How to Install Insulated Vinyl Siding in 9 Steps

p>As the inventors of insulated vinyl siding, we frequently field questions from contractors and homeowners interested in the details of how to install insulated vinyl siding. Luckily, if you know how to install traditional hollow vinyl siding, you can install insulated vinyl siding.

The majority of the installation steps below are applicable to both vinyl siding and insulated vinyl siding, with a few differences that account for the additional thickness of the installation with the latter.

Tools You Need

  • Hammer
  • Square
  • Chalkline
  • Level
  • Tape Measure
  • Safety Glasses
  • Utility Knife
  • Table or radial-arm saw

    • Using a saw can help speed up cutting insulated vinyl siding panels and soffit. You must use a fine-tooth plywood blade installed in the reverse direction to appropriately cut the panels.
      Take care to saw slowly in extremely cold weather to prevent chipping.
      A fine-tooth hand saw can be used as an alternative.

  • Tin Snips

    • Good quality snips or compound aviation-type snips will speed the cutting and shaping of the vinyl.

  • Optional Tools to Make the Job Easier

    • Snap Lock Punch – Used to punch lugs in the cut edges of siding to be used for the finishing course at the top of a wall, or underneath a window.

    • Nail Hole Slot Punch – Occasionally it may be necessary to elongate a nail hem slot to hit a stud and allow for expansion and contraction.

    • Zip Lock (Unlocking) Tool – Remove or replace a siding panel by inserting the curved end of the tool under the end of the panel and hook onto the back lip of the buttlock. To disengage the lock, pull down and slide the tool along the length of the panel. Use the same procedure to relock the panel. (would be a good place for a tip of the week video)

The method of installation for insulated vinyl siding is similar for new construction and remodeling. Where there are differences, we have called them out below.

Selecting a Fastener

When installing insulated vinyl siding, use a galvanized, stainless steel, or aluminum nail – something that won’t rust.

Roofing nails with a ⅜” diameter head work well with vinyl siding. The Vinyl Siding Institute recommends using a nail that will penetrate at least 1-¼” into the nailable surface.

With hollow vinyl siding, a 1-½” nail can be used.

Insulated vinyl siding requires at least a 2” nail to accommodate the additional thickness of the insulation. When in doubt, always use a slightly longer nail.

Check your specific insulated vinyl siding manufacturer’s instructions when determining the length required for your particular product.

Terms to Know

There are many terms related to insulated vinyl siding that are important to know during installation. Refer to VSI’s detailed installation guide for a complete list of important terms. Below are just a few:

  • Drip Cap / Head Flashing – accessory installed with vertical siding to ensure that water drips away from panels.

  • Face – part of the siding that is showing once the panel has been installed.

  • Face Nailing – fastening directly onto the face of the siding panel, instead of using a nail hem slot. This practice is generally not used in vinyl siding installation except under special circumstances.

  • Flashing – A thin, flat material positioned under/behind j-channels, corner posts, windows, etc. to keep draining water from penetrating the home.

  • Fascia – trim covering the ends of the roof rafters.

  • Lap – to overlap the ends of two siding panels or accessories to allow for expansion and contraction.

  • Miter – to make a diagonal cut, beveled to a specific angle (usually 45 degrees).

  • Nail Hem – section of siding or accessory where nail slots are located.

  • Weep Holes – openings cut into siding or accessories to allow for water runoff.

9 Steps to Install Insulated Vinyl Siding

Below are 10 steps to install insulated vinyl siding. For a detailed guide, we encourage you to download the complete Vinyl Siding Installation Manual from the Vinyl Siding Institute. Click here to download>

#1: Remove Old Siding (If Necessary)

Depending on your particular project, you may or may not need to remove the old siding before insulated vinyl siding (IVS) is installed.

Traditionally, siding products such as vinyl siding, aluminum, and steel need to be removed. IVS can typically be installed over wood siding as long as it is free from damage and doesn’t create major projections from the wall.

#2: Correct Any Damage to the Wall

Insulated vinyl siding should be installed over a sheathing such as plywood or oriented strand board (OSB) that provides a smooth, flat surface. IVS should never be installed directly to studs without sheathing.

If you find any damage from moisture, pests, impact, or other sources after you have removed the old siding, it will need to be corrected before new siding is installed.

It is typically impossible to correct damage to a wall after siding has been installed, so take advantage of this opportunity to correct any issues beforehand.

Cut out the damaged sheathing and replace with new pieces, secured to the studs per the manufacturer’s instructions.

#3: Add a Weather Resistive Barrier & Flashing

If there is any loose caulk around windows or other openings, scrape it off and re-caulk to protect from moisture penetration.

It is a best practice to install a weather resistive barrier (WRB) such as house wrap to stop the intrusion of bulk water, although not every condition will call for it. Check your local building code requirements for your geographic area.

Code-compliant flashing around all windows, doors, and other openings should be integrated with the water-resistive barrier.

Flashing can also be applied to corners and at the intersection of walls and roofing. Many WRB manufacturers have tapes that can be paired with their house wraps to easily flash these openings.

#4: Install Accessories

Begin with the starter strip, which must be level in order for the siding to be installed perfectly level. Snap a level chalk line at the base of the wall all the way around the house.

Using the chalk line as a guide, install the top edge of the starter strip along the line, securing a nail every 10”. Be sure to leave a space for all corner posts and j-channels. Keep ¼” space between all starter strips to allow for expansion and contraction.

Make sure to use the appropriate starter strip to accommodate the additional thickness of the insulation.

