Trimming Vinyl Window Extension Jambs & Casing - Fastest Method to Shim Extension Jambs

In this video we tackle vinyl window extension jambs. I show you what I think is the fastest method to shim window extension jambs, or as some call them, jamb liners. To case the windows I'm using my usual clamp and hipur assembly method. For shimming the rough openings I like 1-5/8" fine thread drywall screws. As you'll see in the video, this is a very fast and productive way to install window casing when extension jambs are required. Links to those products below.
Infinity PUR WW30 Polyurethane Hot Melt - geni.us/g5DEvGw (Amazon)
Infinity PUR-3000 Dual Temp Corded PUR Hot Melt Applicator - geni.us/s20i9r (Amazon)
WoodRiver Miter Max Corner Clamp - geni.us/oFw2e (Amazon)
#6 FINE Thread Drywall Screws with Phillips Drive #2 Bugle Head - geni.us/9xFUoH6 on Amazon (commissions earned)
(0:00) Using Drywall Screws to Shim Openings
(3:14) Cutting Extension Jambs
(3:45) Batch Cutting Window Casing
(4:52) Pre-assembling Window Casing Sets
(7:20) Assmebling Casing/Jamb Units
(8:11) Installing Window Casing/Jamb Units
My Favorite Tools - Insider Carpentry Amazon Site - www.amazon.com/shop/insider_c...
Support more content like this by becoming a PATREON SUPPORTER - / insider_carpentry
INSTAGRAM - insider_carpentry

[@anavrinhsub6081]

The more I learn the more I realize I know nothing. Thank you for sharing!

[@InsiderCarpentry]

That makes two of us. 👍

[@pwhsbuild]

Great tip and work! I don't do this for the bottom sill plate on windows. I cut blocks of various thicknesses and carry pre-cut buttstrip. I use this for shimming the bottom in 3-4 places. That way when a kid (or goofy adult) steps on the sill like they shouldn't, it is absolutely solid and doesn't move. The sides/top I will use this method.

[@treystills]

Thank you so much for educating! Very generous of you to share your time, talents, and energy. Thanks again

[@chadmarsh3118]

Great job! Finding someone who cares about the quality of their work is rare! 👍🇺🇸

[@tc9148]

Wow, such a great tip. You are Mr. Productivity with all the terrific preassembly tricks.

[@GRJCLyon]

That’s a true carpenter that has pride in his work. A dying breed. Well done, sir. 👍🏻

[@82hilljh]

This is just the approach I need for finishing of the windows in my garage. I have several windows I want to install the trim as a single unit, but could not figure out how to shim the unit. This video came at the 👌 time. Thanks!

[@zack8399]

and this is why i subscribed. Not only the tips and tricks, but how you explain and communicate is great. You and ScottBrown in NZ are my top yt carpenters to watch. You should do more tools reviews ;)

[@InsiderCarpentry]

Thanks man! Thanks for the feedback.

[@MrLegendL2118]

Yup agreed, and also Richard from Finish Carpentry TV, I don’t watch anyone else 🤓

[@izzymolina4041]

Would love to hear your background in finish carpentry. You have the knowledge and articulation of a legend.

[@georgetrujillo9618]

I've seen this done so many ways, this one is a first and the result is so clean and professional

[@jamartin1]

Wow! Very good way to shim with the drywall screws! Love it!! Thank you!!💜

[@rattown99]

Your level of detail is off the charts, great job!

[@dhammer5645]

This is always why I order jamb receiver track on all windows I will be trimming out. Good job Spencer👍

[@stevebengel1346]

Great job 👍 I " accidentally" discovered this method about 15 years ago when I went to trim a new house and realized after I started that the supplier didn't bring the shims, so I had to improvise

[@shigthehandyman]

You are truly a master at efficiency! Awesome work man!!

[@jefferyholland]

Gonna need to start taking notes of all of these nifty hacks. I have used the screw head hack on some other situations but never on jamb extensions. Another nugget from Insider Carpentry.

[@nickpersenaire4443]

I'm definitely going to try this method next week on the window job I'm on. I batch cut and picture framed all of my exterior casing it turned out great. Thanks for sharing the great content.

[@InsiderCarpentry]

Good luck!

