Screen spline, nothing can be easy!

Old 12-16-16, 06:43 AM
jjrbus's Avatar
Thread Starter
Join Date: May 2010
Location: US
Posts: 325
Received 2 Likes on 2 Posts
Screen spline, nothing can be easy!

I am repainting the structural aluminum and replacing the screen in my Lanai, (rich peoples word for screen room) probably 20+ years old.

I am not a contractor or professional just another idiot with a hammer, not wealthy and a lifetime DIYer.

I have had issues with the screens, in some spots they come loose and the spline must be reinstalled in some area's. Spline is too small you think, me too. But I had planned on painting and re-screening so did not investigate.

As I am removing screen and spline I notice a difference, some of the spline is not round but flat. This is in the areas where I have no issues with the spline coming loose.

So off to the computer, there it is "flat spline" Hmmm, I look at my groves and most of them match the flat spline description. But there was an addition to the Lanai and of course that is different.

So the smiling guy in the how to install flat spline video says it only comes in one size so no issue there. :NO NO NO:

I look around to buy some and of course it comes in 2 sizes that I see. 0.3125 or 5/16" and 0.344 so I have to measure mine. Poopies it measures 0.294, give or take a couple hundredths.

I can't find anything smaller that 0.3125 online. So did my 0.294 use to be 0.3125 and shrink? Is there a smaller spline somewhere, can I just stretch the new spline as I install it. Whats a poor old guy to do?

Plus I want to add some vinyl windows instead of screen in a couple places, but I will leave that for another thread.
Old 12-16-16, 06:52 AM
XSleeper's Avatar
Group Moderator
Join Date: Dec 2004
Location: USA
Posts: 29,434
Received 1,578 Likes on 1,414 Posts
Yes it probably has shrunk a couple hundreths.
Old 12-16-16, 06:59 AM
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 28,341
Received 1,628 Likes on 1,461 Posts
I would try the 5/16" spline. Fresh spline is more pliable and will be easier to re-install. Since your tracks are old they may not be smooth which can make installing the spline a bit more difficult. I dampen a rag with WD-40 and wipe the spline down before installing. The bit of lubrication makes it slip into the slot much easier especially if the track is a bit dirty or corroded.

As for the shape of your old spline it may be just because it's taken the shape of the slot. It probably was round when it was new.
Old 12-17-16, 07:18 AM
johnam's Avatar
Join Date: Jan 2000
Location: USA
Posts: 2,044
Received 12 Likes on 11 Posts
When I was in business, I must have screened thousands of screens. I hated the square spline and never reused any shape old dried out spline. Spline was made of a rubber or vinyl in the early days and later made of foam. The foam was easier to use, especially in your situation since you will be screening the screens in place and not on a work bench. Look for it locally so you can buy a piece to try for size. Here is a link:SWISCO Foam Screen Spline :

Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: