Post-Tension Slab Foundations

Post-Tension Slab FoundationPost-tension slab foundations are found in newer homes. Here in the Bay Area, a structure’s foundation needs to withstand not only the load of the building, but expansive soils, and the ubiquitous earthquake. Certain foundations are better at handling these conditions, and are seen more frequently here. One of these which is gaining popularity in new construction is the post-tension slab foundation.

What is a Post Tension Foundation?

Post-tensioning is a technique that was developed and first put to regular use in the 1970s, and approved methods have been published by the Post-Tensioning Institute (PTI), a nonprofit organization, since 1976. Sometimes called post tensioning, or simply PT, this is a type of slab foundation with added reinforcement.

In essence, a slab foundation, aka a slab on grade foundation, is a concrete base only a few inches deep, sitting directly on earth. You might see this for a small shed or playhouse, but larger structures are almost always reinforced, usually with rebar, and a fabric water barrier is lain out before the concrete is poured.

A post-tension slab is reinforced with grids of steel cables cased in plastic sheathes instead of rebar. After the concrete has hardened around them, the cables are pulled taut with hydraulic stressing jacks. This pre-stressing of the concrete creates added compressive strength to the foundation.

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Myths and Misconceptions about Buying a New (or Newer) Home

Many Silicon Valley home buyers prefer to purchase a brand new home, or at least a younger one.  (Through my web tools, I that see a lot of people search online for “New San Jose Homes” or “New Los Gatos Houses for sale” or “new construction in Silicon Valley”.)

Often this is partly because real estate consumers believe that a more contemporary home will be better structurally and have nicer amenities – those are often true. (New home construction may include better materials, a more open floor plan, walk in closets and other features that are not so commonly found in resale properties.)

Just as frequently, though, a priority for these home buyers is that they expect that a new home will require little or no maintenance.  Further, some buyers are so confident in the perfection of a new home that they decline the chance to have the new home professionally and independently inspected.

Finally, some consumers are so blinded by the love of new (or remodeled) housing that they aren’t very selective and sometimes view all contractors or builders as equal.

All of these are mistakes and today I want to discuss each one.
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