[@Coop442s]

Great video, I’ve learned so much about finish carpentry from your videos. Keep up the great work!

[@productiontrimcarpenter]

Can not thank you enough for this tip. Started using the drywall screw shims 6 months ago, and today was shimming 20 windows with your method. Takes a minute to shim them, but the install more than makes up with the time saved, and piece of mind that goes with the time savings. You Rock Spencer! Thanks again for this excellent content.

[@InsiderCarpentry]

You bet brother!! Happy to help.

[@Warren3carpentry]

This is the method I like to use whenever possible. Great job!

[@BK-fy2xi]

This is a cool trick. Way more uniform then the piece by piece method I have done in the past.

[@datFUNKYb]

Used this method today. My goodness, so efficient. Thanks, my dude.

[@bryanblahut]

I live in southwestern Ontario (Canada), we call the jamb extensions as well. Great video

[@realworldcarpentryremodeli5868]

Hey Spencer. Great tip . Very simple and effective. Thanks for your insight.

[@InsiderCarpentry]

You bet!

[@bryanbryan7080]

so lucky to have that run of windows installed plumb, square and level across the total run. would be a 1% chance this would be the case on a remodel. nice work.

[@timothywalz9692]

Great video. Love the shim idea. Definitely going to use that method for sure. Thanks for the videos you post.

[@larrymagar8169]

Looks great . After we made our jamb extension we would use a foam gun to insulate between the extension and the ro then put the casing on. It fills the gap and makes them very secure also.

[@thadh4085]

I saw you check the bottoms to make sure they all lined up, and it looked good on the video. It's nice to see quality framing followed with a quality finish. True teamwork

[@InsiderCarpentry]

Yep. Whoever installed these windows had them dead but in plane and also consistent depth in the opening. Makes life so much easier.

[@thadh4085]

@@InsiderCarpentry I saw you're comment over on Finish Carpentry TV and was curious if you had any tips or ideas for running those long lengths solo.

[@anthonycaldi7056]

I dig the shim trick. Did not see that coming!

[@chrisswartzwelder8494]

Always super nice job.

[@gunnrboy]

Wow! Could have used this tip for some windows in my house. Awesome idea! Love your videos.

[@Whoisddepew]

I use that same method with the drywall screws when I do oversized cased openings works really good keeping everything straight without having to attempt to shim something that could be 8 to 10 inches and width.

[@sretaw275]

Wow great trick with the drywall screws as shims, I so stealing that idea, thanks for the trick and love the videos, please keep them coming. Also yes you can teach a old dog new tricks, I'm a retired carpenter.

[@KurtMGibbs]

Very clever method...I never thought of doing it that way.

[@MrBeard-ig5zc]

You are one smart mother lover..... Thanks for giving the love away..

[@InsiderCarpentry]

Anytime. 👊

[@kcbowls300]

Spencer is a GENIUS!!!!

[@glennsgarageshop]

Awesome job Spencer!!👍

[@BrutalRain]

My boss would never go for this. One of the sups suggested this method and he shot it down. We also line and case individually. I appreciate all your videos and I've tried integrating as many efficiencies that I can get away with. It's really helped. Thanks

[@enxunw1282]

What's the downside of this approach?

[@BrutalRain]

@@enxunw1282 Not the way it was done in 1972? 🤷‍♂️

[@Estwing22]

@@enxunw1282 if you pre-assemble all the windows and then get sent to another job, you might get criticism after the guy who takes over removes all the trim from the extension jambs and installs them separately so he can insulate between the extensions and the framing. My thought has always been that if the window unit is insulated to the framing, that r value is higher than that of the sash itself so why do you need insulation between the framing and extension when you have no insulation on the other side of the jamb (in front of the low r sash). Previous to spray foam, the fiberglass we stuffed those cavities with was imperfect and if there were a draft through the original insulation then the added jamb insulation helped keep you from having cold jambs but these days with spray foam is it really necessary?

[@jemalwright3414]

Nice!. I just installed 7 of the same windows in my house. I'll try the same method. Great Video and thanks for posting!

[@johnthopper]

I do the exact same thing by shimming with the screws. Your jig is a great idea was just eyeballing it in the past

[@ghshomeimprovements]

Fantastic job mate. Long ago Vermonter showed me screw trick and it’s wonderful.

