Blog Archives

DISTANCE FROM TRAP TO VENT

Posted by on 15/ 11/ 15

The distance from a trap to a vent is determined by local plumbing code re­quirements. Allowable distances are usually given either in text or in tables within a codebook. There can be a sig­nificant difference from one code to the other. To illustrate this, I’d like you to refer to Figures 5.18, 5.19, and 5.20. The tables you see in these illustrations represent differences between three major plumbing codes. You should no­tice that the distances from traps to vents is the same for two codes and dif­ferent for one code. You must refer to the plumbing code that is being en­forced in your area for specific sizing requirements...

read more

Slab and Stem Wall Treatment and Detailing

Posted by on 15/ 11/ 15

Concrete can act as a wick for ground mois­ture, thereby promoting water damage and fungal growth in other materials through moisture transfer. A layer of coarse gravel under the slab with no fines smaller than half an inch will break capillary action. A layer of continuous, unpunctured polyethylene di­rectly under the slab will help prevent water vapor and soil gases such as radon from find­ing their way through cracks in the slab. A fully cured slab can also be sealed to further prevent moisture and soil gases from enter­ing the building and to create a more finished floor surface. Some sealers are solvent based and should be avoided. The following sealers are more benign:

• AFM Safecoat CemBond Masonry Paint:

Water-resistant coating for cement, con­crete block, and masonry

• AFM ...

read more

Computation of multivariate normal probability

Posted by on 15/ 11/ 15
Подпись: Ф( z | Rx ) = P (Z1 < Z1, Z2 < Z2, ■■■ , ZK < ZK | Rx ) Computation of multivariate normal probability Подпись: <£( z | Rx) dz 0 (2.116)

Evaluation of the probability of multivariate normal random variables involves multidimensional integration as

Accurate evaluation for Ф(г |Rx) is generally difficult and often is resolved by approximations.

Подпись: L(a, b | p) = L Computation of multivariate normal probability Подпись: + L b,0 Подпись: (pb - a)(sign b) /a2 - 2pab + b2

Bivariate normal probability. For abivariate case, Fortran computer programs for computing the lower left volume under the density surface, that is, Ф(а, b | p) = P(Z1 < a, Z2 < b | p), have been developed by Donnelly (1973) and Baughman (1988). The double integral for evaluating the bivariate normal probability can be reduced to a single integral as shown in Eq. (2.111). Sev­eral approximations have been derived (Johnson and Kotz, 1976). Derivation of bounds for the bivariate normal probability is presented in Sec. 2.7.3...

read more

REQUIREMENTS FOR AN SMA MIXTURE DESIGN

Posted by on 15/ 11/ 15

Volumetric properties are among the most frequently cited requirements for SMA mixtures checked at the laboratory level. The primary requirement is to ensure the needed content of voids in compacted samples. Mechanical requirements (e. g., stability) are seldom determined, whereas performance-related properties (e. g., resistance to rutting) can be more often seen in specifications. Table 6.13 shows a short summary of different types of requirements. The corresponding summary of requirements for SMA in accordance with the European classification system after EN 13108-5 can be found in Chapter 14.

Requirements for laboratory-designed SMA mixtures according to the European standard EN 13108-5 can be found in Chapter 14 (see Table 14.3).

Upon completing the design of an aggregate mix and the ...

read more

In-Situ Infiltration Measurement

Posted by on 15/ 11/ 15

Because cracks play such an important part in allowing water to enter a pavement through the surfacing, laboratory assessments of the permeability of intact asphaltic mixtures are not overly useful. Therefore, a range of techniques have been developed to assess permeability by infiltrating water into the pavement surface from a device which acts over a limited area of the surface (e. g. Ridgeway, 1976; Cooley, 1999; Fwa et al., 2001; Taylor, 2004; Mallick & Daniel, 2006). Used randomly on the surface, the infiltration observed will be likely to relate to the mean value – be­ing a combination of water entering through intact material and via degradation cracks induced by compaction, by the environment or by traffic...

read more

Replacement Windows

Posted by on 15/ 11/ 15

If existing sashes have deteriorated and you’d like to avoid the major headache of ripping out existing frames, casing, finish surfaces, and siding, then replacement windows can be a cost-effective solution. These units come encased in frames, which you insert into existing wood frames, after removing the old sashes and pulling the parting beads so that old jambs are reasonably flat. Just cut the sash cords and leave old sash weights in the wall.

Start by measuring the existing window frames carefully, because replacement units fit snugly inside them. Old frames are frequently out of square, even if their jambs are parallel. Thus, in addition to measuring height and width, note which way a frame leans, so you can order the biggest rectangle that will fit into that opening...

read more

STEP4 Mark the Plates

Posted by on 15/ 11/ 15

Building walls is like baking a cake. Success depends on having all the right ingredients. When you mark the plates, you’re setting the exact locations for all of the headers, cripples, studs, corners, and wall intersections associ­ated with each wall in the house.

Mark corners and channels first

When marking up each plate, start with the locations of corners and wall intersections, which are referred to as channels or tees (see the illustration below). As well see shortly, corners and channels require extra studs so that the walls can be properly nailed together once they are raised. The extra studs also provide backing for drywall. Use a channel marker to mark corners and channels on the plates. Store-bought aluminum markers arc available, as shown in the photo at left on the
facing page...

read more

Method 3: Build and Chalk Lines

Posted by on 15/ 11/ 15

This method is possibly the quickest way to figure stud heights and build rake walls. Here is how it is done:

• First, lay out the bottom plate in the same way you would if you were going to frame an ordinary wall.

• Spread your studs, making sure that they are long enough to reach the top of the rake wall.

• Toenail the bottom plate from the inside of the plate so that when the wall is lifted, the nail will function as a pivot point on the layout line.

• Cut the length of the beginning stud to match the adjoining wall. Take into consideration the location of the rafters if the lookouts rest on the rake wall, and the thickness of the plates on the rake.

• Set the beginning stud square with the bottom plate.

• Use the rise percent to find the length of the longest stud...

read more

DESIGNING A BINDER CONTENT

Posted by on 15/ 11/ 15

Selecting the binder content in a design SMA mixture is relatively easy. With a cor­rectly designed aggregate mix, it is enough to remember an appropriate content of voids in compacted samples. A thorough understanding of that subject will surely be made much easier by reading Chapter 7, including the description of both the U. S. and Dutch methods, and the section in Chapter 8 on preparing samples.

The majority of SMA guidelines have stipulated minimum contents of binder for a specific SMA mixture, and a limitation on the maximum quantity of binder has occasionally appeared. In each case, it should be kept in mind that these limits have been introduced in relation to the expected density of an aggregate mix (see Section 6.3.1.4).

Designing the binder content in SMA is the next stage of w...

read more

Framing Rake Walls

Posted by on 15/ 11/ 15

Framing Rake WallsПодпись:

There are four common ways to figure stud heights and build rake walls.

1. Chalk lines on the floor.

2. Figure lengths on paper.

3. Build and chalk lines.

4. Stick frame.

Each has its own advantages. With all these methods, you must use the pitch given in the plans to determine the wall height. The pitch is generally shown on the elevation sheet just above the roof slope.

Method 1: Chalk Lines on the Floor

The first method is to chalk out a duplicate on the floor, if you have the space. Then you can measure and cut the studs and plates right from your chalk lines.

The advantage to using this method is that it is quick, easy, accurate, and doesn’t require a lot of math...

read more