Blog Archives

INSTALLING FRIEZE BLOCKS BETWEEN. RAFTERS AND TRUSSES

Posted by on 17/ 11/ 15

Подпись:Подпись:Подпись: RafterПодпись: When installed perpendicular to the rafters, blocking provides a stop for other types of siding.INSTALLING FRIEZE BLOCKS BETWEEN. RAFTERS AND TRUSSESINSTALLING FRIEZE BLOCKS BETWEEN. RAFTERS AND TRUSSESINSTALLING FRIEZE BLOCKS BETWEEN. RAFTERS AND TRUSSES

2x frieze block

Rafter

Double top plate

Stucco

When installed plumb, a frieze block provides backing for stucco.

2x frieze block

Siding

Trusses by themselves are rather fragile. They gain strength when they’re properly blocked and braced. I will now explain various blocking and bracing strategies, because this work needs to be done as the trusses are installed.

Hurricane clips and frieze blocks

A hurricane can tear a roof completely off a house. Hurricane clips, which are designed to prevent this, are required by code in some parts of the country. After the trusses are nailed in position, hurricane clips are easy to install from inside or outside the house. Drive nails into the trusses and the top plates of the wall (see the bottom left photo)...

read more

Dissolution/Precipitation

Posted by on 17/ 11/ 15

Rainwater is able to dissolve gas present in the atmosphere (leading to acid rain, for example; see Section 6.2.6). Rainwater is also able to dissolve chemicals present at the road surface (e. g. metals, salts and some organics). Road materials are of course selected for not being soluble but trace elements present in natural and alternative materials can be released by dissolution when leached by seepage. The rise in a water table can also bring about dissolution. Dissolved elements can precipitate downstream where hydrous, pH and/or redox conditions differ from those upstream. Dissolution/precipitation sequences are also part of the circulation of chemicals...

read more

Advanced First-Order Second-Moment (AFOSM) Method

Posted by on 17/ 11/ 15

The main thrust of the AFOSM method is to improve the deficiencies associated with the MFOSM method, while keeping the simplicity of the first-order approx­imation. Referring to Fig. 4.3, the difference in the AFOSM method is that the expansion point x+ = (xL*, xR+) for the first-order Taylor series is located on the failure surface defined by the limit-state equation, W(x) = 0. In other words, the failure surface is the boundary that separates the system performance from being unsatisfactory (unsafe) or being satisfactory (safe), that is,

{

> 0, system performance is satisfactory (or safe region);

= 0, limit-state surface (or failure surface);

< 0, system performance is unsatisfactory (or failure region).

The AFOSM method has been applied to various hydrosystem engineering prob­lem...

read more

The future of the discoveries of the 3rd century BC

Posted by on 17/ 11/ 15

As we have shown, Lagide Egypt undergoes a period of troubles and reduced prosperi­ty from the 2nd century, a situation not at all propitious for development. Ptolemy VIII (called Physcon – i. e. the vain) hunts down the Alexandrian intellectuals in 145 BC and later sends his mercenaries to attack this city that had revolted. Far from being lost, the discoveries of the 3rd century BC reappear in the hydraulic projects that we are going to describe subsequently. They comprise a patrimony shared by the Roman engineers and the scientists of the school of Alexandria from the first centuries of our era – the school poised for another fruitful period under Roman domination.

The implementation of new hydraulic technologies in the Hellenistic kingdoms, from the 3rd to 1st century BC

Even though P...

read more

Ridgen’s method modified by Anderson

Posted by on 17/ 11/ 15

The U. S. method (here called Rigden-Anderson) described in Anderson (1987) stipulates 25 strokes of the 100 g dead weight. Results of the measurements form the basis for calculating the volume of air voids in a dry compacted filler. Only 1.0-1.3 g of filler is needed to conduct the testing. After determining the content of air voids in the compacted filler, the calculation of free and fixed binder may be per­formed (by mass and by volume). The concept of free and fixed binder is presented in Chapter 3.

