Can I lean a ladder against tempered glass without damaging the window?

Question

We are building, and just now after the windows have been installed is that I realised they are really high up.

The window is made of tempered glass 8mm thick, 3.5 m wide, 2.5 m high and starts at 3.5 meters above the ground, so it is 6 m at its highest point.

I was thinking about putting a ladder against the window when I was going to clean it, but I'm not sure if tempered glass can withstand the pressure of ladder and someone climbing it for cleaning.

Answer 1

Even if the windows were super thick, it wouldn't be strong enough to handle the pressure exerted by a properly positioned ladder.

A ladder is supposed to be sloped 25%, like this:

With someone standing near the top of the ladder, that means roughly 20% of his weight is directed as lateral force, directly into the wall or window, conveyed by the points of the corners. That could easily be hundreds of PSI, enough to crack almost any glass. That force is temporarily multiplied as each step is taken with something like acceleration and deceleration (this is the basics of physics kinematics, F = ma).

Wrapping the corners of the ladder with something soft (like a thick towel) would greatly reduce the pressure by spreading its force over a much larger contact area. However, the same total force is still applied, and that could well exceed the loading limit of the glass or its frame.

Leaning against glass is a high risk, low benefit undertaking. If the window breaks and the ladder moves, will that make you fall off? Will sharp, heavy pieces of glass fall onto you or be blasted into your face and eyes? Will you fall onto a window shard still held vertical in the frame?

There are many solutions which are easy, painless, and relatively inexpensive:

• Lean the ladder beside the window
• Get a longer ladder which can rest on the wall above the window
• With climbing gear, belay yourself from above
• Rent scaffolding, a cherry picker, or a self-supporting ladder like an A-frame or orchard ladder.

Answer 2

Don't do it. Put the ladder above the window, then clean by putting your arms through the rungs.

Shouldn't the windows have a way to tilt them inward and clean from inside the house? Most every modern window I've seen has a way to do that.

You may want to get a ladder stabilizer:

Answer 3

Either use a A frame ladder or a squeegee on a pole. I personally wouldn't trust my health on the structural strength of glass.

Answer 4

Get a combo sponge / squeegee on an extendable pole. They work very well.

It is also possible to get these window washing soap bottles that have an integrated sprayer mechanism. You attach these to a garden hose for water. They easily can spray a nice and vigorous soapy stream or water at the windows over 20 feet (like 6 meters) high. Normally the surfactants that are in the cleaning soap allow the water to run off the window and leave it clear when you switch the sprayer to rinse mode.

I use these spray cleaners to clean 2nd floor windows and then if there are particularly difficult spots I'll work with the sponge on the pole. Then re-spray the window with the spray. The squeegee can come into play if there is stray water remaining.

Answer 5

I wouldn't do it, you're just asking for trouble especially with such a larger window that will likely flex with the pressure.

In any event, how would you clean the entire window if a ladder is leaning against them?

Answer 6

I know that this does not exactly answer you question, but here is an alternate option to your probable problem: I would get a water fed window cleaning pole squeegee.

pros:

• It seems to me that it is safer, since you stay on the ground.
• You wont need to go up and down the ladder.
• the chance that the window breaks and that you possibly hurt yourself AND need to buy a new window is way smaller.