Load bearing v framed - 1 Q3 - Estate Agent's Examination Part 1&2

Q.
a) Explain the term "load bearing wall building" and "framed building" (8 marks)

b) State the differences of these two (2) types of building structures. (7 marks)

c) Describe the types of building structures that are commonly used in the housing project development in Malaysia. (10 marks)

(25 marks, 2014 Q3)

A.
A load-bearing wall (or bearing wall) is a wall that bears a load resting upon it by conducting its weight to a foundation structure. The materials most often used to construct load-bearing walls in large buildings are concrete, block, or brick.

When a load bearing wall is constructed high enough to subject to lateral forces, it can topple down. Hence, the ancient architecture of flying buttress is designed to hold the verticle load bearing wall from toppling down outwards. The purpose of these buttresses are to resist the lateral forces pushing a wall outwards (which may arise from stone vaulted ceilings or from wind-loading on roofs) by redirecting them to the ground.

Flying buttress

This limitation is later on challenged by the birth of skyscrapers. How was that possible?

By the used of "Framing".

Framing, in construction is the fitting together of pieces to give a structure support and shape[1]and sometimes is used as a noun such as "the framing" or "framing members". Framing materials are usually wood, engineered wood, or structural steel.

Building framing is divided into two broad categories,[2] heavy-frame construction (heavy framing) if the vertical supports are few and heavy such as in timber framing, pole building framing, or steel framing or many and smaller called light-frame construction (light framing) including balloon, platform and light-steel framing. Light-frame construction using standardized dimensional lumber has become the dominant construction method in North America and Australia because of its economy.

Use of minimal structural materials allows builders to enclose a large area with minimal cost, while achieving a wide variety of architectural styles. Historically mankind fitted naturally shaped wooden poles together as framework and then began using joints to connect the timbers, a method today called traditional timber framing. Timber framing was superseded by balloon framing beginning in the 1830s in America which is made up of many light-weight wall members called studs rather than using fewer, heavier supports called posts, and was nailed together rather than using joinery.

The studs in a balloon frame extend two stories from sill to plate. Platform framing superseded balloon framing and is the standard wooden framing method today. The name comes from each floor level being framed as a separate unit or platform.

Modern light-frame structures usually gain strength from rigid panels (plywood and other plywood-like composites such as oriented strand board (OSB) used to form all or part of wall sections) but until recently carpenters employed various forms of diagonal bracing to stabilize walls. Diagonal bracing remains a vital interior part of many roof systems, and in-wall wind braces are required by building codes in many municipalities or by individual state laws in the United States. Special framed shear walls are becoming more common to help buildings meet the requirements of earthquake engineering and wind engineering.

The alternative to framed construction is generally called mass wall construction which is made from horizontal layers of stacked materials such as log building, masonry, rammed earth, adobe, etc.

Steel Framing

Steel frame usually refers to a building technique with a "skeleton frame" of vertical steel columns and horizontalI-beams, constructed in a rectangular grid to support the floors, roof and walls of a building which are all attached to the frame. The development of this technique made the construction of the skyscraper possible.

The rolled steel "profile" or cross section of steel columns takes the shape of the letter "I". The two wide flanges of a column are thicker and wider than the flanges on a beam, to better withstand compressive stress in the structure. Square and round tubular sections of steel can also be used, often filled with concrete. Steel beams are connected to the columns with bolts and threaded fasteners, and historically connected by rivets. The central "web" of the steel I-beams is often wider than a column web to resist the higher bending moments that occur in beams.

Steel framing

Ref:
Wikipedia on "Load Bearing Wall" "Flying buttress" "Framing" and "Steel Framing"
http://en.m.wikipedia.org/wiki/Load-bearing_wall
http://en.m.wikipedia.org/wiki/Flying_buttress

http://en.m.wikipedia.org/wiki/Framing_(construction)
http://en.m.wikipedia.org/wiki/Steel_frame