A very simple solution (I didn't say cheap...but it is affordable) is to
measure your opening and subtract 1/8 inch from the narrowest width...I
would measure at the floor across the width and about 22-24 inches up
across the width.
 
We have found that 22-24 inches is high enough AND you can easily step over
it without falling on your face.
 
Materials needed:
 
(1) Piece of 1/8 or 1/4 inch sheet lexan (or any polycarbonate) cut to
your dimensions (a standard 32" interior doorway runs about 35-40 bucks).
If you are in big city...check out TAP Plastics...if you live in a rural
area...look under PLASTICS in your phone book.  DO NOT buy sheeting made
out of Acrylic Plastic..it will shatter after it ages a bit.
 
(2) pieces of 1/2 or 3/4 inch quarter round pine/fir moulding...found at
most hardware/lumber stores...Home Depot has it as does Eagle or any of the
big discount stores.  Cut to 1 inch above your polycarbonate sheet height.
 
(8) finishing nails long enough to penetrate your sheet rock walls and bite
into the wood framing underneath.  If your walls are wood..they just need
to be long enough to sink home into it (this does not apply to plywood
walls as found in many mobile homes...you will need solid wood behind).
Note: Most applications will find you going through 1/2-5/8 inch sheetrock
into the studs around the door framing so a 2-2 1/2 incher will do.
 
Finally...enough paint (you did save some from the last time you painted?)
or stain or finish to match your walls and/or doorframes.
 
Install the quarter round, spacing it far enough out to account for the
thickness of the polycarbonate plus a skosh (1/16-1/8 inch)...and afix
with 4 of the finish nails per side.
 
You now have a sliding channel that will hold the polycarbonate sheet in
place...you merely slide it in from the top.
 
If you have have ferts that are jumping jacks and can clear 22-24 inch
heights...you then need to install a piece of 3/4-1 inch plastic pipe
(schedule 40 works well) along the top edge of the polycarbonate sheet.
The hardest part is to slit the pipe lengthways...I use a small dado
blade with just enough width to be a tad smaller than the thickness of
the plastic sheet...that way you can stretch it a bit over the sheet so
that it holds itself on by friction.  A side benefit of this is that it
acts as a handle to pick the sheeting up by.  No fuzzy that I have ever
seen can get their grubby little paws over that pipe.!!!  A bonus is that
it give cats a visual fix so that they CAN jump over it without looking
like a complete dufus.  You do have cats, don't you???
 
If you need a swinging gate instead of a drop in...the polycarbonate sheet
can be drilled and fixed with hinges and a latch...AND it will pull the
screws out of the wall before the sheet shatters!!!
 
To some of you mechanically challenged folks out there this whole deal may
sound a bit overwhelming but it is a very easy project given a few simple
hand tools...and besides, you just wanted to go over to your neighbors and
use that new Craftsman table saw...
 
good luck!!
 
putorius
[Posted in FML issue 3030]