Door jamb question

[Spencer Hochstetler]

I'm replacing old doors in my house, jambs included. Taking my old jambs off today, I noticed 3 kerfs about 1/4" deep ripped lengthwise in all the jamb parts. I assume that they are there to relieve stress. Do they serve a real purpose? i.e. should I put some in my jambs before they get nailed to the jack studs tomorrow? I should add that instead of purchasing them, I milled my new jambs out of poplar, so they didn't come with any longitudinal kerfs in them...

[Paul Girouard]

Taking my old jambs off today, I noticed 3 kerfs about 1/4" deep ripped lengthwise in all the jamb parts.

I assume that they are there to relieve stress.

Yup.

Do they serve a real purpose?

Yes, they relieve stress :D / prevent cupping of the wood.

i.e. should I put some in my jambs before they get nailed to the jack studs tomorrow?

It's good idea , with Poplar you might get away without them , if it's KD stock and hasn't been stored in a damp place.

I should add that instead of purchasing them, I milled my new jambs out of poplar, so they didn't come with any longitudinal kerfs in them...



Good luck happy hanging!

[Spencer Hochstetler]

Thanks Paul. I'm wondering if stress relief is for those who don't use HVAC year-round. Cupping seems like it would result from large humidity swings as in the days before air conditioning. I'm not challenging you, but I do wonder if this kind of thing is historical "baggage".

[Peter Quinn]

I worked in a door shop for a few years making custom passage doors. We sent the majority out with pre hung and never kerfed the backs of the jambs. We never had any call backs due to cupping nor requests from contractors to kerf or put relief cuts in the jambs. I don't recall seeing many jambs that have been kerfed lately, and none of the jambs I've worked on in my 110 year old house have been kerfed, we have no HVAC and no cupping problems. I think your safe with out it.

It might be a good technique for a bathroom door, though I doubt its necessary there either. Certainly not standard pratice any more. It might have been an old carpenter's way of dealing with jamb material that was already cupping prior to installation.

I think a more valuable idea would be to prime all 6 faces of each jamb piece before installation, or seal them with shellac for clear grade. Another good idea is to orient your jamb material so that the heartwood side of the board faces the door edge and the sapwood side faces the jacks. That way if the wood does cup it will cup away from the door's swing and not interfere with its motion. Might be too late for this if you've already built your jambs, but its still a good idea to back prime them and seal the end grain. Cheap insurance.

Good Luck.

[Paul Girouard]

I'm not challenging you, but I do wonder if this kind of thing is historical "baggage".



The post swings here are odd , one guy wants to do "all he can" to do it right.

The next guy wants to know if he can build authentic Chippendale or Greene & Greene Mission style furniture out of underlayment.:rolleyes:

Yes, it is a traditionally done thing, most doors jambs today don't have kerfs but they do have larger lowered areas , or raised areas, depends on how you look at it.

All I'll say is I generally do kerf my stock before I assemble my jambs , have I gone without kerfs , yes.

I did add that with good Poplar a very stable wood it may not be necessary , BUT if they cup and you have to pull 3 or 4 jambs and replace them how will that be?

If your jambs are assembled I wouldn't bother , but if they are not , I'd do it.

Agreement is not always possible , YMMV , Use no hooks , Void where prohibited by law.

[Spencer Hochstetler]

The post swings here are odd , one guy wants to do "all he can" to do it right.

The next guy wants to know if he can build authentic Chippendale or Greene & Greene Mission style furniture out of underlayment.

So which category do I fall in?? I'm pragmatic about things like this. If it's necessary to prevent the worst, I'll do it. If it's busy work, I'll not. That is unless the busy work makes the job look more beautiful when it's completed. Of course, it's no longer busy work then, eh?

I decided to mostly leave them alone. I did put relief cuts in a few pieces that had a little twist in them that was present when I milled them. I'll let you know in 20 years if I had a problem.

[Peter Quinn]

. I'll let you know in 20 years if I had a problem.[/COLOR][/SIZE][/FONT]

Uh, it won't take that long. You should know what direction things are going to go by next spring!:D:D

I wouldn't expect to see much cupping on well acclimated KD poplar that is 4 1/2" wide (standard modern jambs?) or so and 3/4" thick. Its just not that much of a problem, especially if the new jamb is being attached to dry old studs.

If you are really concerned ditch the poplar, and use QSWO for your jamb material! Or better yet attach poplar veneer to some LVL's and use those for jamb stock!

