What Is the Nail Hem?
Look at an uninstalled vinyl siding panel.
Along the top is a strip containing elongated slots.
That is the:
Nail hem.
The fasteners pass through these slots to secure the siding to the wall.
Why Are the Holes Long Instead of Round?
Vinyl expands and contracts with temperature.
The slots give the panel room to move horizontally.
Why Should Fasteners Be Centred?
If the nail is placed at one end of the slot, the siding has less room to move.
Correct installation keeps the panel secured without locking it rigidly in place.
Why Shouldn’t the Nail Be Tight?
Vinyl siding should hang from the fasteners.
A nail driven tightly against the panel can restrict movement and contribute to:
- Buckling
- Distortion
- Wavy panels
This Is Why Installation Matters
A premium siding panel can still perform poorly when fastening is wrong.
The Small Slots at the Top of the Panel Are Part of the Siding’s Movement System.
Envirotech Exteriors installs vinyl siding with the expansion and fastening details the material requires.