Replies

1. 
   charlie_sullivan | Jan 01, 2021 03:28pm | #1

   The model that Wire Cutter ranks their top pick, the X-It, claims to have no limit on wall thickness.

   https://www.nytimes.com/wirecutter/reviews/best-fire-escape-ladder/

   Werner has one that installs permenantly in a recessed box under the window, and attaches there, so that should also work, althouth the details of mounting to an ICF wall might be something you'd have to figure out and it's certainly something you'd want to be sure to get right.

   https://www.wernerco.com/us/products/specialty-products/fire-escape-ladders/ESCSeries

   Some, like the ISOP https://isopllc.com/usa/, have carabiners at the top. You could provide your own mount points for those, permanently anchored in the walls. Although you'd be on your own on how to hide them in an aesthetically neutral way without impeding fast access.

1. 
   Trevor_Lambert | Jan 01, 2021 04:06pm | #2

   The x-it also relies on carabiners for the no wall thickness limit. The optional hooks clearly have a fixed size, implying some definite limit.

1. 
   charlie_sullivan | Jan 01, 2021 04:39pm | #3

   Trevor, I think you might be misunderstanding how their hooks are used. The hooks are too small to embrace the wall + trim for even a regular wall. The hooks go over the interior trim (the "stool") with the pointy end pointing into the wall, not down, and the flat part lays on top of the window sill. the straps then go as far as they need to out from there before turning downward.

   They do offer a permanent attachment point option with carabiners, but they say no limit on thickness with either arrangement.

   https://www.x-itproducts.com/questions/?v=7516fd43adaa

1. 
   Trevor_Lambert | Jan 01, 2021 06:15pm | #4

   Yes, I was looking at a picture that turned out to be different brand.