[Paul Girouard]

So which category do I fall in??

Your at this point , IMO , trying to be fence sitter. You wanted someone like me to agree that it was a waste of time. Again IMO if you found some one like me with 30 years of construction / cabinet shop custom one off woodworking experience you'd find a whole bunch that would say kerf them and like me some would have not kerfed at times (if they where honest) because they where rushed , didn't bid it that way , or just plain forgot to before they assembled them are some variant of all of the above.

I'm pragmatic about things like this.

Humm maybe , I think you wanted agreement and didn't get it.

If it's necessary to prevent the worst, I'll do it. If it's busy work, I'll not.

Humm thats why you kerf them , prevention. Do you consider easing edges as busy work before you apply finish?

That is unless the busy work makes the job look more beautiful when it's completed. Of course, it's no longer busy work then, eh?

Talking / typing yourself in a circle? If on a round about one must at some point select a direction if one is to get any where, eh!:D

I decided to mostly leave them alone. I did put relief cuts in a few pieces that had a little twist in them that was present when I milled them. I'll let you know in 20 years if I had a problem.



Thats was a good back up plan. Door jambs to cup , seldom do people call anyone back , maybe they don't notice , maybe they think it's been"to long" . I've pulled many jambs that where cupped , and most people in most houses have doors that do not operate properly , generally it's loose screws either on the door and or jamb side , a backset thats cranky (like me) because either the screws are loose , or it needs lubed , people just don't do that kind of easy maintenance thats why , IMO , the guy who said no ones called us back , hasn't had call backs , some or all of the above.

Generally forums have to basic types those that ask after the fact and just want some one to agree they did "the right thing". Or those that are seeking more knowledge so they "can do it " the right and or most right way.

Kerfing jamb stock is a quality job , it prevents or lessens the risk of cupping.

Period, you have decided , I hope all goes well for you. As before happy hanging!

YMMV < Use no hooks > Viod where prohibitted etc etc .

[Spencer Hochstetler]

[To your bolded and interleaved replies and below:]

Generally forums have to basic types those that ask after the fact and just want some one to agree they did "the right thing". Or those that are seeking more knowledge so they "can do it " the right and or most right way.

A bit judgemental I see, or forum jaded, or both. Actually, you are incorrect in suggesting/assuming/interpreting/accusing/whatever that I was trolling for agreement; I was simply trolling for people's experiences and knowledge. Afterwhich, I triangulated my decision, went out to the shop, and executed said decision. Between posting on this fine forum, one other, and a private email to a woodworker I trust, your feedback was but one consideration. I do thank you, however, it did inspire me to at least relieve some boards that had some stress in them already. Good day and try not to be such a librarian in your categorization of forum members in the future, it's annoying.

[Spencer Hochstetler]

Uh, it won't take that long. You should know what direction things are going to go by next spring!

That's good. That way this forum will have better odds of existing and I won't forget to post up!

[Paul Girouard]

A bit judgemental I see, or forum jaded, or both. Actually, you are incorrect in suggesting/assuming/interpreting/accusing/whatever that I was trolling for agreement


Good day and try not to be such a librarian in your categorization of forum members in the future, it's annoying.



Ah Spencer you sort of asked me what I thought , here's your post ,


[quote=Spencer Hochstetler;869390]

So which category do I fall in?? I'm pragmatic about things like this.

[/quote


Was that a rhetorical question? You did offer your own assessment so maybe it was :confused:

Was it my attempt at a clear answer that "set you off" so to speak?

You asked , I answered, the bold type made it clear , IMO , that those where my words , you figured that out so it was clear.


And you did asked about the kerfs in your org. post so maybe you didn't want any answer there either:confused:

Yet another mystery of the forum world. :o

Good day to you as well Sir. Good luck with those doors eh.

Sorry to have taken the time to annoy you by answering your questions :confused:

[Spencer Hochstetler]

Paul-

I don't like leaving a thread with annoyances lingering, so...

I began a discussion about the identity and merits of relief cuts and somehow it got to fora psycho-babble. Like I said, I appreciate your carpentry advice and took action how I saw fit after considering all of the information I collected as well as what my experiences told me. That's all. What I don't appreciate is presumptive folks telling me what I came looking for both in the face-to-face world as well as the electronic forum world. It is as simple as that and no "internet mystery" here. I don't understand, nor will I further try, why and how it became a psychology discussion. Let's just stick to wood - it serves us all for the better, don't you think?

-Spencer