[Neil kell]

On that type of surface there was always gonna be a risk. Normal rule of thumb ofcourse is the usual 1:4 or 75 degree angle, I'd definitely go steeper on that surface as it would be like an ice rink with the early morning dew. Sand bags would be your only man there. Place a sand bag on the bottom rung of the ladder to mimic it being footed and then with the other safety precautions, 3 palmer grip, don't carry anything up, don't over extend etc, you should be fine. Youv'e been led into a false sense of complacency with your ladder mat. As you said earlier, you like to work traditional, stay traditional, dump the ladder matt and stay safe.

Neil.

If you weight 75Kg and you nearly fall over because it's so slippery, a sandbag will do nothing at all. You need spikes.

http://www.ladderm8.co.uk/

Not just a few spikes on the ladders feet, but a whole mat of them. 

I hear ya with the spikes, but tilting the ladder to a steeper incline i.e 80 degrees and using a sand bag is more practical. I doesn't need to be a sand bag, just something with a bit of weight in the customers garden, a large stone or a bin or something. Your only going up for a few moments, You wouldn't stay up there for long. Sand bags can be more reliable than people for footing the ladder. People can wander off.

[clearlyclean]

Get a long arm pole and never fall off a ladder again from window cleaning center I used one and still do on occasional jobs before i went WFP stay safe and keep both feet on the ground

[Jackal]

taking about spikes i had a wake up call today on a terrace house,not done it before,ground was flat and slabs laid down,got to the top just reaching for my washer and the ladder slipped about half a foot to a foot crapped it, but the spikes dug in when they reached the gap where the next slab was,it was a stupid mistake by me not the spikes as i put it on more of an angle as a flood lamp was in the way where i wanted ladder go,it got me thinking tho what would of happened if it was normal ladder feet,i dont think they could have stopped at all

[traps7]

I'm wfp now but when I was trad I never had problems in 16 years. A couple of lucky escapes in the beginning, but you learn from them. It's all common sense. It depends on a combination of surface type, surface wetness, algae, ladder angle, both stiles evenly resting on the wall, slope of the ground, weight, and condition of your ladder rubbers/stoppers.

I probably wouldn't have entertained putting a ladder on those quarry tiles. Spikes are a joke on hard surfaces. It'll wreck the surface. And I don't see the point of them on grass as you can dig in without them. Ladders are perfectly safe used properly.