Replies

1. 
   Mongo | May 10, 2002 05:40am | #1

   I wouldn't recommend it. The edges/corners are susceptible to fracturing when getting dinged, and unless you use the right screws, MDF has a hard time holding hinge screws.

   I sometimes use it for captured (flat or raised) panels in doors, with poplar for the stiles and rails.

   If you go with MDF, you may end up having to tweak them repeatedly over the years, and you may even have to replace a few. Then where is the savings?

   I'd take a pass on MDF stiles and rails.

2. 
   rattail | May 10, 2002 05:58am | #2

   MDF is being used successfully for door jambs, trim, s4s and sheet goods. Until a year and a half ago I owned a Door and Trim company supplying homebuilders in central Indiana. We were rather skeptical about MDF when it was first introduced in our area. I think the purist or traditionalist in us caused us to consider MDF to be quite inferior to real wood.

   If you can set the purist in yourself aside, I think you'll find MDF to be quite good in a lot of applications.

   Some of it's drawbacks are: Heavy. Generates a lot of fine dust when milled. Is not strong enough to carry heavy loads. Need to use air nailers and more nails than normal. Special attention should be paid to the primer you use, as not all are sufficient. Screws should be a parallel core, instead of a tapered wood screw, and you should pre-drill screw holes.

   Some of it's benefits are: It's cost efficient. Consistently good surface to paint. NO knots, checks, cupping or twists. Good Luck.

1. 
   PhillGiles | May 10, 2002 07:56am | #3

   But getting it, and keeping it, plumb, straight, and square takes some work. Backing the hinge-side frame with ply helps if you have the space in the rough-in..

   Phill Giles

   The Unionville Woodwright

   Unionville, Ontario

1. 
   rattail | May 10, 2002 05:17pm | #4

   Phill-

   Don't you find that any installation is going to take some work to "get it right", no matter what the material. It's no easy task to set these doors correctly, and it seems to get tougher as framing lumber quality declines and rough openings seem to get more wracked and out of square.

   I was always under the impression that individual shims at the hinge locations were preferable to solid shimming as it allows you to tweak your installation more easily. For strength, we had 2 1/4" screws to run thru hinges into studs.

   For my own use on painted millwork, I prefer poplar. Solid poplar jambs, or other hardwoods, are simply priced too high for what many prospective homebuyers will pay,unfortunately. In the competitively priced group, MDF competes with finger-jointed radiata, iliata, and ponderosa pine and particle board jambs with paper or wood veneers. My impression is that MDF is more economical with more predictably good results.

   Best wishes. Pete

1. 
   PhillGiles | May 10, 2002 06:12pm | #5

   I'm not sure what it is you're really trying to say here Pete. MDF is far more plastic than natural wood and we liked the results of bonding a layer of plywood to the back of the hinge side of the frame to stiffen it up - you still need shims to mate it to the rough-in.

   Without the backer, the propensity for torsional skew inherent with MDF means, at least for me, a lot more time and work to get it square when compared to "wood". This is about the only place where I think MDF comes in second: it is an ideal material for base, casings, crown, etc.

   .

   Phill Giles

   The Unionville Woodwright

   Unionville, Ontario

1. 
   rattail | May 10, 2002 08:14pm | #6

   Phil-

   I think that laminating plywood to the jambs is a terrific idea. Thanks for the tip. My company supplied pre-hungs to builders and to my knowledge that extra step of stiffening the hinge jamb is not commonly used in this area. I was under the misunderstanding you were using a solid shim of some type. Once again, thanks for the tip.

   Pete

2. 
   PhillGiles | May 11, 2002 09:40am | #9

   Ah, that's what you meant. I first tried it doing 6' "french" doors (i.e. 2 x 36" doors) in a house with steel studded interior walls, and was going nuts. The door units were made by reworking 2 single pre-hungs (two hinge jam sides and the top was one of the "lock" sides cut to length and dadoed). The GC and the owner just accepted that it would take time to fit. The next time I did some work for that GC, guess what, every door jam had a ply stiffener on it..

