Blog Archives

Hanging a Door to an Existing Frame

Posted by on 15/ 11/ 15

Hanging a new or recycled door to an existing frame is a common renovation task, but not always feasible. At the very least, the hinge jamb must be straight. If it’s badly bowed and you can’t draw the bow back with screws, you may need to remove the old frame (and its casing) and replace it with a prehung unit.

Creating a Template

The most reliable way to fit a door to an out-of­square frame is to create a template. (Read "The Beauty of Templates," on p. 317, for some tips.) Use 4-in.-wide, Vs-in.-thick strips of doorskin plywood; tack-staple the plywood strips to the edges of the doorstops the door will seat against. Where they cross, join the strips with fast-setting hot-melt glue...

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Multivariate Probability Distributions

Posted by on 15/ 11/ 15

Multivariate probability distributions are extensions of univariate probability distributions that jointly account for more than one random variable. Bivari­ate and trivariate distributions are special cases where two and three random variables, respectively, are involved. The fundamental basis of multivariate probability distributions is described in Sec. 2.3.2. In general, the availability of multivariate distribution models is significantly less than that for univari­ate cases. Owing to their frequent use in multivariate modeling and reliabil­ity analysis, two multivariate distributions, namely, multivariate normal and multivariate lognormal, are presented in this section. Treatments of some mul­tivariate nonnormal random variables are described in Secs. 4.5 and 7.5...

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Energy Retrofits of All Levels

Posted by on 15/ 11/ 15

Paul Eldrenkamp is a Massachusetts remod­eler who has performed several deep-energy retrofits. When his clients balk at the high cost of a full retrofit, he sometimes advises them to work in phases. Although it is com­mon to perform energy improvements over time as finances permit, it’s also important to take advantage of upgrade opportunities even if they seem to fall out of sequence. For example, if you have to install new siding or roofing and you do so without installing thick rigid foam underneath, you may regret your shortsighted decision in time. Here’s a general overview of the work to be done, the order in which it should be completed, and the practical alternatives to going deep.

ROOF INSULATION

Deep-energy retrofit Many deep-energy retrofits call for insulating a roof to R-60,...

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Water in the Pavement Surfacing

Posted by on 15/ 11/ 15

Andrew Dawson[7], Niki Kringos, Tom Scarpas and Primoz Pavsic

Abstract Pavement surfaces provide a key route of ingress of rain water into the pavement construction. Thus, permeability of asphaltic materials and the water ingress capacity of cracks in the pavement are very important. A range of equipment exists to determine the permeability of asphaltic mixtures both by in-situ and labo­ratory testing. Sometimes porous asphalt surfacing is provided to deliberately allow water into the pavement to limit spray from vehicles and to limit tyre-pavement noise generation. These porous surfaces can become clogged with fines, but reha­bilitating without causing premature damage is a challenge...

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Deflection

Posted by on 14/ 11/ 15

Deflection is similar to bending… but different. Bending concerns us most when it translates into bending failure, which is a bad thing. With deflection, we can tolerate certain amounts of it in certain circumstances. Springiness — or stiffness — in a floor is a characteristic of deflection. Cracking plaster on a ceiling, or separation of taped sheetrock joints, is an indication of excessive deflection.

Deflection is commonly expressed as a percentage or fraction of the span. Two common fractions you will encounter in span tables are V240 and V360 of a span. If a floor sags one inch over 240 inches (20 feet or 6 meters), this is a deflection of V240. A half-inch sag in 180 inches (15 feet or 4.6 meters) is an example of a deflection of V360...

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Recent Research

Posted by on 14/ 11/ 15

Researchers interested in frost action in soils agree on the description illustrated in Fig. 4.3 on how ice lenses grow and cause frost heave. Nevertheless, when it
comes to the degree of water saturation of the unfrozen soil below the freezing front there are two different conceptions. Some researchers believe that the un­frozen soil is fully saturated while others believe it is unsaturated. Of course, these discrepancies in understanding lead to different explanations of the driving force of the capillary rise of water as well as different opinions on how to run laboratory experiments. Andersland and Ladanyi (2004), for example, Konrad and Morgenstern (1980) and Nixon (1991) give equations where it is obvious that full saturation is assumed for the unfrozen soil...

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Ice Lenses

Posted by on 14/ 11/ 15

Frost heaving of soil is caused by crystallization of ice within the larger soil voids. Ice lenses attract water to themselves by the, so-called, cryo-suction process, and grow in thickness in the direction of heat transfer until the water supply is depleted or until freezing conditions at the freezing interface no longer support further crys­tallization, see Fig. 4.3. As the freezing front penetrates deeper into the pavement, the growth of ice lenses ceases at the previous level and commences at the new level of the freezing front. At some point the heat flow will be reduced so that further freezing slows or the weight of overlying construction will impose sufficient stress to prevent further ice lens growth.

Fundamentally, the so-called cryo-suction process results from the consequences...

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The Payback

Posted by on 14/ 11/ 15

Homeowners who undertake deep-energy retrofits are usually motivated by environ­mental or energy-security concerns rather than a desire to save money on their energy bills. These jobs are so expensive—in the range of $50,000 to $150,000 per house— that a homeowner would have to wait decades before the investment could be recouped. "In a retrofit situation, it can cost a lot of money to save a small amount of en­ergy," says energy consultant Michael Blas – nik. "Going from R-19 to R-40 walls or R-30 to R-60 ceilings doesn’t save a whole lot of Btu—and the cost of that work is potentially tremendous."

There’s no easy way to calculate the payback period for many deep-energy ret­rofits, in part because a major overhaul of a building’s shell inevitably includes many measures (for exampl...

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Physics of Frost Heave

Posted by on 14/ 11/ 15

3.4.1 Frost Heave and Spring Thaw

Frost heave occurs in roads having fine graded, so-called frost-susceptible, mate­rial, at a depth to which the freezing front reaches during the winter. A well-built road of consistent materials and cross-section can be expected to heave relatively evenly. When inconsistencies or inhomogeneities are found in the construction of the affected subgrade, then frost heave is likely to be uneven and may well cause an uneven road surface that results in reduced travelling speed and comfort.

Although such heave can be problematic, a much greater problem usually arises in spring-time when the ice that has formed in the road construction, which was instrumental in causing the frost heave, melts and results in a very high water content in the pavement and subgrade...

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STEP 2 PLATE THE WALLS

Posted by on 14/ 11/ 15

This step involves laying out all of the lumber required for the top and bottom plates, cutting the plates to length, and temporarily tacking them on their layout lines so that matching marks can be made on both plates for the studs, doorways, windows, and intersecting walls. Don’t plate, mark, and build one wall at a time. This old method is time-consuming and makes it difficult to frame accurately. Instead, put all the plates down for every wall, beginning with the outside walls.

It’s best to plate the long, outside through walls first, then plate the outside butt walls that extend between the through walls. As shown in the illustration on the facing page, through walls have plates that run through from corner to corner...

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