Offset and Side-post Umbrellas
Offset Means "Support By Horizontal Arm"
Patio umbrellas used for outdoor shades are usually set on a vertical central pole. Newer umbrellas can have a pole with a double-joint, which allows the direction of the arm holding the umbrella to be adjusted.
This means that the position of the stand can be set to the side slightly, which moves the center pole away from the view of those under the umbrella. These are also known as offset umbrellas as the support arm is angled away from the central post.
A Flexible, Versatile Support Arm
The arm which holds the offset patio umbrella has enormous range of motion, going from vertical to horizontal. Several companies offer offset and side-post umbrellas, such as Baja and Sorrento. The size of the offset umbrella can vary greatly, with some as large as 8 to 10 feet in diameter. Be aware that there is a big difference in quality fo fabric, as well as the dye of the fabric. Lower quality dyes will not last long due to constant, intense sun exposure but higher quality ones will prove durable over many years of use. The reaosn for this is because the UV rays of sunlight are perfect for breaking down the molecular structure of dyes.
Traditional umbrellas block the view of people underneath
Conventional Frame Materials
Most offset umbrellas are composed of fabrics supported by wooden, vinyl or steel supporting ribs. These can break or bend permanently due to powerful winds in storms. A more robust material, but one that isn't compromised by enormous weight, would be very useful in manufacture of offset umbrellas that do not break so easily, and yet can absorb the stresses of strong winds. Fiberglass is one such material. Fiberglass is a mixture of glass, which is very strong, and plastic polymers, which are very flexible.
Unconventional Frame Material
The outcome is an extremely robust material that is perfect for supporting fabrics. Think of surf boards, kayaks, even car parts and home doors, which can all be made of fiberglass. These are light but tough producs. Fiberglass offset umbrellas can withstand winds of up to 50 miles per hour (or 80 kilometers per hour). The drawback is that these are a bit more expensive than regular side-post umbrellas. Another advantage is that fiberglass materials are in general resistant to mold, fungus, and rust which can afflict wood or metal frames. Moreover, fiberglass is such a versatile material, it can be crafted to mimic other materials for aesthetic reasons.
Offset Umbrella Bases
Why stop at customizing an offset umbrella with just the fabric and pole selection? The base of the offset umbrella is an important point to consider also. Remember that strong winds can topple many side-post umbrellas especially if the base is too light weight. Ensure it is stable and safe for the family or guests by purchasing a base of adequate weight. Umbrella stands sometimes provide additional functionality, such as attachment to a table at which people can sit to be under it. How much does a typical base weigh? Well, the bases can range from a lightweight 20 pounds to something as heavy as 70 pounds. A lot of this also depends on the size of the umbrella, which adds considereable weight. Materials for bases are as varied as cast iron, polymer resins, to concrete.