Doors – 12′ sliding door frame shimmed up against header and sagging at point where shimmed

doorsframeshim

I have a sliding door with glass panels on each side, spanning a width of 12 feet. The door has been sagging in the middle. It slides easily at the edge (when open), but drags near the center. I tore off the siding and flashing above the frame outside and found 2 1-inch wide shims between the header and the door frame right in the center of the door (shims lying on top of each other filling the approximate 1/4 inch gap)

It looks like the pinch in the slide is exactly at this point. To my eyes, it seems that the header is putting its weight on those shims, pushing down on the frame.

A few questions:

  1. Can I remove those shims? I cannot imagine that the 12' header was suppose to be supported by either the shims or the frame, so I think that I can do so safely.

  2. Those shims are pinched pretty good… how do I remove them? I could reach a saw blade in and just chip them out I suppose…

  3. Should I be worried about the sag? The house is 32 years old and with those shims any sag would be immediately felt by the door frame, so I can confirm the sag isn't that much since the door can still open and close.

Thanks very much for any help! This is outside my normal DIY home repairs and experience, so any advice would be appreciated!

Best Answer

Without a full mental picture, here are my initial suggestions...

Can I remove those shims?
Probably. Head jamb anchor points are sometimes needed to prevent horizontal (in-out) movement in the frame, but if you have mounting flanges or something else on the door to do that they aren't needed. Most doors I've installed have been done without head jamb shims for just this reason.

How do I remove them?
A reciprocating saw (Sawzall) will cut the nails or screws and leave a bit more space to remove them. A flatbar as a lever can also relieve pressure.

Should I be worried about the sag?
You haven't told us what the header is, nor how much sag you're seeing. Chances are it has sagged all it's going to sag, unless the header was drastically undersized. Do you see evidence of sag above the header? If that's substantial and growing you should get an expert on site.

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