Blog Archives

Engineered Lumber

Posted by on 12/ 11/ 15

Like any natural product, standard lumber is quirky. It has knots, holes, and splits. And it twists, cups, and shrinks. As mature old-growth timber was replaced by smaller, inferior trees, lumber quality became less reliable—much to the dismay of builders.

In response, the lumber industry combined wood fiber and strong glues to create engineered lumber (EL), including I-joists, engineered beams, plywood, and particleboard. EL spans greater distances and carries heavier loads than standard lumber of comparable dimensions. In addition, EL won’t shrink and remains straight, stable, strong and—above all—predictable.

Still, EL has two main drawbacks: It’s heavy, so dense that it must often be predrilled, and it costs considerably more than sawn lumber. Even so, EL is here to stay.

Подпись: REAL-WORLDПодпись: In an ideal world, every beam is perfectly sized and every purchase is economical. In real life, there's usually a trade-off. Instead of the 2x6 ceiling joists as span charts suggest, a builder may choose 2x10s because they're deep enough to accommodate R-30 attic insulation. Or builders may cut all interior door headers from massive 4x12s because, with 8-ft. stud walls, headers of that depth create the perfect height for standard 6-ft. 8-in. rough openings for doors. And one deep header allows quicker work than if you build headers from 2x lumber and plywood spacers. The same factors apply with engineered lumber: Builders can weigh costs, spans, and loads till the cows come home, but most times they rely on a blend of an engineer's specs, lumberyard recommendations, and their own gut feelings. Подпись: Alternatives to Solid-Wood Joistsimage113"image114

TRUSS...

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BASIC OFFSETS

Posted by on 12/ 11/ 15

Basic offsets are all based on the use of right triangles. You now know about Set and Travel. It is time that you learned about a term known as Run. Travel, as I said earlier, is the distance between center of two offset fittings that cre­ates the length of a piece of pipe. This pipe’s length is determined as it devel­ops from fitting to fitting, traveling along the angle of the offset. When you want to know the Run, you are interested in the distance measured along a straight line from the bottom horizontal pipe. Refer to Fig. 2.4 for an example

Inches

Decimal of an inch

Vf>4

.015625

Mu

.03125

M«4

.046875

VlS

.0625

Мб4

.078125

Mu

.09375

‘/64

.109375

Ms

.125

%4

.140625

Mu

.15625

"/S4

.171875

M,6

.1875

1 ...

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Timber Framing: Advantages and Disadvantages

Posted by on 12/ 11/ 15

Whether you go with “traditional” timber framing (which the Timber Frame Guild likes to call “contemporary timber framing”) or “timber framing for the rest of us,” certain advantages and disadvantages are common to both systems.

Strength. Timber framing by either method is strong. It is not only strong in real structural terms, but it exudes a sense of strength in the architecture. It is hard to visit a half-timbered framed house or country pub in England and not be impressed with the atmospheric power of the structure, a power that owes much of its strength to the visual impact of the beautiful exposed timbers, especially the big old gnarled ones.

Heavy-timber frames, with or without infilling, are more resistant to trauma from earthquakes, wind uplift, and snow load than ligh...

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A final note

Posted by on 12/ 11/ 15

My intention in writing and now in twice revising this book has been to assist designers and builders who are attempting to make beautiful buildings that endure. With the drawings, I have tried to describe the relationship among the parts of every common connection. Alternative approaches to popular details have been included as well. I have relied primarily on my own experiences but have also drawn significantly on the accounts of others. In order to build upon this endeavor, I encourage you, the reader, to let me know of your own observations and critical comments.

Please send them to me care of The Taunton Press,

PO. Box 5506, Newtown, CT 06470-5506 or via email to thallonarch@continet. com.

