How to fill an area with a polyline or pattern

Hello All,

First post and novice AutoCAD LT 2009 user here, so please go easy! I've lurked for a while gratefully harvesting some handy hints, but this time after much searching I've realised I need to post my own plea for assistance.

I'm creating drawings which show areas with heating in the floor. I hope that someone can point me at a shortcut/tool/addon which can save me some laborious polyline work in getting those heating pipes into rooms!

I need to fill areas with lines at specific spacings, usually 200mm between lines. This can vary, but I'll keep it simple for now.

The patterns which I need to fill the areas with are shown below (spiral and serpentine). Not a great problem for a regular room shape, but a pain if the rooms are irregular shapes, particularly when I'm doing the spiral layout.

Being able to specify some additional criteria is also important, but for now I'm trying to keep my request to the bare minimum.

This seems like the sort of thing there is probably a tool or addon for, but I haven't been able to find anything yet. Any help will be very gratefully received! Its driving me a bit nuts thinking I can't find a solution for something seemingly simple.

It might be something that could be handled with a lisp routine but LT does not support the use of lisp. I think you need to upgrade to the full version of AutoCAD.