How To Install J Channel Under Existing Siding

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  1. How To Install J Channel On Existing Siding
  2. How To Install J Channel For Siding
  3. How To Install Vinyl Siding
  4. How To Install Exterior Siding

Undersill trim, for instance, is installed under windowsills or other horizontal projections and grasps the top edge of the siding panel below it (see Installing window trim). J-channel receives the ends of siding panels where they abut windows, doors or other walls. Jun 28, 2016  Yes, that was my original thought. We discussed with the siding contractor and he was going to use a 3' j-channel to give the effect of a wider window trim. Now that I'm keeping the siding, I'm looking for the easiest way to achieve a wider window trim.

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GETTING STARTED

Installing new construction windows in an existing home may sound like an intimidating task. But if you follow these step-by-step instructions, you'll be a window installation wiz in no time.

This tutorial is for installing windows with integral nailing flanges with sheetrock return interiors. Wood windows with brickmould or flanged windows with wood interior casing have a slightly different process. The basics are the same however. So let's get started.

TOOLS & SUPPLIES NEEDED

  • Cat's claw/nail puller
  • Framing hammer
  • Pry bar
  • 2 foot level
  • 4 foot level (doubles as a straight edge)
  • Tape measure
  • Circular saw
  • ½' or ¾' chisel
  • Caulk gun
  • 8d or 10d galvanized nails
  • Nail set
  • Siliconized acrylic caulk
  • Exterior trim boards (i.e. cedar, smart siding, or PVC)
  • Standard window flashing
  • Power miter saw
  • Table saw
  • Jigsaw (not on every application)
  • Flexible window wrap tape (tar backed & self-adhesive)
  • Utility knife
  • Pencil
  • A positive attitude and gumption

GOING BUH, BYE

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STEP ONE: REMOVING THE EXISTING WINDOW

Let's assume the new window has been measured for and purchased.

How To Install J Channel On Existing Siding

How To Install J Channel Under Existing Siding
  • Using the cat's claw, remove the existing nails from the current trim boards framing the window.
  • Cut any existing caulk beads around the trim boards.
  • Pry the trim boards slowly from the exterior and remove.

You should now be able to see the existing siding and complete frame of the old window

  • With the circular saw, set the blade depth just deep enough to cut the thickness of the siding. Setting the blade too deep will make cutting more difficult; too shallow and it won't clear.
  • Make your cuts as straight as possible and about 1' beyond the edge of the existing window's nailing flange.
  • Remove all nails between your cut and the edge of the siding.
  • Remove the old siding keeping as much intact as possible. You may wish to re-use it later.
How To Install J Channel Under Existing Siding

You should now be able to see the entire window and flange with securing nails exposed.

  • Begin removing all nails from the existing window's nailing flange. I usually pull the bottom and sides first and finish with the top. You should probably have someone assist you once the final nail is pulled to keep the window from falling on you.
  • Remove the old window from the rough opening. A gentle nudging might be needed, but the unit should come out easily.

PREPARATION, PREPARATION!

Click thumbnail to view full-sizeSiding

STEP TWO: PREPARING THE ROUGH OPENING

  • Measure the distance from the backside of the new window's nailing flange to the edge of the new window's frame. Our window has a measurement of 1 7/8'.
  • Measure the distance from the outside of the rough opening's framing stud to the edge of the interior sheetrock return. The difference between these two measurements determines how much sheetrock needs to be removed. Our installation needed 1 1/8' removed from the interior sheetrock.
  • Using your tape measure, mark this distance on the sheetrock at various points and mark a line with a straight edge.
  • With your straight edge as a guide, score the line a few times with your utility knife.
  • Remove the excess sheetrock from all sides and clean up the edges.
  • With the window wrap tape, cover the entire length of the bottom sill plate and about 3-4' up each side. This will provide a waterproof dam on the sill in case of any water infiltration.

You're now ready to install the new window.

PLUMB, LEVEL, & SQUARE!

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STEP THREE: INSTALLING THE NEW WINDOW: PART 1

  • With assistance, (and the window locked) center the new window in the rough opening and check for square. This is done by placing your tape measure on the top left outside corner of the window frame and measuring the distance to the bottom right corner. Record this measurement.
  • Next, take a similar measurement from the top right outside corner to the bottom left corner.
  • These two measurements should be within 1/8' of each other. If not, you'll have to adjust accordingly by shifting the window right or left in the opening. I tend to shift in increments of 1/8' with good success.
  • Once the unit is square, soft nail the top left corner to secure.

NOTE: DO NOT HARD SET ANY NAILS UNTIL THE WINDOW IS PLUMB, LEVEL, AND SQUARE!

  • With the 2 foot level, check the sill plate for level and shim if necessary.
  • Check for plumb on the side you soft nailed and adjust accordingly.
  • Check for plumb on the right side and adjust accordingly.
  • Recheck for square.
  • Once both sides are plumb and the sill level, you can soft nail the sill. I usually put nails in each corner and the center.

