You can get almost any depth you want, but this depends on the material you build your slide with. With mine, it was suggested to only go 18-22" on two that were about 13' long, and I could get up to 25" on my two that were 10' and 8', and using steel for the framework. But if I use aluminum, I could get closer to 30-36". But, I'm trying to figure out the engineering and cost difference first to see if it's worth the extra $$$ to go with aluminum tube.
Shoot them an email to
ecommerce@lci1.com and let them know your needs. They are great at getting back to you ASAP. I've been working with Gary Stillwell and he's been very helpful.