Expansion and Contraction
It’s normal for vinyl building products to expand and contract
with temperature changes. To ensure a successful siding
installation, you must allow for this movement during
application.
Use the following guidelines to determine the space required
for expansion and contraction between siding and trim:
1/4" at both ends of the panel when the temperature is above
40° F at the time of application.
3/8" at both ends of the panel when the temperature is 40° F
or below at the time of application.
In a horizontal siding installation, a vinyl panel tends to expand
equally in both directions.
In a vertical siding installation, on the other hand, most of the
expansion is downward. So instead of allowing equal space
for expansion at both ends of a vertical panel, leave more
space at the lower end: 1/3 of the total expansion is allowed
at the top of a panel, and 2/3 of the total expansion is allowed
at the bottom.
For example, if the temperature is below 40° F, total expansion
equals 3/4" (3/8" + 3/8"), so you allow 1/4" at top and 1/2" at
the bottom of a vertical panel.
Installing Accessories
Snapping a chalk line
To ensure proper installation, you must establish a straight
reference line to guide the positioning of the starter strip and
the first course of siding.
If the house is reasonably level, find the lowest point of the old
siding (or sheathing if working on new construction). Partially
drive a nail at one corner, starter height minus 1/4" above the
lowest corner. Attach chalk line. Go to other corner and pull
the chalk line taut. Stretch the chalk line from this nail to the
opposite corner of the house. Make sure the line is level, using
a line level or 4' (minimum) level. Snap chalk line and repeat
the procedure around the entire house.
26
Wolverine Fit and Finish Installation Guide
1/4" to 3/8"
1/3 total expansion
2/3 total expansion
top most nail
at the top of
the top most
full nail slot
center
remaining
nails in the
slot
