WHAT ARE THE ADVANTAGES OF VINYL SIDING OVER OTHER TYPES OF SIDING PRODUCTS?
Among all the siding products available to homeowners, none compares with vinyl siding for its lightweight yet durable, maintenance-free features. Vinyl won't rot, chip, flake or blister the way wood siding can and often does. And thanks to new manufacturing innovations and technological advancements, vinyl grains and colors are truer, richer and more authentic than ever before. When it comes to installation, vinyl is still the overwhelming choice of today's builders and remodelers thanks to its ease of handling, availability, durability and lasting good looks. To homeowners, vinyl is the sensible, good-looking alternative to the expense, labor and aggravation associated with whole house painting and yearly exterior maintenance.

Vinyl adds to the resale value of most any home. No other exterior cladding offers such a wide array of grains, finishes, embossing patterns or color combinations.

Performance and Pride
It's not only beauty that can be achieved with vinyl siding. Performance is key when selecting vinyl siding. Protection from the elements – wind, heat, cold, snow, rain – is another feature that should be considered when selecting vinyl siding. Vinyl siding will withstand its beauty over the course of time and is made to protect a home.
http://www.vinylsiding.org/homeowners/why-vinyl-siding-2/#durability

Never Paint Again
Never paint again, music to most homeowners' ears! This is one of the most popular features when selecting vinyl siding as the medium to improve a home. Easy to maintain with a hose and soft cloth, vinyl siding will maintain its beauty for years to come while protecting your home from the elements.

Vinyl Siding Scores Well on Environmental Measures
From raw material acquisition to waste management, vinyl siding scores well in all areas contributing to a "greener" environment. Today's homeowners are more conscious of greener living and energy efficient solutions. Learn more about how vinyl siding contributes to greener living.
http://www.vinylsiding.org/homeowners/why-vinyl-siding-2/#green

Low Total Installed Cost
For all the beauty and durability vinyl siding delivers, what homeowners often appreciate most is its low total installed cost — lower than all other exterior cladding — which is backed by most manufacturers with a lifetime warranty. It’s also inexpensive to maintain because it never needs painting, caulking, or re-pointing; periodic cleaning requires nothing more than a soapy sponge and water.

Vinyl and insulated siding consistently rank among the highest return on investments for remodeling projects.
http://www.vinylsiding.org/homeowners/why-vinyl-siding-2/#value

IS VINYL SIDING WATERPROOF?
Despite common misconceptions, vinyl siding is not waterproof. Thanks to its overlapping profile, a standard interlocking wall of horizontal vinyl panels will effectively shed most rain and water away, providing superior water resistance. However, no vinyl siding is completely impervious to outside moisture from dampness rain or snow. For that reason, siding panels are manufactured with "weep holes" located at the bottom of each panel projection edge. These small but important outlets help channel away water that might find its way inside the siding wall through the panel seams and around moldings, windows, door and fixtures.

Weep holes also allow the infiltration of air, which also helps to dry out the inner surface of the siding while promoting evaporation of any remaining moisture. The application of house wrap and or insulation board also provides for a secondary defense against outside moisture that might penetrate the siding and come in contact with the original sheathing.

DO I NEED A HOUSE WRAP?
Yes. It was introduced in 2009 as part of the International Residential Code 2009 IRC code:

R703.1.1 Water resistance.
The exterior wall envelope shall be designed and constructed in a manner that prevents the accumulation of water within the wall assembly by providing a water-resistant barrier behind the exterior veneer as required by Section R703.2 and a means of draining to the exterior water that enters the assembly. Protection against condensation in the exterior wall assembly shall be provided in accordance with Section R601.3 of this code.

MY SIDING IS NOT FIRMLY ATTACHED TO THE WALL, WHY?
Vinyl siding is never "attached to the wall," rather it is "hung on the wall." The difference is what separates a professional installation from a problematic one. One of the inherent properties vinyl siding is its thermal expansion properties. Vinyl expands as temperatures rise and contracts as temperatures fall. If you measure the expansion from one extreme to the other, you'll find that a typical siding panel expands/contracts at a rate of approximately 3/4 inch for every 12-foot vinyl panel.

For that reason, expert installers will always hang siding in such a manner that allows for just the right amount of "looseness" or "play" to accommodate movement of the siding during thermal expansion. It is crucial that vinyl siding be cut, lapped and attached with fasteners at just the right depth and with the proper spacing and layout to insure the installation will look its best regardless of the outside temperature.