An insulating starter adapter should also be used to appropriate start the first course of siding, provide complete insulation and protection at the base of the wall, where siding is most exposed to sources of impact damage. Check out the video below on using an insulated starter adapter.

Next are the outside and inside corner posts. Place the corner post into position, allowing a ¼” gap between the top of the post and the eave or soffit. Attach with a nail at the top of the highest slot on the post – the post will hang from this nail. The post should extend ¾” below the starter strip. Place all other nails in the center of the slot to allow for expansion and contraction.

When using insulating corner post inserts, it is helpful to cap the bottom of the post to hold the insulation in place. Check out our video detailing this quick trick>

#5: Trim Windows, Doors, and Other Openings

One of the trickier parts of insulated vinyl siding installation is installing j-channel or your preferred trim around all windows, doors, and other openings. Be sure to use the available wider j-channel trim to accommodate the added thickness of the insulation. If you aren’t sure which j-channel is required for your job, check out our video guide to selecting j-channel here>

Once you have selected your j-channel, you must appropriately cut and notch it to fit around all openings The top piece will need to be notched and bent to be provide flashing over the side j-channels. The bottom end of side j-channels will also need to be notched and bent into the bottom j-channel. Our video details how to cut j-channel to appropriately fit around all openings. Watch it here >

In some cases, you may have to build out the window before installing the trim if the insulated vinyl siding is thicker than the window jamb. This can be done in many ways, but a popular method is to surround the window in wood 2x4s, cap it with aluminum coil, then install the j-channel up against it. Watch the video below for full instructions on how to build out a window.

J-Channel must also be installed over roof lines. Keep the j-channel a minimum of ½” from the roofing material. Extend the j-channel past the edge of the roof to ensure proper runoff. If it is necessary to use more than one piece, overlap the j-channel, with the upper piece going over the lower piece to allow for proper drainage.

When installing j-channel under gables, let one of the sections butt into the peak with the other section overlapping. A miter cut can be used here for a better appearance. If more than one piece of j-channel is required, be sure to overlap the channels by ¾”.

Special accessories such as mounting blocks are available for other projections such as water spigots and lights.

#6: Install Insulated Vinyl Siding Panels

The first course of insulated vinyl siding should be placed in the starter strip and securely locked along the entire length of the siding panel before fastening. Nails must be long enough to penetrate into the nailable sheathing a total of 1-¼”. Check out this video on selecting the proper fastener for your job>

Nails should be placed in the middle of nailing slots to allow for expansion and contraction. For this same reason, do not drive the head of the nail tightly against the slot, but rather leave approximately 1/32”, or the thickness of a dime.

When overlapping insulated vinyl siding panels, no gap is needed. Simply butt each piece of foam together.

Once the first course is securely attached, continue up the wall by locking subsequent panels into the previous piece, then nailing to the wall. For best appearance and moisture management, stagger the laps, so no two courses are aligned vertically.

It’s a good idea to check every fifth or sixth course for horizontal alignment with a level. Also, check siding alignment with adjoining walls.

Always overlap joints away from entrances or the greatest point of traffic. This will reduce the appearance of the seams and provide the best overall appearance.

When using vertical panels instead of traditional horizontal panels, installation of horizontal furring strips may be required. You will want to install j-channel at the top and bottom of the wall using a chalk line to ensure level. To create a balanced appearance with vertical siding, make sure the first and last pieces on the wall will be the same dimension, similar to installing flooring.

#7: Finishing at Tops of Walls and Gables

Any soffit accessories that will be used on the eaves must be installed before the final course of insulated vinyl siding can go up.

To install around gable ends, make a pattern that duplicates the slope of the gable by holding a short piece of siding against the j-channel at the slope Mark the slope with a pencil on the short piece of siding. Cut along the pencil line as a pattern, which you can use to cut the actual insulated vinyl siding panels to be installed.

If it is necessary to fasten the last panel at the gable peak, use a 1-¼” to 1-½” trim nail. This should be one of the few times a nail should be used on the face of vinyl siding.

The last piece of siding at the top of the wall may need to be cut horizontally. Typically insulated vinyl siding can be thick enough to secure tightly into the j-channel, but utility trim can be used inside the larger j-channel for a tighter fit if necessary.

#8: Soffit Installation if Applicable

Soffit is used to enclose the underside of an eave. If you are replacing the soffit on a remodel, or installing on a new home, begin by installing receiving channels, such as soffit receiver, j-channel, or f-channel.

There are many configurations for soffit and receivers; you will want to determine which method is right for your particular application. We recommend checking out pages 33-37 of the Vinyl Siding Institute’s installation guide for specifics for your job.

#9: Install Shutters and Other Accents

When installing shutters or other accents, pre-drill holes through the shutters for attachment screws, then hold the shutter up to the desired location and mark it on the siding. Use a drill to make expansion holes in the siding where the attachment screws will be located, a minimum of ¼” larger than the diameter of the screw being used. Do not fasten the shutter such that it is tight against the siding, otherwise, the expansion of the siding will be restricted.

Final Thoughts

If you are familiar with installation of traditional hollow vinyl siding, there are only a few added steps for installing insulated vinyl siding. Be sure to use all the recommended accessories to accommodate the additional thickness of the insulation, and take care when trimming out windows and doors.

Full more detailed instructions, refer to the Vinyl Siding Institute’s installation manual here>

You can also use our Preferred Contractor locator to find a qualified, experienced installer of insulated vinyl siding in your area.


Sarah Carey :