   Phill Giles

   The Unionville Woodwright

   Unionville, Ontario

3. 
   rattail | May 11, 2002 08:21pm | #10

   Phil-

   Wow, that's a lot of work to go thru to come up with a 6/0 "french" door. There must have been some time constraints or other reasons not to have a prehanger build the specific unit that was required. Compared to all that re-working the single units, adding plywood to the backs of jambs was no big deal.

   I was kind of suprised that you mentioned steel studs in a residence. Is that commonplace in your locale? In central Indiana it's pretty much isolated to commercial applications. Virtually all residential here is wood studded and I assumed that would be the same in Canada, especially with your (assumed on my part) low lumber costs. Is steel studding commonplace? If so, what factors favor it?

   Pete

4. 
   PhillGiles | May 11, 2002 09:35pm | #11

   We see a lot of steel studs in commercial, not a lot in residencial yet, but becoming popular in basement finishing. I'm semi-retired, so I don't see enough sites to say definitively what's happening, but many custom houses seem to be wood for exterior/major weight-beariung walls and steel for partition walls lately. This particular house had a number of screw-ups in it, and one was the fact they roughed-in the steel to final rough-in dimensions and didn't leave any space for a wooden nailer for the jams or casings. Even if they had spotted it before drywalling, we could have put nailers into the perimeter (I hesitate to call them jack studs in this case) studs. For reasons that I don't really understand, I've noticed that a lot of these custom or in-fill houses put a lot of emphasis on the cost of the materials with little regard for how much they cost to install, or the skills required. You also see weird stuff, like $50,000 all-marble bathrooms with particle-board doors.

   Oh, I've done these pre-hung reworks a couple of time now, the single pre-hung doors are generally stock items and fairly inexpensive, especially when they are bought in bulk and/or on sale; the double doors cost three times what a single costs and may take weeks to special order (and you have to make a special trip to pick it up, or pay to have it delivered, ... and what if it's wrong or broken, ... and what if it's late), and they're still time-consuming to fiddle.

   Best joke on someone was when they had some wood/glass french doors down-stairs and figured out that I was making jams from scratch for them in about the same time as reworking their prehungs.

   .

   Phill Giles

   The Unionville Woodwright

   Unionville, Ontario

   Edited 5/11/2002 2:41:50 PM ET by Phill Giles

   Edited 5/11/2002 2:46:36 PM ET by Phill Giles

   Edited 5/11/2002 2:48:18 PM ET by Phill Giles

5. 
   rattail | May 12, 2002 02:47am | #12

   That sounds like the house from hell!!! Is the GC still in business? Hope so, but I imagine that was an expensive problem to correct. In a case like that, is that the Framer's fault or the GC's fault? I suppose a case could be made either way. It's a shame though, all that disruption due, most likely, to shaving costs on studs and plate material.

   Your right about weird expenditures. What gets me is when there is a $75,000 home theatre in the basement and the customer balks at spending maybe $35 more per door unit for solid core doors instead of hollow cores. I mean really, we're supplying basically the same product in $400,000 homes as we do in apartments!!! In the final analysis, my industry has not marketed the product to the end user as well as the kitchen/bath cabinet and fixture or the consumer electronics industries. They have created a desire for their products in the end user. We haven't, and our goods have become commodities and the primary focus has become finding lesser cost substitutes. Not a good situation, but as I say it's my industries own fault.(rant's over)

   Pete

3. 
   archyII | May 11, 2002 02:39am | #7

   Thanks for all the advice.  I think I will stick to solid wood for now.  I have used MDF for trim and loved it since it was flat and straight.  I will have to spend some time at the lumber yard selecting clean straight stock for the door jambs (they still let me go through the piles and pick my pieces)(I stopped using one yard where they just loaded your truck and said that you could not pick through the pile)).

1. 
   JeffBuck | May 11, 2002 07:15am | #8

   Your local yard should have premade jamb stock for you. Back kerfs already routed. If you have odd thickness walls and have to make your own....remember to cut the kerfs along the back to help eliminate cupping.....and a slight angle from the face to the wall......like 3 to 5 degrees.....will help the trim set tighter. Jeff                             "That's like hypnotizing chickens........."