[@texascraftsman7215]

Love it!! an old carpenter showed me that and I never looked back.

[@WowRixter]

Well done. So simple and effective

[@codyboyles309]

Super efficient as always, if I run into windows like those again ill definitely be trying your method. 99% of the vinyl windows here have a 3/4 jamb return on them, basically a dado around the outside so your jamb extension just slides right in, no need for shiming and eliminates any slight difference in depth

[@InsiderCarpentry]

That would be handy. 👊

[@Matt-kb7gv]

Looks like I got another method to show off great stuff love your channel

[@timmattison6553]

Another great video. Looks great

[@makermarc70]

I'm Canadian. I have called them jam extensions for 40 years. Keep up the great work!

[@joblowu]

wow! amazing work

[@ldoginak]

I have always assembled my casing then installed them with 18 gauge pins, adjusted the reveal to where I like it then put small blobs of can foam about every 12” around the window. Under the sill I put solid foam. Then install trim after foam has dried. Probably a bit slower but insured a very solid casing install and it never pulls from the vinyl window. *just have to be careful not put to much foam as to bow or bulge the casing!

[@jeffreyvazquez6344]

Amazing. Thanks for the tip and great work.

[@jasonmelo566]

The framing is mint at that house. Great job! I use that method for basement windows. But I'll improve it with your jig and drywall screws hack, TOP ideia.

[@bossHogOG]

Jason Melo proper framing and window alignment are key. Most of the tract housing I work on have windows out of level/alignment. Makes doing the trim a PITA!

[@2chipped]

Another excellent tutorial 👌.

[@fheaney1]

Fantastic idea

[@petera.watters4459]

I did 13 windows last summer, 1/2 were up about 9', and it was all roughed in horribly with gaps etc. I could have used this method on most of them though, wish I would have. Next Time!!! Thanks for the great tip!!!!

[@Nick0777]

Just wow ! I learned so much.. thanks

[@dickdoc3337]

Well done Lewis have a great weekend :)

[@davem3789]

Awesome method! I’m building a garage and my exterior walls are 2x8 and I had been wondering how to do jamb extensions for my mandoors. Thanks!!!

[@semperfi5861]

Good idea! We frame and trim out the entire house when ready. When we install the windows we angle all the sill plates 5° and cut the RO height 1/4" larger. We shim up the windows with 1/2" plywood/OSB (whatevers on hand). When putting together our jams and casing we just set them in the RO on the 1/2" shims. We then sight around the jam and window reveals as needed and then nail off the casing as needed. I work with an old timer (40+ year Carpenter) and this is how he's always done it. I showed him your video on coping and he laughed, lol. He's really quick its unreal. This old timer literally runs laps around 20 year olds, lol. 😊👍🇺🇸

[@InsiderCarpentry]

👊👊 There is a lot to be learned from the older generation. They did a lot with little for tooling. But times change and there are plenty of innovative tools to adapt with also. 👍

[@InsiderCarpentry]

Thanks for all the comments and channel support! Infinity PUR WW30 Polyurethane Hot Melt - amzn.to/3oHMku4 Infinity PUR-3000 Dual Temp Corded PUR Hot Melt Applicator - amzn.to/3kKo1th WoodRiver Miter Max Corner Clamp - amzn.to/37Zlqrx #6 FINE Thread Drywall Screws with Phillips Drive #2 Bugle Head - amzn.to/2GeD1Aq

[@gizmobently]

Nice job Spencer. Very nice and quick quality work. I also use screws for baseboard installation. I end up with drywall factory edge at very bottom and need to "screw" them out prior to baseboard install so it doesn't tilt in too much. Also use them in coped corners and just adjust the screw to fit the opposing cope cut. Dial in the fit with the screw head. Also keeps my joints nice and tight. As for those windows, I can understand that as a sub coming in to do this you can't be that hung up on sealing these windows up tight. I get that. But that looks like a 2 x 6 wall that the bank of windows are in overlooking that lake and if that is west or north facing, those jamb extensions are crying to be filled in with non expanding foam prior to sealing off with your wood. I know I would have done it if it were me but only if they paid me to do it. Forgot to add FYI. Anderson sells these extensions in a vinyl finish wood to match their window interior you are extending off from. Thst's a choice for GC of house, not yours. They do look very nice and are very durable around any moisture buildup on those windows which will sweat in the winter. Especially on the bottom.

