To avoid these ads, REGISTER NOW!

Vinyl siding advice please

Rob D

Member
Joined
Aug 20, 2023
Messages
9
I am wrapping up a new shed build. In the materials that the gentleman sold me from the siding company, he says that you install a J trim under the soffit and your last row of siding tucks into the J trim... Would it not be loose and floppy in the edge that goes into that slot in the J trim?

Sorry for the dumb question,but I'm new to this.
DSC_0819.JPG
 
To avoid these ads, REGISTER NOW!

CraigStu

Well-known member
Joined
May 22, 2014
Messages
4,012
Location
Blacksburg, Va
Yeah seems to me it will be loose. I hope someone w/ experience will chime in because all I can suggest is some clear silicone.
 

The Cobbler

Super Moderator
Staff member
Joined
Oct 24, 2013
Messages
25,812
Location
Niagara Region, Ontario, Canada
depending on where the cut ends up on the sheet, you use J and/or or undersill
basically, if you're just cutting off the nail flange you use undersill inside the j trim to take up the space
if you cut deeper in tot he panel, you just need J

poster above was typing the same time I was. his pictures show it well
 

tmp

Active member
Joined
Sep 12, 2023
Messages
41
You have a somewhat tricky situation with the Dutch lap siding. You need undersill / finish trim to clamp the cut edge in place, but with the depth of the Dutch lap you can’t just slap on standard undersill / finish trim tight to the sheathing. You will either need to shim out behind the finish trim to catch the edges at the right depth, or if you can find it you can use a “dual undersill” trim that will accommodate the extra depth. It is harder to find dual undersill in a matching color.

This only really matters on the front and back wall. On the side walls you will get plenty of fasteners through the nailing fin, and you can just tuck your mitered ends under a piece of J channel with no concern.

Don’t caulk it. Don’t put screws through it. Both of those will cause the vinyl to buckle.

Dual undersill example - https://www.menards.com/main/buildi.../vt2dut21/p-1444437164863-c-1495119088651.htm

There’s a recent JLC video that reviews the best practices for vinyl where this is discussed with some graphics that might help it make sense - https://players.brightcove.net/403604197/default_default/index.html?videoId=6359627970112
 
To avoid these ads, REGISTER NOW!

impactims

Well-known member
Joined
Nov 24, 2011
Messages
1,168
The very top piece of vinyl siding is always "loose."

It hooks onto the piece below it and slides into the j channel above it. No fasteners of any kind. I need to periodically push my tops pieces back into place as they shift downward a little. Something I am stuck with having to do when using vinyl siding.
 

PCustoms

Well-known member
Joined
Jul 23, 2011
Messages
22,289
Location
VT
The very top piece of vinyl siding is always "loose."

It hooks onto the piece below it and slides into the j channel above it. No fasteners of any kind. I need to periodically push my tops pieces back into place as they shift downward a little. Something I am stuck with having to do when using vinyl siding.
Yes, most of it it loose.

If it was installed correctly, it wouldn't be.
 

impactims

Well-known member
Joined
Nov 24, 2011
Messages
1,168
Yes, most of it it loose.

If it was installed correctly, it wouldn't be.
“Loose” as I said it could be more correctly stated as “floating.”

The top piece of siding is floating in the sense that it is not fastened down via nail flange. This is how it is designed.

It stays into place by hooking the piece below it and sliding into the piece above it.

Not ideal, but that’s how it’s made.

Overall I’d say vinyl siding is not a very good system, for many reasons.

I had vinyl siding. I recently replaced it all with James Hardie fiber cement.
 

cgrutt

Well-known member
Joined
Mar 4, 2016
Messages
8,169
If you use the top trim piece and put a few crimps along top edge with a crimping tool it will pretty much lock into the trim piece. It will still be floating but shouldn't fall out.
 

Whitworth

Well-known member
Joined
Dec 26, 2011
Messages
2,082
Crimp tool. Needs a couple practice pieces to position the crimp tabs just right.
Usually a matter of just shy of engaging the trim, and then a firm push up to click in place.

But your situation is at an angle, so a bit of a challenge perhaps.
 

The Cobbler

Super Moderator
Staff member
Joined
Oct 24, 2013
Messages
25,812
Location
Niagara Region, Ontario, Canada
the vinyl trim expands and contracts at the same rate as the siding does. if it can float and your siding is attached to it ( and not any substrate ) there are zero issues . also some screws up from the bottom lip into the lower pc of siding helps too
 
To avoid these ads, REGISTER NOW!
Top Bottom