HomeSealed... You are correct, they did not use flashing tape because of the brickmold. The put some down on the sill before hand, but all they did was use caulk around rough opening before they set the window in. Do you suggest something different?

I planned to do J-channel just like they did. Cut and installed before sliding the window in. My thought was to just let it loose and not fasten it down.

The custom window that i'm ordering is offered with a brickmold.

My use of the term flashing was referencing a metal head flashing/drip cap as pictured below. I'll reiterate that I'm not criticizing the install in the video as it appears to be recorded more for sales or promotional purposes than for installation instructions, but that is something that was not pointed out in there . In reality it is a must. If you simply slide j channel on top of this new window and caulk the J to the window brickmold, you will have yourself an opening that will leak. Install a head flashing over the opening, back caulk and tape to sheathing, lap housewrap OVER it. Then do not caulk the interface between the J and this new flashing. That is where moisture that gets behind the vinyl or aluminum siding (which it will) is directed OUT from the window opening instead of into it. Making this happen with aluminum siding is all easier said than done as the panels don't pop apart and back together like vinyl without a high risk of damage. You may run into nails in the siding panels near your newly cut ends which will make it extra tricky to slide J behind it, in addition to the fact that again, unlike vinyl, aluminum is nailed tight.

I would not float the J channel either, that is asking for trouble. You will want to try and get some trim nails in there in inconspicuous areas. Aluminum doesn't move as much as vinyl so that won't be a concern.

The use of the flashing tape in the rough sill in the video is fine, although that is a measure that merely serves to protect the wall cavity when a leak is present (which we of course are trying to avoid). Its basically CYA in that regard, but is generally recommended for the most comprehensive install. If done however, it is wise to install sloped pan toward the exterior so that water doesn't just pool or run backward toward the interior. That would completely defeat the purpose. Tacking down a piece of cedar lap siding works well.

If you are cutting the siding back, why not just run a flanged window in that case. Head flashing/drip cap is a must here as HomeSealed indicated.

Thank you for the details!

I agree that installing the head flashing will be difficult. I think i'll need to install the channel on the top first, then the sides and finally the bottom. Once that's in, then i'll need to somehow get the head flashing in and installed following the steps you noted.

I wonder why they didn't add that head flashing in their video? Even in the final shots it does not have one installed. I called the company a couple weeks ago and he was very helpful with tips. He did not mention anything about the head flashing.

What specifically about the head flashing gives the window and/or it's opening more protection than just using a j-channel? It's not that i don't agree it gives more protection, just trying to educate myself on what makes it superior to just the j-channel as they illustrated.

Windows on Washington... If you cut the siding back enough to expose the old flange and then install a regular flanged window vs. a brickmold one, you will be left with a greater area that will need to be somehow covered.

They make larger brickmolds or just go back with 1x4 trim. If you are doing all this work to avoid a retrofit installation, why not just go full monty?

Not sure what "full monty" would be ?

I did think about just going with a normal flanged window and getting some vinyl brickmold. But i thought the built in brickmold would offer better protection. However, doing my own brickmold would allow for proper flashing of the entire flange plus easier install of the drip cap.... not to mention i could get the window 2 weeks sooner as well!

So if i go with the DIY route with the PVC brickmold, i've got a few questions.

Assuming the standard new construction/flanged window is installed into the properly prepped rough opening. I then tape the flange, install the J-channel and drip cap as explained above.

• How would you attach the PVC brickmold? Pre-drill and counter sink and then use screws and come back with caulk/putty over the screw heads?
• Do i apply caulk between brickmold and window seam?
• Do i put caulk between brickmold and j-channel?

Use Cortex Screws

You can back caulk it if you are clean about and will have virtually no line

Yes, you would normally caulk between brickmold and J-channel

You don't need to pre drill PVC, it can also be nailed on, I prefer to prefab pvc trim and install as one unit.

Well i ended up ordering a awning window with a standard nail flange (no built in brickmold). Gave him the rough opening dimensions and he subtracted 1/2" for each direction and that's what has been ordered. 2-3 week ETA.

Is there any particular brand or style of PVC brickmold i should use or is it just personal preference and what's available locally?

Also, i doubt i will find aluminum J-channel that matches my siding. So i'm thinking i'll just use white vinyl j-channel so that it matches the brickmold and window. Any thoughts on this?

Good news! The window i ordered back in December arrived last week.

Bad news....the window being replaced shattered overnight due to the extreme cold we are having (it was -22 degrees this AM, not including windchill).

More bad news...i need to do my first aluminum siding window install in this weather :( But on the upside it's supposed to be 30 degrees above zero this weekend!!

So bare with me, but i would like to do a full run through of my install to make sure i'm not forgetting anything process wise or materials wise.

YOUR HELP WILL BE GREATLY APPRECIATED HERE!!

1. Measure the width and height of the new window (not including the flange). Measure the width of the PVC brickmold and multiply it by 2. Add the total of the brickmold plus 1/4" to each dimension from the window measurement.
2. Cut through the aluminum siding with a circular saw to create an opening in the siding that equals the measurements from step 1. This should expose the flange from the old, originally installed window.
3. Remove all the old pieces of the window (nails, nailing flange, etc.)
4. Install adhesive backed flashing tape on bottom and sides of rough opening.
5. Caulk edges of opening that the nail flange will cover and Insert window and nail in place.
6. Cover the nail flange with adhesive backed flashing tape...bottom, then sides, then top.
7. Back caulk and Install head flashing, cut to the width of the window. Nail in place and then cover with adhesive backed flashing tape.
8. Cut and install J channel around aluminum siding edges.
9. Cut and fit PVC brickmold. Back caulk it as well as caulk the edge that touches the window. Nail or screw brickmold in place.
10. Caulk seam between j-channel and brickmold.

Well i think that's it right? Did i miss anything, materials or processes?

Also, wondering if this dremel cutter would work good for cutting the aluminum siding? Seems like this would be much easier to manuver vs. my circular saw.

UPDATE:

• Purchased the dremel cutter noted above
• Have read that when back caulking the nail flange (step 5 above) you should not caulk the bottom flange
• Also read not to flash tape the bottom nail flange (step 6 above)

Some more questions came to mind:

• Should the drip cap go between the window and the brickmold, or should it go on top of the brickmold and in between it and the j-channel?
• How do i avoid cutting into the house wrap when i cut my siding?
• Any tips for sneaking the flashing tape under the siding since it's 4" wide and only ~2" will be visible/exposed?

I think a circ saw would be better, what ever it takes to get it done and what you're comfortable with is a good choice.

no caulk and tape on bottom is to allow water escape, but you should have a sill pan, google dupont window flashing for video.

drip cap goes on top of brickmold and between the J. I would flash this directly to sheathing.

Not cutting the house wrap can be tricky, control you're depth as best as possible.

Just because you're tape is 4'' wide doesnt mean it has to remain that way, cut it down to what you need.