[@johnnyvannoy8931]

I like the idea and think it would work great as long as the windows are set plumb and the jambs are straight . I just recently had to straighten the jambs on 24 double hung Windows where the installer placed the windows in the openings and nailed them in with bowed jambs and all . This really showed up at the trim stage .

[@stevenfoust3782]

Been shimmin it with a gage/jig. Your way is definitely faster and equally solid for what’s required.

[@gsh319]

You do some great work madman, very clean job. absolutely great method. Myself,.. Even if those units had not been laid in dead on level, set up and adjusting the inside units on end units set up to the seat screws would be easy. Great method, Thanks as always, sure to use it.

[@robertsmithUH60driver]

Thanks for the tip. Looks good.

[@BillTiemann]

Nice work. I'm not trimming out houses any longer but when I was doing trim work anything I could do to achieve speed, accuracy and consistency was foremost in my mind. Your drywall screw technique here is excellent. All I am doing now is custom cabinetry and built-in furniture pieces.

[@awdc13]

Badass

[@dwp2659]

wow great idea! well done

[@farmfitnesspham4913]

Nice work

[@petemiller519]

Super video!

[@angelarellano4819]

Awesome job

[@TheGrizz00]

As a window treatment installer, I really wish more trim carpenters did your quality of work. Makes me sick to find a NC house with 1/2-3/4” differences in a wood jamb. Well done!

[@JoDoDesigns2011]

Amazing great job 👍

[@timcorbett9629]

In our area, we staple a vinyl u-channel to the face of the window. I think you can get them in 5/8" or 3/4". Vinyl matches the window color. I pre-assemble the extension frame, scribe and trim for width if it's really uneven. The U supports the frame, and hides any gaps if there is movement later on. Nice clean finish when you're done.

[@gizmobently]

That u channel is a good idea as that joint will have to be caulked anyways. That would look better especially if you are using varnish grade finish trim, as a caulk joint does not work with that type of finish. I would ask the window manufacturer to furnish them since they have to be extended and if memory serves me correctly, Anderson windows does sell them as an accessory to their windows. At least they used to years ago. I had to do all mine but my difference was very small extension (vinyl coated wood extensions) to match window finish) and I could nail them on directly to window.

[@rmd35501]

Great tips. I never seen anyone use drywall screws in place of shims. Great job

[@martinphillips7221]

Between you and RRBuilder great content

[@InsiderCarpentry]

RR is a content machine.

[@fatcat-hc4pj]

Man I wish I would have seen this yesterday trimed out 6 windows today shims everywhere

[@diegocelaya8036]

Haha ain't it always thecase you figure something out then go on you tube and see what you could have done better

[@NickWhite630]

Ingenious!!

[@jimcaldwell4204]

Love using screws for shims.

[@kennelson5096]

I like to use plywood shims. 1/8, 1/4, 3/8 etc. Shim space from stud to window. Gives you a nailing area. Precut all, install as 1 unit. Goes fast. Gives you space to add expansion foam for insulation.

[@kiwdwks]

Awesome as always! Thanks again for sharing your techniques!

[@hampyonce]

They still make hand screwdrivers. You are carpentry wizard, though. I've been involved in homebuilding since the70's. I'm a second generation builder. And, great idea on the screw shims and jig. I'm showing this to my guy.

[@DavidMoncrief]

Mind blown. What an awesome method. You could level cabinets this way too- even if just to do it and install wood shims later. If you build your own cabinets you can level your base (ladder) this way. Why have I been using wood shims all this time?

[@shandorszentkuti6330]

I used to work with a carpenter a long time ago who showed me a similar technique for hanging doors. He’d hang the plumb bob and set a high, middle and low nail on the hinge side flush with the string and push the jamb up against them, then tack it in place with a couple finish nails, add the shims and finish nailing it off.

[@bradleyjohnson1177]

I understand its fast, but i still prefer to do jamb extension and casing separate so i can insulate the space between jamb and framing. Also, I put more screws on bottom because someone is bound to put a lot of weight on the window ledge. Love this channel.