NOTE: Chances are pretty good if you properly squared the window, the sides and sill will be plumb and level.

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STEP FOUR: INSTALLING THE NEW WINDOW: PART 2

  • Recheck both sides for plumb, the sill for level, and the unit for square. (Sounds like I'm beating a dead horse, but this is the key to proper operation of the window).
  • Once all the measurements are correct, you can hard set each nail and add additional nails. Nail every 8' on each side, every 6' on the sill, and allow the top to float.
  • With window tape, cover the new flange and extend to the edge of old siding.
  • Nail into place, either new siding (ripped to size with your table saw), or the existing siding if not overly damaged, and install over the new window's flange to the edge of the existing siding.
  • Caulk any major voids.
  • With window tape, cover up all seams; to the edge of the window to about 1' past the outside seam.
  • Back caulk the tape to the edge of the window on all four sides. This is done as prevention against any water that may infiltrate the primary trim boards and caulking.

WE'RE GETTING CLOSE.

How To Install J Channel For Siding

  • Flash the entire top of the new window with standard window flashing. Make sure you extend the flashing the width of each side trim board. (If your new window rests directly under a wide soffit, you can usually skip this step).
  • Cut your trim boards to size and notch as needed; as if in under a soffit.
  • Nail the trim boards in the following order: 1) Top 2) Sides 3) Bottom.
  • Nail each trim board into place.
  • Caulk the top and sides of each trim board but not the bottom edges. This is done to ensure proper drainage.

YOU'RE DONE!

Give yourself and your help a nice high five and move on to the next window.

How To Install Vinyl Siding

  • This is the application everybody desires to have as they go about their daily activities. It follows the rugged sea-coast and has a lot of areas to park and take walks or fly a kite in the sea breeze. It also had Bluetooth 2.1 support and the ability to search all saved SMS and MMS. Mobile app development is just like any other professional service - you want to be assured they know what they are doing.In all of this I have to work with a lot of different applications. The article speaks about the various ways to simplify our lives with the help of mobile apps. However, it is not so easy to create new applications for mobile devices.business mobile apps, smartphone app, app sitesblogsinternet marketing, internet and businesses online, marketing, business, mobile computing, computers and technology, health, finance, video games, tech tutorials, science, tech, mobile applications, weight loss, software, computers, communications, cell phones, technology, outsourcing, mobile cell phone, programming, information technology, web development01-1Best Android Apps For Free Help With Your FinancesDo some research on current trends and what your target users want (and don't want!). It up loads your app with beautiful graphic that have multi dimensional effect. They allow you to make the best of your mobile phones.The Google Play keeps eye on how many downloads an app is getting in the first few days. You may get the user-reviews of a big number of restaurants in America using Yelp. We still need big computers to do the serious stuff. I remember way back in the early 90s when IBM AS/400 application development was in huge demand.

  • I am replacing all the windows in my home in a similar manner. My question is, what do you do about foam insulation between the window frame and the rough opening. I want to get that in there to manage air flow but short of cutting more of the drywall away and having a 3/8' gap or so between the window and drywall return, I don't know how else to get it in there. Any ideas?

  • It’s really a great and useful piece of information. I am satisfied that you simply shared this helpful information with us. Please keep us informed like this. Thanks for sharing.

  • I am installing aluminum thermal barrier new windows in rough openings on a new construction sun room. I have conflicting theories about what goes under and on top of nail flanges. Should the 7/16 inch sheathing go under or over the nail flange? I plan to use foam backed vinyl siding which I presume would have to be on top of nail flanges? Entire outside wall is 7/16 inch sheathing and the foam backed siding which is one inch thick. Sure would like to hear about. Already read about thermal aluminum windows not all that energy efficient

  • My windows in my home are slowly starting to need to be replaced. A lot of them won't shut all of the way so cold/warm air will trickle in. I would rather not have to have someone install it for me, so this step by step process has been really helpful.

  • Great hub! Installing new windows can be a tricky task to master. Although these tips are helpful I think I'll stick to doing what I do best and hire the pros for any kind of window installation. Regardless, your hub gives property owners a good impression of what this type of home improvement entails. ~ Voted up.

  • I really liked the tips here. I think they are useful. Instead of paying so much money to professionals, there are thousands of things you can do on your own and they are quite simple. I come from the field of construction and I am always surprised to learn that there are so many simple things people can do, but they prefer to rely on others.

  • Peg,

    You place the Sticky tape over the flanges in this order: bottom, sides, then top and then trim as usual. Hope this helps.

    Rob

  • I have t 11 siding I do not have any house wrap or moisture barrier under the siding I have installed sticky back window tape on the sill have calked across the top and down the sides then set the window how do I complete the flashing with the sticky tape

  • This actually doesn't seem super difficult. Maybe we can get away with doing it ourselves and not having to hire a residential window installations Portland OR company. I am curious on the price of doing it yourself though. Any information would be great! http://joesglassinc.com

  • Go for the professionals they know what to do. I have been calling to the professionals. I am a very satisfied customer.

