Blog Archives

With Insulation, a Little Laziness Goes a Long Way

Posted by on 12/ 11/ 15

People naturally think that if you cover 98% of a surface with insulation, you’ll get 98% of the performance. This thinking is horribly wrong. Gaps and missing insulation create a hugely disproportionate performance pen­alty. If you install R-38 batts in an attic but leave 0.5% of the surface area uncovered, you end up with R-32 (16% reduction in R-value). Leave 2% uncovered, and you drop to R-22 (42% reduction). So with 98% cover­age, you get 58% of the performance.

If you run across information saying it’s not cost-effective to add insulation, it probably assumes the initial R-value is what you say it is. In all likelihood, the R-value is less than half what you think, and the upgrade is worth much more—provided it’s done right.

TWO BIG HOLES CAN COST YOU MONEY.

Подпись:With Insulation, a Little Laziness Goes a Long WayDirectly above a bath...

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Terminology

Posted by on 12/ 11/ 15

Pavement sub-surface drainage lies at the boundary of several disciplines each hav­ing their own special terms and notations. The book does not avoid these but, rather, seeks to define them when they are used. To help readers, a “Glossary” is included (Annex C) as well as a list of terms in several languages (Annex B) and a list of symbols (Annex D).

1.5 Conclusion

Water and road construction do not make for a harmonious couple! While water is needed to allow efficient compaction of most of the earthworks and pavement layers and some moisture held in pores can act to develop strengthening suction due to capillarity effects, the overall picture is that water in the road and road sub-structure is undesirable. Water should, if possible, be kept out...

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HAND CUTTING AND SHAPING TOOLS

Posted by on 12/ 11/ 15

Power tools can do a lot, but you often need a hand tool to finish the job.

Chisels clean up the corners of a hinge mortise that a router can’t reach and quickly notch plates so washers sit flush. Be sure to sheathe cutting edges so they stay sharp and don’t cut you when you reach for them.

Mallets can strike chisels without damaging their handles.

Utility knives are indispensable. Quick-blade- change knives dispense fresh blades so you don’t need to unscrew the knife’s body. Don’t use knives with cheap, snap-off blades (often sold at stationery or office-supply stores) to cut construction materials; such blades can break unexpectedly and injure you.

Rat-tail files smooth and enlarge holes and cre­ate an oval slot after two holes are drilled close to each other.

Flat files take burrs off ...

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Try before you buy

Posted by on 12/ 11/ 15

So what do you look for when buying a tool? Well, it helps to remember that tools are not like stretch socks, where one size tits all. A cir­cular saw, for example, may have the right
combination of power and weight but still fed out of balance or awkward when vou hold it.

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A tool that’s not comfortable is like a shoe that is one size too small. It’s never a bargain, regardless of price. A tool that feels good in your hands will most likclv be easvand safe to use. So, whenever possible, try before you buy. Visit home centers and tool dealers that have good selections of tools. Grip the tool to test its balance and feel. If you have small hands, rule out tools that aren’t easv to hold comfort-

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ably. Try the controls and adjustments, too. Use this hands-on information to make vour

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s...

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Loose Cellulose Fibers

Posted by on 12/ 11/ 15

Loose cellulose threads (Figure 4.4) have the longest history of application. One of their advantages is that they become effective immediately after mixing them with aggregate and binder. They should be protected from moisture as they are highly hydrophilic and easily absorb water. Wet fibers are not able to absorb the binder and therefore are not effective.

Loose cellulose fibers are supplied in bags of thermo-shrinkable plastic. The mass of fiber per bag can be prearranged with the manufacturer and should be tailored to the batch volume of a given batch from an asphalt-mixing plant. An automatic

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FIGURE 4.4 An example of loose cellulose fibers. (Photo courtesy of J. Rettenmaier & Sohne GmbH + Co. KG, Germany.)

metering process for SMA production in an asphalt-mixing plant has bee...

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Domestic Waste

Posted by on 12/ 11/ 15

It is estimated that approximately 4 lb of domestic refuse is generated every day for every person in the United States, of which about 3 lb (1.4 kg) per day goes to domestic land-fills and 11 percent is recycled. It is estimated that about 185 million tons (168 X 109 kg) of domestic waste is generated per year in the United States. Several of these wastes have a potential for reuse in highways.

