Mastering Roof Inspections: Accessing the Roof, Part 4

by Kenton Shepard and Nick Gromicko, CMI®



The purpose of the series “Mastering Roof Inspections” is to teach home inspectors, as well as insurance and roofing professionals, how to recognize proper and improper conditions while inspecting steep-slope, residential roofs. This series covers roof framing, roofing materials, the attic, and the conditions that affect the roofing materials and components, including wind and hail. 


LADDERS, Part 2 

Ladder Length

Extension ladders are a good choice when a ladder has to be leaned against a roof. They’re typically available in lengths from 16 feet to 40 feet, with choices in between in 4-foot increments. Ladder lengths are a personal choice.

Because extension ladders come in two parts which overlap, the length given is not the length of the ladder when it’s fully extended. For example, a 16-foot extension ladder has two 8-foot sections, but will only be 13 feet long when it’s fully extended.

Extension Ladder Material

Extension ladders are available in steel, aluminum and fiberglass.

  • Fiberglass ladders are strong and don’t conduct electricity, but if stored outdoors, they will weather, especially in humid climates. A coat of lacquer or paste wax will help extend their service life.
  • Steel ladders are strong, but they conduct electricity, so you’re at higher risk from shock or electrocution. If, while you’re standing on a steel ladder, you lose control and it comes into contact with overhead electrical wires, the result could be dangerous.  Also, steel will corrode over time.
  • Aluminum ladders are lightweight, but they’re generally not as strong and flex more than steel and fiberglass ladders. Aluminum ladders also conduct electricity.
  • Wooden extension ladders are no longer common. They can be strong ladders if they’ve been well-maintained over the years. Look for cracks and loose rungs. Wooden ladders should have a finish coat applied to help prevent weather damage.

Standing an Extension Ladder

Trying to stand a tall extension ladder can be a challenge if you’re doing it alone. Here’s the proper way to stand an extension ladder:

  1. Choose a level area on which the base will rest, once the ladder is stood.
  1. Check overhead to make sure that the ladder will have plenty of clearance from any overhead wires.
  1. While it’s still unextended, lay the ladder on the ground with the base against the bottom of the wall and the top pointing away from the wall.

  1. Starting at the top of the ladder, lift the end over your head and walk under the ladder to the wall, moving your hands from rung to rung as you go.

When the ladder is vertical and the top is touching the roof, move the base of the ladder back a distance equal to about one-fourth of the distance from the ground to the point of support (usually, the gutter or fascia).

  1. Ladders at too steep an angle are at increased risk of going over backwards as you climb. Ladders at too shallow an angle may overload the side rails, and the base of the ladder is more likely to slide as you climb. Once the ladder is stood, it can be extended as high as necessary.

The top of the ladder should extend at least 3 feet above the edge of the roof.

  1. The ladder should be straight and secure. If the ladder leans to one side, place a firm material beneath the foot on the low side. If you dig holes in the lawn to adjust your ladder, the homeowner will not be running out the door to compliment you on your inventiveness. Don’t dig holes in the lawn.
  1. If the ladder might slip, such as on a smooth concrete surface, brace the base of the ladder or use a non-skid mat. If you can’t make it safe, don’t climb the ladder.
  1. Never set up or use a ladder in high wind, especially a lightweight-type. Wait until the air is calm enough to ensure safety.
  1. Never set up a ladder in front of a door unless the door is safely locked or a guard is posted. You can hang a notice on the inside of the door. Do whatever is necessary to prevent someone from walking out the door and knocking loose the base of the ladder. It’s especially bad news if this happens while you’re on the ladder.

  1. Tie off the ladder so that it can’t blow over (leaving you stranded on the roof), and to make it safer to mount and dismount from the roof. Conditions at the roof edge will be different on different homes; some homes have gutters, some have just fascia, so you’ll need to be inventive. Carry a variety of devices with you, such as clamps and bungee cords. Don’t depend on the tie-off connection to prevent the ladder from moving when you step onto and off of the roof. Don’t nail anything to the roof.

To take the ladder down, just reverse the process you used to stand it. Remember that you’ll be walking backwards, so check for obstacles in your path.


Extension ladders have shoes that pivot so that the bottom of the shoe stays in contact with the surface, improving the ladder's stability on hard surfaces, such as concrete. Shoes often have rubber soles to better grip hard surfaces, and also to protect finishes on decks and balcony planking.

When pivoted all the way back, shoes lock into place with the sharp end down (called the spur), helping to prevent the base of the ladder from slipping.

Ladder Levelers
Adjustable leg extensions are available for setting the ladder up on surfaces that are not level.


Learn how to master a roof inspection from beginning to end by reading the entire InterNACHI series: Mastering Roof Inspections.

 Take InterNACHI’s free, online 
Roofing Inspection Course
Mastering Roof Inspections
Roofing Underlayment Types
Inspecting Underlayment on Roofs
Fall-Arrest Systems
Roofing (consumer-targeted)
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