Inappropriate use of ladders is the number one cause of falls. Ladders are used so often in framing that it is easy to overlook basic safety guidelines. Always remember the following: • The feet of the ladder need to be on a stable surface so the ladder will be level. • When ladders are used […]
Rebates and Tax Breaks Could Be the Keys to the Future
What takes the sting out of the high cost of buying into renewable-energy systems is a combination of federal tax credits and state and utility rebates. The federal credit, pegged at 30% of system cost, is open to everyone. State and utility rebates, however, vary. Where they are generous, such as in California or Hawaii, […]
Seasonal Variation in Pavement Design and Analysis — Some National Examples
A.1 Introduction The primary objective of this annex is to present examples of how moisture condition is taken into account in pavement design and analysis. The pavement design regarding the influence of water has significantly different objectives in different European countries. While in central and northern Europe the most important question is how to protect […]
Steps in Construction of FAST Diagrams
The following steps are recommended in the construction of the FAST diagram: 1. Function listing. Prepare a list of all functions, by assembly or by system, using the verb-and-noun technique of identification of function. Do this by brainstorming the questions (a) “What does it do?” and (b) “What must it do?” 2. The function worksheet. […]
Future Performance
The observation of climate changes, as a consequence of global warming, reveals the aggravation of extreme situations, including alternating torrential rain periods with drought situations. Therefore, it’s important to ensure that road drainage systems are calculated for extraordinary phenomenon (both precipitation and flow) associated with a predetermined return period, which includes an allowance for the […]
Innovation
The legacy of Alexander is somewhat mixed insofar as innovation is concerned. To his credit there is the city of Alexandria, with its cultural diversity and intellectual fertility. Of course there is also Archimedes, founder of hydrostatics and supposed inventor of the “Archimedes screw”. There is also Ctesibios, inventor of the fire pump. But other […]
Using Solar for Space Heating
Solar collectors are commonly used for domestic hot water, but they also can supplement both forced-air and hydronic heating systems. In Europe, says Tim Merrigan of the National Renewable Energy Laboratory in Boulder, Colo., package systems that do both are relatively common. But due to heavy winter-heating loads and reduced solar potential, homeowners in this […]
WHOLE-HOUSE BACKUPS
Whole-house backups (where none of the plumbing fixtures drain) indicate either a problem in the building drain, the sewer, or the septic system. There is no way to know where the problem is until some investigative work is done. It’s possible that the problem is associated with the septic tank, but you will have to […]
How Much Hot Water Do You Need?
Most Americans use about 20 gal. of hot water a day, a standard industry benchmark. Most hot-water tanks are sized for a single day’s consumption, so an average family of four, for example, might end up with an 80-gal. tank. Solar hot-water systems shouldhave no trouble delivering that kind of volume, but there aren’t any […]
Wood Flooring over Concrete
Before purchasing wood flooring for installation over concrete slabs or in subgrade areas, check the flooring warranty to see if subgrade installations are allowed. If so, be sure to correct excess moisture conditions beforehand. In general, engineered wood is a better choice than solid-wood flooring in such locations because engineered wood’s cross-ply construction is more […]