Author Topic: Flashing around windows for steel siding...  (Read 8932 times)

0 Members and 1 Guest are viewing this topic.

Offline Ernest T. Bass

  • "One in the same, 'Bass' is the name!"
  • Senior Member
  • ****
  • Posts: 982
  • Location: Da' U.P., eh?
    • Our Family's Blog (cordwood house building and homestead-related stuff)
Flashing around windows for steel siding...
« on: August 12, 2011, 01:12:05 PM »
Hey guys, I've been trying to figure this out for a while and finding very little info.. We're installing steel (barn) siding on a new residential building. The walls are conventional 2x6, OSB sheathing, housewrap. The windows are typical vinyl w/ integrated J-channels. We've used flashing tape over all of the nailing fins (under the bottoms, of course..). We were told to just cut the steel siding to fit into the integrated J-channels on the windows, but I see that as a huge leak potential. Any water running along the bottom of the window J can drain right behind the siding. I think a drip cap over the top would help, but not completely resolve the problem. The guy at the building supply says to install separate j-channel around all of the windows and caulk to that, but I don't really see how that changes anything. Any ideas?

Thanks!

Our family's homestead adventure blog; sharing the goodness and fun!

Offline Don_P

  • Journeyman
  • *****
  • Posts: 3,036
Re: Flashing around windows for steel siding...
« Reply #1 on: August 14, 2011, 05:52:40 AM »
Mainly I'm bumping this.

Have you checked manufacturer install details? Give them a call as well.

I agree with a drip cap up top, I'd slit it in a few inches beyond each side. The sides could have some type of custom trim bent that would slip into the J and lip over onto the face ending in a flat hemmed edge that could have butyl tape on the back of the hem which would all be screwed thru the hem, the siding and into the sheathing. Forming a side casing. The trouble there is where the ribs land.

I'd make sure to have a bottom flashing at the base of the wall and a positive way to drain anything that gets behind there.

I'd PM PEG if this doesn't catch his eye, they did a metal siding job recently. He might have some details that worked.

Offline PEG688

  • Master Craftsman
  • Journeyman
  • *****
  • Posts: 3,515
  • Whidbey Island , Wa.
Re: Flashing around windows for steel siding...
« Reply #2 on: August 14, 2011, 06:49:17 AM »

 We used a rain screen wall with the windows stood off 1/2" on PT ply battens around the window and door opens .

 We taped the "Rain Shield" building wrap with Tyvek flashing tape

 http://www2.dupont.com/Tyvek_Weatherization/en_US/products/residential/resi_tape.html

 Bottom first , set window , sides the over lap the head piece over the top end the sides , the head piece is under the building warp above ( slice the wrap at a 45 deg angle flip it up , run the top piece of tape , flip the wrap back down over the top.


 On the metal we used a " J " channel at the top like Don P said run it a bit long past the side J channel so the drip line where the water runs out is beyond the side

  The bottom we cut to fit between , the sides ran down , we had out roofing company do the metal siding, they bedded the bottom in Sikaflex  caulk , they did a horrible job of caulking , which is what I'd expect from roofers, we had the painters go back and clean up the mess and re-caulk , I haven't seen what that looks like , I go back to that job to do a couple of pick-up jobs on Tuesday so I'll see how it turned out.


  Hope this helps , but yes that bottom edge is a bugger on metal siding , we added the rain screen wall due to condensation fears , but having that space behind there made me feel better about the window details.

 Good luck!
When in doubt , build it stout with something you know about .

Offline Native_NM

  • Senior Member
  • ****
  • Posts: 719
Re: Flashing around windows for steel siding...
« Reply #3 on: August 14, 2011, 08:53:26 AM »
We put a large metal building (annex) at the yard.  The walls are ribbed metal over metal framing and horizontal purlins, house wrap, and insulation.  The supplier provided window frames specific to the panel design.  Maybe the manufacturer of the siding has a product specific to their siding.

