- The first course (row of panels) should be placed in the starter strip and securely locked along the entire length of the siding panel. Make sure the panel is securely locked before fastening.
- Fasten the panels in the center of the nailing slots (See Getting Started for more information for specific information on fastening and fasteners). Be sure that nail length is sufficient to penetrate framing or framing plus nailable sheathing a total of 1 1/4” (32mm). If the sheathing is a material that won’t hold a nail (e.g., foam plastic sheathing), the nail must penetrate 1 1/4” (32mm) into the framing regardless of the thickness of the sheathing.
- Allowance should be made for expansion and contraction by leaving a 1/4” (6.4mm) gap between the siding and all corner posts and channels. Increase to 3/8” (9.5mm) when installing in temperatures below 40° F (4.4° C). If the panels are 20 feet (6.1 meters) or longer, refer to the manufacturer’s instructions for how to increase the gap.
- Do not drive the head of the fastener tightly against the nail slot. Leave approximately 1/32” (0.8mm) between the fastener head and the vinyl siding (about the thickness of a dime).
- Do not force the panels up or down when fastening. Panel locks should be fully engaged; however, the panels should not be under vertical tension or compression when they are fastened.
- Since vinyl siding moves as the temperature changes, make certain that the panels can move freely in a side-to-side direction once fastened.
- Check every fifth or sixth course for horizontal alignment (Fig. 37). Also check siding alignment with adjoining walls.
- When panels overlap, make sure they overlap by one-half the length of the notch at the end of the panel, or approximately 1” (25.4mm) (Fig. 38).
- When overlapping insulated siding, no gap is needed between the foam at the ends of the panels. Be sure to butt each piece of foam together (Fig. 39), unless installing in cold weather (then consult the manufacturer’s instructions).
- Stagger the siding end laps so that no two courses (rows of panels) are aligned vertically, unless separated by at least three courses.
- Always overlap joints away from entrances and/or away from the point of greatest traffic. This will improve the overall appearance of the installation (Fig. 37).
- Avoid using panels shorter than 24” (610mm).
Fitting Siding Around Fixtures
Use a commercially available split or hinged trim ring (Fig. 40) to fit siding to a penetration such as a faucet or railing attachment, following the manufacturer’s installation instructions. If a commercial trim ring is not available for the application, refer to Fig. 41, which illustrates how to fit the siding to the penetration. In addition, the following tips are suggested:
- Install siding so that you have the factory end laps intersect at the fixture.
- Cut an opening 1/4” (6.4mm) bigger than the fixture or the trim ring.
- When cutting, match the shape and contour of the obstruction.
- For insulated siding, due to the thickness of the insulation, it may be necessary to build out the fixture or window and door trim to achieve the desired appearance.
Fitting Under Windows
To mark the section to be cut, perform the following:
- Hold the panel under the window and mark the width of the window opening on the panel. Add approximately 1/4” (6.4mm) to both sides to allow for expansion and contraction of the siding. These marks represent the vertical cuts (Fig. 42).
- Lock a small piece of scrap siding into the lower panel next to the window. This will be used as a template for the horizontal cuts. Mark it 1/4” (6.4mm) below the sill height.
- Transfer the horizontal measurement to the panel, which will be installed under the window. Measurement may not be the same on both sides of the window.
- Cut the panel with tin snips and a utility knife.
The cut panel is now ready for installation under the window. Perform the following:
- Using a snap lock punch, punch the vinyl siding along the cut edge every 6” (152mm) so the raised lug is on the outside face.
- Install utility trim (or double utility trim) under the window, as a receiver for the cut siding. Utility trim is used any time the top lock has been removed from the siding. Furring may be needed to maintain the face of the panel at the desired angle.
- Install the siding panel, making sure the lugs (from the snap lock punch) lock into the utility trim (Fig. 43).
Sidewall Flashing at Roof Lines
- Run the siding until the last full course under the roof area.
- Cut a diverter from aluminum trim sheet, making sure it sits on the nail hem of the last full course (Fig. 44). Make sure the diverter is placed inside the receiving pocket of the vertical J-channel and is tucked behind the nail hem of the J-channel following the roofline for best drainage.
- If a water-resistive barrier is present, a cut should be made in that barrier to allow the diverter to slip behind the roof step flashing and the J-channels. That cut will need to be sealed with tape (approved by the housewrap manufacturer) once the diverter is installed.
- As an alternative to the diverter, create a “kickout” from metal flashing, as shown in Fig. 45.
Finishing at the Top of Walls
Before the final course of siding is installed on the wall, any soffit accessories that will be used on the eaves must be installed. See the Soffit Installation section.
To install around gable ends, make a pattern that duplicates the slope of the gable (Fig. 46):
- Lock a short piece of siding into the gable starter course (i.e., the last course before the gable starts).
- Hold a second piece of siding against the J-channel at the slope of the gable. Mark the slope with a pencil on the short piece of siding.
- Remove the short piece and cut along the pencil line as a pattern for the gable angle cuts. Repeat the procedure on the opposite side of the gable. Check the angle template every few courses.
- It may be necessary to fasten the last panel at the gable peak with a trim nail. Use a 1 1/4” to 1 1/2” (32mm to 38mm) nail. This is one of the few times a nail should be placed in the face of the vinyl siding (Fig. 47).
The last course of siding may be cut to fit the eaves opening (Fig. 48).
- Measure from the soffit to the base of the upper lock on the previous course. Subtract 1/4’’ (6.4mm). Mark this dimension on the panel to be cut, measuring from the bottom edge of the panel. It is a good idea to check the dimension in several locations along the length of the wall.
- Using a snap lock punch, punch the vinyl siding along the cut edge every 6” (152mm), so the raised lug is on the outside face.
- Push the siding into the utility trim (or double utility trim) that has been nailed in place along the top of the wall. Furring may be needed to maintain the face of the panel at the desired angle. The raised lugs will catch and hold the siding firmly in place.
Optional Eave and Gable Treatment
Use a two-piece cover/receiver along the rake and eave (Fig. 49). Install the receiver flush with the top of the wall. Punch nail slots along the top edge of the panel every 16” (406mm). Use those nail slots to attach the panel to the wall. Snap the cover into place over the nails.
Transition from Horizontal to Vertical
- Finish the last course of horizontal siding with the J-channel and finish trim or double finish trim. Install head flashing and a J-channel.
- The top piece of J-channel must have minimum 3/16” (4.8mm) diameter weep holes drilled no more than 24” (610mm) apart to allow for water runoff, and the starter strip (J-channel) should not rest on head flashing because it will block weep holes. Leave a gap as shown (Fig. 50).
Transition from Brick to Vinyl Siding
- Caulk where the sheathing meets the brick sill. A head flashing (or drip cap) should be field formed and installed, then caulked where it meets the brick sill (Fig. 51).
- If horizontal siding is used, a J-channel or starter strip must be used. If starter strip is used, it is necessary to provide at least 3/8” (9.5mm) clearance for proper engagement of the siding.
- Use J-channel to receive vertical siding. Drill minimum 3/16” (4.8mm) diameter weep holes in the bottom of the J-channel no more than 24” (610mm) apart. Leave a gap between the J-channel and the flashing.