8.3.2.2 comparison of methods

Rigden’s method (the European procedure) and Ridgen’s as modified by Anderson (the U. S. procedure) produce different contents of air voids in the same compacted [54] filler. This is caused by a lower compacting effort in the U. S...

read more

Determination of Compacted Filler Air Voids after. Rigden’s and Rigden-Anderson’s Methods

Posted by on 17/ 11/ 15

Rigden’s and Rigden-Anderson’s methods apply to any fine material used as a filler in hot mixes (e. g., bag-house fines and added filler). Filler air voids make up an air volume occurring among grains of filler compacted with a special apparatus by a standardized method. Test methods according to the EN standard (Rigden) and the U. S. procedure (Rigden-Anderson [Anderson, 1987]) differ markedly, which makes the direct comparison of results impossible. The only feature they have in common is their principle—dry compaction of filler.

8.3.2.1 Rigden’s Method after EN-1097-4

The EN method provides for compaction of a dry sample of filler by 100 strokes of a dead weight every second. The mass of sample is 10 g, and the mass of the dead weight is 350 g.

The volume of air voids is estimated...

read more

Techniques SHEATHING A WALL

Posted by on 17/ 11/ 15

WHEN ALL THE walls have been raised, braced, and lined, it’s time to attach the sheathing. On this house, two types of sheathing are used.

1. To provide shear bracing, OSB panels are installed on all corners and every 25 ft. along exterior walls.

2• Foam board sheathing is nailed to the framing between wood panels. It’s easier to sheathe right over window and door openings, then cut out the openings from inside. Foam cuts easily with a handsaw.

Techniques SHEATHING A WALL

Safety on the Job LADDERS

FEW THINGS SCARE me more than working on a ladder. While they are frequently indispensable, ladders must be treated with the same respect as power saws. Here are a few tips to make working on a ladder safer:

ж Don’t buy a cheap ladder. I like the heavy-duty, fiberglass models...

read more

WORK SAFELY ON A ROOF

Posted by on 17/ 11/ 15

Keep your wits about you and pay extra attention to what you’re doing when you’re up on a roof—both to keep yourself safe and to ensure that the integrity of the roof is not compromised. To get on and off the roof, use a good, sturdy ladder that extends 3 ft. above the edge of the roof.

■ Keep the roof clean so that there won’t be anything to trip over.

■ Be careful when sawdust is on the roof. Sawdust on a sloped roof can be as slick as ice. To be safe, call out measurements to cutters on the ground and have them clear the board of sawdust before handing it up to you.

■ Never throw anything off a roof, not even a shingle, without first checking to see that no one is down below.

■ In the hot sun, asphalt shingles soften and tear.

Walk gently so you don’t damage the shingles...

read more

Channel and Shore Protection

Posted by on 17/ 11/ 15

Highways are often located adjacent to streams, lakes, and coastal areas. Channel and shore protection must be provided wherever the need is apparent or the risk is high.

In other circumstances, where the possibility of damage to the roadway or adjacent land is not clear or risk is low, it may be acceptable to delay construction of embank­ment stabilization measures until a problem actually develops.

There are a number of methods of protecting the roadway from damage due to ero­sion. The simplest and surest of these is to locate the highway away from the erosive forces. This should always be considered, although it is rarely the most economical alternative...

read more

STEP 8 Install and Plumb Door and Window Trimmers

Posted by on 17/ 11/ 15

Many builders—even experienced ones— don’t like to spend time plumbing window and door trimmers. But Lve found that this step really makes a better building. If the door

1. Drive this nail first, then bend it over, embedding the shank and head in the adjacent board. [1]
trimmers are plumb, the doors hinge-side

jamb butts solidly against the trimmer along

its entire length. Thercs no need for shims on

this side of the door. That means vou save

/

time and obtain solid, continuous backing for the jamb that supports the full weight of the door. If the opposite trimmer is also plumb, the shims vou install can share the same thick-

г

ness. There’s no fussing to make shims of dif­ferent sizes. Similarly, window installation benefits from plumb trimmers.

Window trimmers were installed during ...

read more