    New Jersey emergency board up- http://waterbasementnj.info/

  • hi rob is the there a diffrents between new constration windows and pocket one besides the nailing flang and is it standard practice to use the window tape around it or is that an extra thanks

  • Great hub! We just bought 2 new construction Andersen 400's to install in place of the original single pane double hung in our 1963 home. Rough opening matches with the Andersen specs. My question is how to handle the flashing that I'm going to need to remove once I install the new windows. Of concern is the wide aluminum siding. Will I be able to remove that flashing without damaging the siding? Any ideas? Thanks. AW

  • Thank you for your quick and helpful response. Looks like it is a bit complex than what I thought. Yes they are original wood windows. I am thinking of installing American Craftsman(HD)3000 Double-Hung Vinyl Windows. Brickmoulds were also rotten near sill. How to avoid wood exposure outside? Do you have any other suggestions?

  • Thank you so much for this helpful article. I have a double hung wooden window with rotted outer sill. Outer window trim is covered with brick mould and vinyl siding around it and foam board behind. I am planning to install new vinyl double hung window with flange. How do I install window flange inside vinyl siding?

  • RE:Make your cuts as straight as possible and about 1' beyond the edge of the existing window's nailing flange.'

    I have removed the exterior trim and the T1-11 runs right up to the egdge of the window. How do I know how far the flange extends so I can cut 1' beyond that?

    Thanks!

  • This the by far the best how to article on installing nail fin windows for replacement. I have house wrap under my t 111 it was impossible to cut the siding without cutting house wrap. I've read that house wrap joints must be taped. I found that it was impossible to tape joint between the existing house wrap and new window flashing. I did the next best thing which is to use 6' wide paper flashing and tuck it under the existing flashing. I also taped the nail flanges with flashing tape. Does anyone know a better way to join the house flashing with new flashing or better way to cut the t 111 without damaging the house wrap?

  • Thank you so much Rob for the instructions. I am a novice for sure. I am building small cabin . I closed it up for winter and am now spending time learning how to install windows for the spring. I am really grateful for all the time and effort you put into this. Peggy

  • fantastic schooling !

    You're helping to make the world go round.

    Thanks man !

  • I need to replace the three windows on the back of my house. It's north-facing with no eave. The sills have rotted. I've purchased Andersen TW 400 series - new construction windows with nailing fins.

    If I have T-111 siding and foam board sheathing under that - no existing nailing fins or flashing, would you cut the siding and foam board down to the framing and then install as you've said?

    Could I just apply flex sheathing to the bottom of the rough opening and nail directly to the siding, apply flex sheathing all around and a drip cap and then just use extension jambs inside?

  • Thank you so much for this helpful article it was instrumental in our window project.

  • Quite detailed your instructions are. Removes the fears, I imagine, in the minds of those who want to do these themselves. Good stuff. I'm into home improvement, too.

  • Rob, thank you for this wonderful, very precise and highly practical hub! I also like how you use your tags about this particular niche market. Try to add them many more(long tail ones).

How To Install Exterior Siding

  1. ↑https://www.vinylsiding.org/vsi-resources/why-vinyl-siding/
  2. ↑https://www.homeadvisor.com/cost/siding/vinyl-siding-installation/
  3. ↑https://www.popularmechanics.com/home/how-to-plans/how-to/a169/installing-vinyl-siding-easily/
  4. ↑https://www.bhg.com/home-improvement/exteriors/siding/an-introduction-to-installing-siding/
  5. ↑https://www.popularmechanics.com/home/how-to-plans/how-to/a169/installing-vinyl-siding-easily/
  6. ↑https://www.popularmechanics.com/home/how-to-plans/how-to/a169/installing-vinyl-siding-easily/
  7. ↑https://www.popularmechanics.com/home/how-to-plans/how-to/a169/installing-vinyl-siding-easily/
  8. ↑https://www.bobvila.com/articles/how-to-install-vinyl-siding/
  9. ↑https://www.popularmechanics.com/home/how-to-plans/how-to/a169/installing-vinyl-siding-easily/
  10. ↑https://www.popularmechanics.com/home/how-to-plans/how-to/a169/installing-vinyl-siding-easily/
  11. ↑https://www.provia.com/images/img/pdf/Vinyl_Siding_Installation_Manual_English2.pdf
  12. ↑https://www.provia.com/images/img/pdf/Vinyl_Siding_Installation_Manual_English2.pdf
  13. ↑https://www.americanladderinstitute.org/page/Ladders101
  14. Time-Life Books. (1989). Fix It Yourself: Roofing & Siding. Alexandria Vir.:St. Remy Press.