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Need help with bi-fold doors

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https://sigforum.com/eve/forums/a/tpc/f/320601935/m/1870097715

October 19, 2025, 01:10 PM
400m
Need help with bi-fold doors
My furnace room had bi-fold doors that broke. I bought replacements after work yesterday. Yesterday morning the old doors went to the curb for trash.

The new doors measure @ 79-1/4” with track and hardware. The finished opening measures 82-1/4”. I know they have plenty of room around them but the doors themselves are 78-3/4”. That leaves 3-3/4” of difference. The top of the door isn’t adjustable, so the bottom would have to be raised to make up the difference. I can raise the bottom bracket off the floor but it is on a slab so it won’t be easy. I don’t have the old doors to compare. Having to raise the bottom bracket 3” off the floor seems like way too much.

I suppose I could drop the height of the opening a few inches by putting a header strip in there and painting it. Is there something I’m not thinking through?
October 19, 2025, 01:31 PM
gpbst3
Do the doors have a metal threaded adjustment screw post? It should have a cone type head which would give you an inch or so adjustment.

https://www.homedepot.com/p/Pr...Set-N-7269/100554477

Its the left side piece in the link


October 19, 2025, 01:35 PM
HRK
They are a PIA, hired out the last set at my daughters, lowered my BP quite a bit!

For all things install look to the toob!

Lots of videos on udoitoob...


October 19, 2025, 01:39 PM
400m
Yes they do. The top of the door will be, 11/16” (height of the track) plus a bit for the pivot pin, below the finished surface. That means the bottom of the door will be roughly 3” off the floor.
October 19, 2025, 02:51 PM
Genorogers
Sounds to me that you need to rebuild the opening to fit the doors that you purchased.
October 19, 2025, 03:23 PM
phil in indy
it seems to me that I have built up the opening at the top with 1 x 4 or 6 to make up for the difference in mine
October 19, 2025, 05:11 PM
petr
Can you mount these brackets on the opening at the distance from the floor you need?

https://www.homedepot.com/p/Pr...ket-N-6992/100120299
October 19, 2025, 05:48 PM
sig operator
See this often. Old standard openings are different heights than current standard openings and sometimes the width is different.
Best to remove casing and reframe opening to work properly.
October 19, 2025, 05:56 PM
400m
I don’t think it would hold without support from below. Even the old doors were elevated with a strip of wood but it was only about 3/4” tall. My bottom anchors are just like the ones you linked to. Maybe I’ll nail up a strip at the top and paint it and then mount a hardwood plinth to the floor with concrete anchors. That should split the distance and create a little balance.
October 19, 2025, 06:00 PM
400m
Sig operator, it’s all drywalled just like a closet would be. I’m not going to tear all that apart and re-drywall the opening for a few furnace doors. I’m gonna cheat and add a painted wood strip. Big Grin
October 19, 2025, 06:03 PM
400m
Heck, I wanted stained doors like my baseboard but no way am I going to finish assembled louvered doors. I’d make my own before I’d sand all of that.
October 19, 2025, 06:25 PM
trapper189
You got three choices if you want it to look good: make the opening shorter or make the doors longer, get the right size doors.

I’m fairly sure the bottom of the doors have a threaded height adjuster, so making the doors longer would mean glueing strip to the top and drilling new holes for the hardware.

Adding a strip to the top of the door frame is an option you mentioned.

If you don’t care about a gap at the bottom, then tapconing a 3” spacer into the concrete on each side and installing the brackets for the bottom of the doors to the spacers would be an option.

If the correct height doors are available, I’d take the ones you bought back and get the right ones.
October 19, 2025, 08:12 PM
400m
Option 2 is the winner!
October 19, 2025, 09:08 PM
wrightd
I hate those damn things, but they sure are nice when they work smoothly. My experience is they don't last forever, but the ones I've had were not of any quality to brag about.




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Wile E. Coyote School of DIY Disaster
October 20, 2025, 06:58 AM
mark60
You can get 82" bifold doors or lower the header to meet what you have.