New Mexico.  Better than regular Mexico.

Offline Ernest T. Bass

  • "One in the same, 'Bass' is the name!"
  • Senior Member
  • ****
  • Posts: 982
  • Location: Da' U.P., eh?
    • Our Family's Blog (cordwood house building and homestead-related stuff)
Re: Flashing around windows for steel siding...
« Reply #4 on: August 14, 2011, 01:02:06 PM »
Thanks for the advice, guys. There's nothing special about this metal.. Just your typical pole-barn 5-rib/exposed fastener stuff. I looked up many install guides and really didn't find much that applied.

Don, I've got your same concern about where the ribs will end up landing... I can see caulking it up pretty good if the spacing cooperates, but what's the chance of that happening? ;) I'll most likely have ribs splitting on the edges of the openings...

Well, we'll definitely use the extra-long rain cap detail (sounds tough to get a perfect cut-and-fit), and we'll get the panels caulked as well as possible, especially at the bottom.. We'll have a rat-guard flashing at the bottom of the wall that'll let water out from behind.

What about that 2nd j-channel wrap that was suggested to us? Does that sound like it would have any advantage at all? I just see it as a bunch more penetrations through the window flashing tape. PEG, were you talking about extending the side j-channel down past the the bottom j a little ways? Sounds like that would help direct water downward.. More tricky "slitting" of the metal though, and I've never seen it installed that way.

Our family's homestead adventure blog; sharing the goodness and fun!

Offline PEG688

  • Master Craftsman
  • Journeyman
  • *****
  • Posts: 3,515
  • Whidbey Island , Wa.
Re: Flashing around windows for steel siding...
« Reply #5 on: August 14, 2011, 07:02:15 PM »

What about that 2nd j-channel wrap that was suggested to us? Does that sound like it would have any advantage at all?

  Only if your the guy selling the J channel ;)
[/color]



 PEG, were you talking about extending the side j-channel down past the the bottom j a little ways? Sounds like that would help direct water downward.. More tricky "slitting" of the metal though, and I've never seen it installed that way.



  No, I was thinking the head piece could extend a bit past the sides , even if it's only 1/2" or  a bit less, just so the water that gathers in the channel is dropped off away from the long vertical seam that will be there. And yes you'd need a short kerf for the J to extend into, no big deal. 
When in doubt , build it stout with something you know about .

Offline JRR

  • Senior Member
  • ****
  • Posts: 893
  • 1000', Southeast, USA.
Re: Flashing around windows for steel siding...
« Reply #6 on: August 15, 2011, 04:47:30 AM »
Its probably possible to field-make a couple of transition pieces, left hand and right hand, that are corrugated-to-flat transitions.  I can visualize these going under the ends of the "J" flashing for better water control.  Not perfect, still need caulking ... but better.  If the corrugated stock is not too long, you should be able to flaten some of it with 2x's and c-clamps.  Finish off with rubber hammers on work bench.

Offline Ernest T. Bass

  • "One in the same, 'Bass' is the name!"
  • Senior Member
  • ****
  • Posts: 982
  • Location: Da' U.P., eh?
    • Our Family's Blog (cordwood house building and homestead-related stuff)
Re: Flashing around windows for steel siding...
« Reply #7 on: August 15, 2011, 04:58:24 AM »
Alrighty then.. I might get stuck using the extra J anyway--don't know if I'll be able to convince the guy out of it. I'm just thinking that if I was stuck using it anyway... You know how the side J's normally come down to the bottom of the lower J, and then you typically make a little notch in the bottom there and fold it over?



If that little tab was bent back down over the metal after installation and then caulked, seems like it would help keep water away from the window bottom, where it would get into trouble...

JRR; Not quite sure if I'm understanding your idea.. By the flattening, are talking about the ribs that fall under the window?

Our family's homestead adventure blog; sharing the goodness and fun!