Any reason to BUY extension jambs? I am putting Anderson 400 series windows in my house, and the walls are an odd thickness – structural panels that are OSB both sides and a layer of drywall on the inside. Total thickness of 7-1/8″. I can only imagine (and dread) the co$t of buying extension jambs for all these windows. If I get some decent pine stock, can it be easily milled and attached to a “standard” frame?
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Replies
You can definetely make your own. Will the jambs be stained or painted?
You can use biscuits, pocket holes, or just shim and nail to the trimmer.
Jon Blakemore
RappahannockINC.com Fredericksburg, VA
I can't think why biscuiots. Thewse are Andersen windows so the best way to make the extensions is a moderate dado on the pine like the premade ones have. That snaps right together and aligns straight.
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That's a good point about the andersens. I've seen some biscuits but not many, probably because it's really not necessary.
Jon Blakemore RappahannockINC.com Fredericksburg, VA
not really a reason to buy them ...
but lotsa good reasons to order the windows to fit the known thickness in the first place.
Jeff
Buck Construction
Artistry In Carpentry
Pittsburgh Pa
If you`ve got too much variation in wall thickness, I definetly would recomend against purchasing the extension jambs premade. I also recomend poplar over pine. Better pricing unless you`re planning on doing alot of puttying and stain kill primer with knotty pine.
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Jon - "I can only imagine (and dread) the co$t of buying extension jambs for all these windows. If I get some decent pine stock, can it be easily milled and attached to a "standard" frame?"
What's your TIME worth? It takes time to rip & mill your own extension jambs. Making your own could very well be penny wise and pound foolish. Contrary to what some of the others here are suggesting and saying professionally speaking we know we can't make them cheaper than we can buy them. While they are a pretty simple operation to make any manufacturer can easily produce and provide them cheaper and with less chance of defects than we can set up and make them. Whenever possible we order the extension jambs. (We try to build and fabricate only the stuff we can't outsource somewhere else).On one large job we did a while back where the window fabricator didn't provide extension jambs we outsource them to another shop since we didn't have the excess capacity to do them without interrupting some other process we had going at the time.
If this is your own home your talking about and your looking to save the money since it your own home we them maybe it might be worthwhile to to make you own but then again you'll still have to make the subjective decision as to what your times worth and also consider how much Quality you can get out of making your own. What does "decent pine stock" mean?
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It's my own home. Time is worth whatever I want it to be. I have the tools to make it, and I have a few hundred board feet of clear KD quartersawn white pine. Two thiings I don't know are: how difficult they are to make (I have read the FHB article on installing vinyl-clad windows and it SEEMS simple enough) and how much they typically cost. I haven't priced out the window package yet. If it's $20 a window, then I'm looking at an extra $500 or so for the package. That's PROBABLY worth it, and will save me that stock for something else.
No paint, BTW - everything will be stained/tinted and clear finishes.
Maybe this will sound goofy to some of the pros, but I've made my own (HO GC DIY)several times, some out of selectively ripped and end-cut #2 pine, and the wider ones out of red-oak veneer 3/4" plywood. Pre-finished with shellac sealer and 2 coats of polyurethane. When you case out the plywood, just leave the reveal so you can only see the veneer label and slightly less than the first lamination.
Looks fine.
If you are using Andersen series 400 windows, and if you are within Brosco's distribution area (US NE), then the tongued extension jamb stock is available in lineals through your dealer (a lumberyard that buys from Brosco.)
Here is a clip from Brosco's site. Apparently there are different profiles depending on the product line and series.
View ImageGene Davis, Davis Housewrights, Inc., Lake Placid, NY
I priced out a custom depth extension jamb on a large window package just last week, and found the price to be about $20 per window, that for the extenders factory applied.
If each window, to do it yourself, requires two 8 or 10 foot lengths of knot-free straight clear pine stock at 1x4 size, plus your time to measure, cut, fit, and fasten, I cannot see how you can justify making these yourself.
Each time the subject gets raised here on Breaktime, there is a chorus of carpenters who sing the "make them yourself" tune. IMHO, these folks are those who are doing work where, a.) they aren't buying the materials, and b.) they get paid by the hour.
Gene Davis, Davis Housewrights, Inc., Lake Placid, NY
Personally I like to trim and apply the jamb extensions (manufacturer supplied) myself. There's always too many variables in window set. Being cut to length and already rabbited is definitely a time saver. Final fit in the field.Remodeling Contractor just outside the Glass City.
Quittin' Time
On a recent trim job I had to make all the ext jambs, and yes it was time consuming. Builder had me fasten jamb ext with trim head screws into windows, just offset the holes past the reveal for casing glued and screwed. It was to be all stain grade and he didn't want to see any fasteners in jambs. Why the windows were not shipped with jamb ext. have no idea, I was paid by the hour so it was his dime.
I just happened to take a couple of pictures of extension jambs I made for some Anderson windows. This home was trimmed in red oak, so, the jambs and sills are oak. Board sheathing was used, therefore, factory extensions would not fit. I've always found it easier to make my own, particularly if the framing wasn't nailed flush or wall thickness varies for some other reason. The Anderson factory extensions are rabbeted to fit into a groove in the window. I didn't use a rabbet on this job. I attach directly to the window so shrinkage isn't much of an issue at that junction. My process does require careful placement of the screws and a correct length. Screwing the windows shut or restricting the tilt feature isn't good. You may have to shim and face nail for extra wide extensions. For extensions wider than 3 1/2", I would recommend using a rabbet. Andersons aren't available for different thickness walls unless you want to pay and wait for custom.
Andersons are very uniform in size. You can cut all the pieces for 20 alike windows the same, and have them fit nicely. I like to assemble the extensions on the bench and pop the whole thing in place rather than do them piece by piece. I think it speeds up the process and keeps things square. You still have to scribe in the sill for each unit, if you use a sill, and want a tight fit.
I like to pre-finish the materials and paint the walls before trim installation, when possible. I measure all the windows and take the average for the width of the extensions. They sometimes vary 1/4" so I split the difference. Remodeling can be another story. The space between the framing and extension jambs gets insulated, of course. If the factory was able to supply the wide extensions, they would likely be finger jointed, not solid. They could be warped, too. I think you would be happier making your own.
I was just talking to my suppler RE: windows for my own house (new construction w/ 2x6 walls) & asked about extension jambs & he said that some people simply use a drywall return instead of extension jambs.
Has anyone here done that? Any thoughts?
Sheetrocked window openings are done all the time to lower the cost of the trim package. Can be done nicely with bull nosed corners but will never look as nice as a properly lined and cased window.
Just a note about anderson liners: They use veneers over finger jointed stock for stain grade wood. If you need to scribe them to unusual wall conditions they are not very forgiving.
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Edited 7/21/2005 3:50 pm ET by Adam Greisz
Edited 7/21/2005 3:50 pm ET by Adam Greisz