How Can I Tell If My Vinyl Siding Has Been Installed Correctly?

The key to successful vinyl siding installation is in the planning.  Proper installation is the best way to ensure your vinyl siding looks great and will stay that way for a lifetime. The method of applying vinyl siding and soffit is essentially the same for new construction and renovation projects.  In all installations, care should be taken to properly prepare your home’s exterior structure and it is always recommended that installers review local building codes before starting a project of this nature.

To tell if your siding has been installed properly, you should look for two main things:

1. There should be no buckling or warping in your vinyl siding.

2. Is there room to move?

Grab the end of the vinyl siding where it overlaps another piece of cladding and tug gently. It should move side to side a bit, not a lot, but there should be some room for expansion and contraction.

Even home inspectors conducting a visual inspection will use these two indicators, as vinyl siding is ‘blind nailed’ by design, meaning you are not supposed to see how it is nailed, nor see the types of fasteners nor the substrate.

For properly installed and professional looking vinyl siding, you need two key components:

1. Quality vinyl siding

PVC (polyvinyl chloride) is the vinyl that's used in vinyl siding.  It includes a number of additives that help resist fading, protect it against ultraviolet rays and provide dozens of color choices. The color goes all the way through the material, so it can't flake off.

Vinyl siding standards are covered by the American Society of Testing and Materials (ASTM) Standard 3679  Any vinyl siding you buy should have this designation on product fact sheets and packaging.

2. An experienced installer

A contractor's expertise and experience are crucial to a great looking vinyl siding job.  Because vinyl expands and contracts so much, even the most expensive siding will buckle and warp if not installed correctly. Experienced contractors take a number of steps to keep these errors from happening.

Ensuring Proper Installation

The two key components of properly installed quality vinyl siding are, keep it straight & level and allow room for expansion and contraction.

1. Keep It Straight and Level

Keep in mind, siding is only as straight and stable as what lies under it. Below are some problems you can avoid before you start installation:

• In a re-siding project, the addition of strapping or removal of uneven original siding may be necessary.
• In new construction, avoid the use of green lumber as the underlayment.  Green lumber may warp over time if the wood hasn’t been properly cured.
• When installing a siding panel, push up lightly along the bottom until the lock is fully engaged with the piece below it and do so for the full length of the panel.
• Throughout the installation project, check the horizontal alignment of the panels every few rows to make sure the siding is hanging straight and level on the wall. Also, check for panel alignment around corner posts and above doors and windows.

2. Allow for Expansion and Contraction

Vinyl siding contracts and expands as the outside temperature changes. To avoid structural or aesthetic problems associated with this characteristic, take the following steps:

• Apply nails or other fasteners in the center of the nailing slot and make sure the fastener penetrates a minimum of 3/4" (19mm) into a framing stud or furring. Make sure installed panels and accessories move freely from side to side.
• Do not drive the head of the nail tightly against the siding nailing hem. Allow approximately 1/32" (0.8mm) clearance (about the thickness of a dime) between the fastener head and the siding panel. Drive nails straight.
• Leave a minimum of ¼" (6.4mm) clearance at all openings and stops. When installing in temperatures below 40 degrees F, increase minimum clearance to 3/8" (9.5mm).
• Do not face nail or staple through the siding except for one nail needed to finish at the top of a gable.

Before you start your home’s vinyl siding installation project, make sure you check references of any contractor you are considering. If possible, use a VSI Certified Installer. This is especially important for warranty considerations. Siding warranties will cover the siding itself, but not problems caused by shoddy installation. It is a good idea to request written estimates from your contractor and visit past jobs they have completed and any current project they are doing to give your contractor a thorough assessment.

Using these tips your vinyl siding should be properly installed and look great for years to come.