Monday, March 10, 2014

Garage Door Jamb Size



I'm replacing my old wooden garage doors with two Reliabilt (Amarr) Model 300 single layer 9'x7' doors purchased from Lowe's. The instructions say
The opening must be framed with 2 x 6 minimum wood jambs.
The jambs that the existing tracks are mounted to are 2x4s. Is it really necessary to replace them with 2x6s? I'd have to move some electrical cables, and one jamb would be blocked by an electrical box containing light switches, but I suppose I could notch around that. The instructions apply to doors from single to triple layer, and for up to 20'x8' doors.

As long as the current jamb is sufficiently nailed to the framing such that there is no movement of the jamb when operating the door, you should be alright to install as is.

I think you are speaking of returns and not jambs. The return can be 2x4, as long as the track hardware fits on it. The jamb is what is on the flat side of the entrance where the door slides up and down. Normally they are either 2x6 or 2x8 depending on type of wall construction. Since you are replacing doors, your jamb is probably already set in place and you're good to go.

Thanks Chandler.
Where the instructions use the term jambs they're referring to the surface to which the vertical tracks are attached. There's a diagram with them labeled 2 x 6 jamb, they refer to parts as jamb brackets and they talk about fastening them to the jamb. You can see this in an old version of the instructions here. And it's not just this company, apparently it's the industry. By Googling I found that DAMSA (the Door Access Systems Manufacturers Association International) has this technical data sheet talking about Wood Horizontal and Vertical Back Jamb Detail Guidelines which recommends a minimum size of 2x6.
I think you're suggesting that the 2x4s that the existing tracks are mounted to should be sufficient as long as the new hardware fits. Thanks, I'll probably reuse them and save myself some work.

I'm convinced whoever writes the instructions for garage door installs, has never actually put one in. If you follow the pictures exactly (looking at the screw hole profiles in the picture), the side vertical rails will be installed upside down and the mechanical lock mechanism will not marry up with the pre-cut slot that it is to fit in. Made this mistake once, and everytime I have put one in since, I note the diagram and it still has not been updated. So does not surprise that they are not calling a jamb a jamb.

If you have a torsion spring, make sure the top back jamb is a 2x6 that is 11 longer than the door itself. The side back jambs can usually be 2x4.

Thanks XSleeper. My doors use extension springs.






Tags: garage, door, jamb, size, existing tracks, existing tracks mounted, hardware fits, layer doors, that existing, that existing tracks, that existing tracks mounted, tracks mounted