Having purchased a 10-year old home with a pool, surrounded by a screen
enclosure, I find myself in need of some expert advice on how to
install new screening! While I've replaced window screens in the past
using ROUND spline, I've never used FLAT spline ... as a matter of
fact, I'd never even seen it before. There must be a reason that the
original installers used it, because it seems that all of the screen
enclosures here in Florida utilize that type.

As best I can measure it, the aluminum channel (into which the screen
and spline fit) is 5/32" wide, and the old FLAT spline measures
approximately 1/4" wide by 1/16" thick. (I looked up "flat spline" on
the web, and find that a standard size is 15/64" ... which is probably
what I have.)

My problem is ... how the heck do you get the spline to stay in the
channel? It stands to reason that it must be installed "width-wise" ...
15/64" spline forced into a 10/64" channel ... but every time I try
rolling the spline into the channel, it ends up twisting "side-ways"
.... or the spline tool slips off the spline and ends up damaging the
screening!

HELP! The must be a secret to installing this type of spline!

Or should I just give up and leave the installation to professionals
.... or replace the flat spline with round spline?