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Hydraulics of the kingdom of Mari, on the middle Euphrates (IIIrd and IInd millennia BC)

Posted by on 12/ 11/ 15

About 2800 or 2900 BC, the Sumerians – or perhaps a people already established some­what to the north at Terqa – founded Mari, on the middle course of the Euphrates. The site is at the intersection of routes to the Syrian coast, near the outlet of the fertile valley of Khabur. This is not a village that has grown and evolved, but rather a “new city”. The region of Mari is completely arid, no agriculture is possible without irrigation. Yet 200 km to the north, at the toe of the Anti-Taurus mountains, one finds land that is naturally well watered. Therefore Mari must have been established where it is for reasons relat­ed to commerce and control of the waterway. The land of Sumer has to import raw mate­rial such as wood, stone, and metals...

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Water Balance

Posted by on 12/ 11/ 15

For a better understanding of the qualitative and quantitative relationships between water and roads, the general interaction of road to water should first be established. The approach adopted here for this interaction analysis is by considering the water balance.

The relation between a road and water can be defined in system theory terms where input and output values are observed. Thus, the road and its pavement can be defined as a system into and out of which water flows. In normal conditions the input to the road pavement is represented by precipitation. Rainfall, or water due to thawing, infiltrates the pavement and flows through into the surrounding environ­ment. Reverse flow of surface or groundwater towards the pavement embankment is also possible.

The general water balance equatio...

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Between the Middle Euphrates and the Syrian coast: dams and canals from the IVth to the IInd millennium BC

Posted by on 12/ 11/ 15

The mysteries of Jawa: the oldest known dams, on the slopes of Kjebel Druze (Djebel el Arab) – end of the IVth millennium BC

The site of Jawa, a hundred kilometers to the northeast of Amman in Jordan, is an enig­ma. It is an arid zone, in a desert of rough black basalt. The only source of water, apart from very infrequent rains, is the winter flood of a seasonal watercourse that comes down from Djebel Druze, the wadi Rajil. The site is somewhat off the track of commu­nication routes, but on the other hand it is easily defendable. Jawa had some 2,000 to

3,0 inhabitants toward the middle or the end of the IVth millennium BC. In this region [50] [51] where there had never been any settlements before, and where there will not be any new ones for several hundred centuries to come, these peopl...

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Requirements for SMA Materials

Posted by on 12/ 11/ 15

A distinctive feature of stone matrix asphalt (SMA) components is their high quality. In this chapter we shall have a look at the requirements for those materials in various countries. Comparing them may be interesting because of the diversity of emphases different countries place on individual conditions.

Consequently, the following components will be subsequently discussed in detail:

• Aggregates

• Binders

• Stabilizers

• Reclaimed asphalt

• Other additives

5.1 REQUIREMENTS FOR AGGREGATES

The requirements for aggregates are quite diverse, and they chiefly concern fun­damental properties that influence the performance of SMA and are attributed to the size of the grains...

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Preliminary Development Phase

Posted by on 12/ 11/ 15

Two types of projects are considered here: (1) projects that involve studies outside the existing corridor or where a facility for more than one alternative mode of transportation may be involved, and (2) projects where feasible alternatives are limited to the existing corridor but did not qualify to pass directly to the design phase. The main difference between the two as far as processing is concerned is that the first group has not yet narrowed its alternatives down to feasible alternatives.

In each case, a project inventory is developed...

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Framing square

Posted by on 12/ 11/ 15

I learned to use the framing square when I was a carpenter in the Navy in the early ’50s. First introduced almost 1 50 years ago, the venerable framing square is still hard at work. Made of steel or aluminum, it has a 16-in. tongue and a 24-in. blade set at right angles to one another. Not an easy tool to carry in your toolbelt, it is neverthe­less handy for quickly checking if walls are perpendicular to each other when setting cabinets and for marking square across 2×12 joists.

I use small stair gauges with my framing square when laying out stairs (see the photo below). The gauges are simply screw clips that are fastened to the edge

Framing square

Stair gauges attach to a framing square and position it at any given angle.

 

Framing square

When you have a corner that’s out of square, you can ch...

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