[@InsiderCarpentry]

Nothing wrong with that man. 👊👊

[@als1023]

Up in Canada we insulate the gap, but the prebuilt jams I've used for a very long time. I prima and 1 coat my jam material before cutting, and then it's one coat of paint on the finish product after nail hole fill and corners. I've used a commercial hot glue gun for years, but never on trim ! That's a great idea, thanks ! Love the efficiency work flow ! I'm not sure what the reveal on the window plastic to liner is, I leave 1/8". Anyone know what Spencer leaves? Thank you to all the great subscribers to this channel, comments are excellent !

[@johnnyk123]

What do you use to insulate that space?

[@loumonte658]

Outstanding.

[@yepper1165]

For what its worth I have a method I like. I think I'm going to change my first step to incorporate your method though. I like to measure the windows to get what I want for the size if my jambs. I build my jambs. I shim (next time I'll use screws instead) the bottom of the opening. I set my assembled jamb in the opening, centering the bottom. I nail the bottom. Then I shim it in place like I would the latch side of a door, nailing it as I go. I use my vibrator tool to cut off my shims and its ready for casing. The thing I like about your method is you can assemble it with the casing on and install in as a unit. I may try that now that I've got the Pur gun recently. Was afraid to do that in the past because I was afraid I'd break the corner joints on the casing apart. I really like your videos and think it's great that you are free with your experience. There are a lot of generous people who post videos of how they do things. But you are skilled beyond most of them. You're ahead of me, that's for sure! I get good results but u ou do it even better most of the time and your efficiency takes the time factor down a long ways. Keep up the good work.

[@JS-ct5jn]

Life goals

[@darinb3524]

Very nice!!

[@garrettlund]

Another epic video! Can’t think of anyway to improve that besides adding your clone 🤣 anyways keep up great work. I’m spending time off Instagram and back to just following a few of these builds for better learning and less time wasted just looking at pics. Great job!!

[@InsiderCarpentry]

It does get to be a waste of time for sure.

[@ryanengland6054]

Id love to come work with you for a few months! Id learn so much

[@benchippy8039]

Great tip, I’m in the Uk so we plaster our window reveals but it’s a transferable hack

[@robwright3064]

Wow, slick!!

[@oneconsc3333]

The drywall screw trick I've used many times. Great for stair nosing that doesn't line up with flooring. We could use better tradesmen here😄

[@tc9148]

Would love to see you do a video on extension jambs for wood windows. How do you attach the extension jambs to the window jambs?

[@muddywater6856]

Nice! Feathering the drill speed is the key to speed.... I have always put the screws in with the impact as close as possible, then fine tuned with a regular screwdriver. Coarse thread screws are quicker to adjust with the screwdriver.... (I still carry my Yankee screwdriver from the 70s also 😀) Will try the drill on the low speed...seems much easier. Use the same method on wallcaps etc. with a level.

[@InsiderCarpentry]

I used to do the same thing with a manual screwdriver but found the drill on 1 speed to be much faster and easier. Try it out!

[@Whoisddepew]

Aahh andersen 100 series fibrex windows is what you have there. Andersen windows are all just about the easiest Windows to put jam extensions on especially their would models like 200 series 400 series and a series because they have a channel in the frame that allow you to line the jam extension up with the perfect margin if the window didn't already come with the jam extension on it. But the windows you are doing don't come with the jam extension generally but still very easy product to work with. Looks good man!!

[@turbinepower77]

Exactly the way I used to do it.

[@joshuamatheron1]

Great work. Guessing the window guys did a decent job regarding the reveals and everything being plumb. Most I come across are way out. Having to do each one differently.

[@rickowens4397]

I learned that technique back in the '70's when framing protocols went from 2x4 to 2x6 during the oil crisis and codes increased the R value in walls. Before window manufacturers tooled up. I would think small gap and a bead of caulk at the extension /window joint would help with expansion/contraction differences.

[@rickobbink4674]

Did the same in the 70's but screw guns weren't much then. We used roofing nails.

[@ericmedrano77]

Dude, those smooth and mellow jams though.

[@andriy_moskalyk]

Omg, u are the best