the advantage of allowing you to select where the air comes from and how it is distributed throughout your home. For example, fresh air can come from a duct run connected to the return plenum of an HVAC system (see the draw­ing on the facing page). This way, outdoor air is pulled into the house through the air handler whenever it operates. Such an air intake must have controls (such as a timer or cycler) to turn on the air handler to make sure there is enough ventilation air. This sys­tem also should have a damper to prevent overventilating when the heating or cooling system is operating most of the time (very hot or very cold weather). Without these controls, this supply system is just a hole in the return duct, worse than a leaky house.

Supply systems must temper ve...

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Asphalt Shingles

Posted by on 13/ 11/ 15

On residences, two primary types of asphalt shin­gles are used. Until recently, most were three-tab shingles with two slots dividing the exposed part of the shingle into thirds. But today, laminated shingles (also called architectural and dimension­al shingles) are gaining in popularity. Consisting of two bonded layers, laminated shingles are thicker, more wind resistant, and somewhat easi­er to install because they have a random pattern,
with no shingle cutouts to line up. When installed, they look distantly like wood shakes.

MATERIALS: ROUGH NUMBERS

Shingle dimensions vary by maker. Three-tab shingles are typically 12 in. by 36 in. Laminated shingle dimensions are often metric, roughly 13 in. by 40 in. Most shingles are installed with a 5-in...

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WOOD I-JOISTS FOR LOADS

Posted by on 13/ 11/ 15

Squash Blocks & Blocking Panels

WOOD I-JOIST CONNECTIONS

Blocking & Backer Blocks

WOOD I-JOISTS FOR LOADSWOOD I-JOISTS FOR LOADSWOOD I-JOISTS FOR LOADS

Four-by-two wood floor trusses are made up of small members (usually 2x4s) that are connected so that they act like a single large member. The parallel top and bottom chords and the webs are made of lumber held together at the intersections with toothed metal plates.

The open web allows for utilities to run through the floor without altering the truss. Round ducts from 5 in. to 16 in. in diameter can be accommodated, depending

on the depth of the truss. Truss depths vaiy from 10 in. to 24 in., with spans up to about 30 ft. Like I-joists, floor trusses are practical for long spans and simple plans, but difficult for complicated buildings.

Floor trusses are custom manufactured for each job, and cannot be alte...

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SKYLIGHT AND RIDGE FLASHING

Posted by on 13/ 11/ 15

Skylight flashing is discussed in Chapter 6, where you’ll see an installation from framing to flashing. As a general rule, follow the instructions in the flashing kit provided by the skylight manufacturer.

Traditionally, ridges were flashed with a con­tinuous strip of 12-in.-wide, 30-lb. building paper folded lengthwise, which straddled the ridge and overlapped the top courses of shingles. The build-

Подпись: PRO"ГIP Before inserting counter-flashing, blow or brush out debris from the mortar joints. If your air-compressor hose can reach the roof, use it. Otherwise, insert a piece of plastic tube in the joint and just blow. Wear goggles—and when the tube is in place, don't inhale. 1111 Подпись: 2. This grinder is poised to grind out an old chimney mortar joint. Once the abrasive wheel hits mortar, you'll see nothing but grit. So wear goggles.

Подпись: 4. Finally, run a bead of urethane caulk such as Vulkem® 116 to fill the joint and seal out water. Once the caulk has set a bit, you can tool it with your thumb.

CHIMNEY FLASHING

image156

1. As you roof along a chimney, alternate shingles and L-shaped pieces of step-flashing. Counterflashing will cover the tops of the step-flashing. For extra protection, run a bead of urethane between the step­flashing and the chimney. Press the flashing into the urethane to achieve a positive seal.

image157

3...

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