# Shim before jamb installation?



## vinny186 (May 7, 2016)

I was watching Hometime and they were installing heavy 8' doors. The installer tacked up the shims on both sides before installing the jamb. How does he know how much to overlap the shims without having the flat surface of the jamb to determine plumb? 

The guy was very experienced but i've never seen it done that way.


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## Snoonyb (May 7, 2016)

Were the shims, in pairs, opposing each other?


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## vinny186 (May 7, 2016)

Yes. 

Perhaps he shimmed again after installing the jamb but I didn't see it. however, if he did shim again, what was the point of shimming the first time without the jamb in place?


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## Snoonyb (May 7, 2016)

The practice is neither common or uncommon, just his method.

The logic is the fitting the jamb to a straightedge after the top and bottom have been set becomes just a matter of taping the shims to tighten the jamb against the straightedge, in stead of holding the straightedge while inserting opposing loose shims.

Any carpenters you know have three arms.


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## joecaption (May 8, 2016)

I've had to do it a lot in older homes because there so far off from being plumb.
I use a 6' level to get an idea how flat and to see if the top and bottom of the R/O are plumb.
I've seem some so far off I had to add a 1/2 thick piece of plywood before the door is set so I did not need a thick stack of shims.
If it's an old house your working on also check the floor to see how flat it is, it's not uncommon to have it so far off even in that a short span that the jamb leg will need to be cut or shimmed to get the door to set square.


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## rokosz (May 12, 2016)

I like the hometimer's method -- but if they're "tacked", with the intention of adjusting once the jamb is in place,  how do you tap the shims to adjust? you'dhave to remove the "tack"ing yes? meaning you gotta remember to leave access to the tack.   or am I missing something?


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## nealtw (May 12, 2016)

The shimming on the hinge side is to make that side plumb before you hang the door frame. People that have a 6 ft level do it that way.


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## Snoonyb (May 12, 2016)

rokosz said:


> I like the hometimer's method -- but if they're "tacked", with the intention of adjusting once the jamb is in place,  how do you tap the shims to adjust? you'dhave to remove the "tack"ing yes? meaning you gotta remember to leave access to the tack.   or am I missing something?



Tap the shim with a hammer, it splits and moves inward.

The action is the same for both sides.


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## jeffmattero76 (May 13, 2016)

nealtw said:


> The shimming on the hinge side is to make that side plumb before you hang the door frame. People that have a 6 ft level do it that way.


I agree with nealtw. Make the hinge side plumb before hanging the frame. I do this all the time. You must have a 6 foot level.


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## jeffmattero76 (May 13, 2016)

As nealtw stated, use a 6 foot level and plumb the hinge side BEFORE installing the door frame. Makes the job far easier.


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## Snoonyb (May 13, 2016)

Interesting!

How about squaring the jamb?


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## jeffmattero76 (May 13, 2016)

I do that first. Place a level across the floor of the opening to see if one leg of the jamb needs to be shortened. If so, cut the required amount off of the long leg of the jamb. Then plumb the hinge side and install the frame as described earlier. All that is left is to shim the latch side to give an even space between the door and the jamb on the latch side.


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## Snoonyb (May 13, 2016)

Squaring the jamb, is the process of using a carpenters square with the jamb captured in the short leg of the square and the long leg against the wall on either side of the the opening, because aggressive rookie shimming can result in the jamb leg being twisted over its length.


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## jeffmattero76 (May 14, 2016)

Sorry, I misunderstood your question. I do check  that and adjust the hinge side by adding shims to bring it square. Once that is done I check to make sure the head jamb is square to the hinge jamb. Then I close the door and shim the latch side to create an even space between the door and latch side jamb.

I am sure there are other ways  of hanging a door, but what I described is how I was taught years ago by an old  carpenter.


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## Snoonyb (May 14, 2016)

Yep, there is so much more to "hanging a door", then you'll find on an internet video, much less a logical explanation.


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