Refuse. Landfill refuse is not sought for reuse in highway construction because there is little homogeneity among landfill refuse, and so a great deal of analysis and separation would be required at individual landfills to determine the potential for use. However, there have been occasions when a highway right-of-way traverses a landfill...

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Binder-Absorbing Additives

Posted by on 12/ 11/ 15

Binder-absorbing additives are the most popular SMA stabilizing agents. The fol­lowing properties are required of a stabilizing material:

• Adequate binder absorbing power—this is the most significant property

• Ability to act without weakening the mixture—the stabilizer must not cre­ate glide planes and lessen the grain-interlocking strength.

Stabilizers of this type occur in various forms related to the following kinds of raw materials: [18]

• Glass—in the form of threads (like fiberglass wool)

• Others—for example, leather waste products (leather dusts)

The crucial difference among stabilizers is their absorbing power. To date, the most effective of the binder-absorbing stabilizers are cellulose fibers...

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Nail Bearing & Nonbearing Walls to Floor Perpendicular to Joists

Posted by on 12/ 11/ 15

Bearing Walls

Three 16d nails or 3" x.131" nails into each joist.

Подпись: Bottom plateПодпись: Joists at 16" O.C. (on center)Nail Bearing & Nonbearing Walls to Floor Perpendicular to JoistsПодпись:Подпись: Subfloor sheathing Nail Bearing & Nonbearing Walls to Floor Perpendicular to JoistsIf wall sits on a rim joist or blocking, place third nail at center of joist space and nail into rim or block.

Nonbearing Walls

One 16d nail into each joist or two 3" x.131" into each joist.

Nail Bearing & Nonbearing Walls to Floor Parallel to Joists

Подпись:Подпись:Подпись:Nail Bearing & Nonbearing Walls to Floor Perpendicular to JoistsПодпись: Nonbearing Walls One 16d nail into each joist or two 3" x .131" into each joist. Nail Bearing & Nonbearing Walls to Floor Perpendicular to JoistsBearing Walls

Three 16d nails or 3" x.131" nails per stud into each joist. If wall rests on a rim joist or blocking, place third nail at center of joist space and nail into rim or block.

Nail Header to Stud

Nail Bearing & Nonbearing Walls to Floor Perpendicular to Joists

4 x 8 or 6 x 8 Header
4 x 10 or 6 x 10 Header

Four 16d nails or 3” x,131" nails

 

Five 16d nails or 3" x,131" nails

— Trimmer (or jack stud) King stud

Nail Bearing & Nonbearing Walls to Floor Perpendicular to Joists

 

Trimmer (or jack stud)

 

4 x 12 or 6 x 12 Header

Nail Bearing & Nonbearing Walls to Floor Perpendicular to Joists

 

Headers made u...

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River engineering and flood protection

Posted by on 12/ 11/ 15

Hydraulic development involved not only the digging of canals, but also the restoration or maintenance of river courses. During the domination of Larsa in lower Mesopotamia (1932 to 1763 BC), it became necessary to rehabilitate the river system. The king Sin – Iddinam reestablishes the course of the Tigris, around 1845 BC, using paid labor:

“When An, Enlil, Nanna and Utu (Sumerian gods) blessed me with a good reign of justice and long days (…), to obtain fresh water for the cities of my country, (…), I fervently prayed to An and Enlil. They answered my fervent prayers and, by their absolute orders, charged me with the mission to dredge out the Tigris, to restore it (into its previous state) and to give the days of a long life to my name...

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Navigation between the Tigris and Euphrates

Posted by on 12/ 11/ 15

The importance of navigable waterways to the economy of Mesopotamia cannot be overestimated. The code of Hammurabi, from which we have already cited several extracts, includes laws that regulate navigation on the rivers and canals. It sets compen­satory payments for shipwrecks or breakdowns, and establishes right-of-way rules:

“If a boat traveling upstream collides with and sinks a boat traveling downstream, the owner of the sunken vessel will officially declare, in the presence of God, all that was lost in his boat, and the boatman of the upstream-traveling vessel that caused the sinking will pay for the boat and everything that was lost.”lz-

Several of the canals flow by gravity from the Tigris toward the Euphrates, reflect­ing the ancient confluence that existed in the IIIrd millen...

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