20' wide 1 1/12 cottage: Loft floor joist qustions

[BigMish]

Are the joists doubled up directly next to each other or sandwiching the stud?
For the open ceiling: you specify "1/2x2 TRIM@BOTTOM DBL 2x12" but 2" isn't enough to cover the width of the joists whether they are sandwiching the stud (4 ½" width) or not (3"). Is that dimension wrong or am I reading it wrong?
Just to confirm I understand this right: the ledger is placed in a notch that was cut out of the stud, right?

Thanks, M

[peg_688]

I don't have that plan but I'll stab at it anyway, just for fun.

I'd guess the 1/2 x2" trim is just that trim to cover either the drywall or wood paneling connection on the surface / interior around the beam / built up dbl joist.

The dbl joist would be nailed together , in a classic 3 , 2 ,3 nailing pattern so both joist would be  on the same side of the stud , nailed together,  making a 3" wide dbl. joist.

And yes the ledger would be let into the studs , you might look at this thread about how that can be done and some questions that where raised about using a full 1 1/2" x 5 1/2" (2x6) for that ledger.

http://www.countryplans.com/cgi-bin/yabb2/YaBB.pl?num=1144724922

[jraabe]

PEG's right about the ledger, and the loft beams in the Loft Framing Plan (sht. 5) are double 2x12 joists that sit on the let-in ledger and are nailed into the side of the studs. The 1/2 x 1 1/2 trim piece goes on the bottom of the beam covering the joint and gives a 3/4" reveal on each side. You could trim this with something else you might like better. If you are matching the finish floor height to the joist and subfloor system you may need to notch this double 2x12 beam to get the decking to be level with the subfloor.

[BigMish]

I'm having trouble imagining how that trim would look with the ½" reveal. Any one have any photos they could share of this detail?

I read and re-read the sentence "If you are matching the finish floor height to the joist and sub floor system you may need to notch this double 2x12 beam to get the decking to be level with the sub floor." But I just can't seem to understand what you are saying. Can you explain further?

[John Raabe]

Hint:

A 2x12 with 3/4" plywood on top is a different height than a double 2x12 with 2x6 decking on top. If you want these two types of floors to line up so you could, say, put carpet over both seamlessly you would have to notch the deeper one where it rested on the ledger.

Don't worry about the trim... You will only have to consider that far later and at that time you can cut a short piece, tack it up there and see if you like it. If you don't you'll figure something else out.

Remember the first rule here, "work from the general to the specific".

[BigMish]

OK, never mind about the trim but now you've got me confused, what do you mean with the 'A 2x12 with 3/4" plywood on top is a different height..."? :-/

[glenn kangiser]

If the loft joists were covered with plywood that was 3/4 thick then you continued out over the area that was open below putting 2x6 t and g decking then the joists supporting the 2x6 would have to be notched to drop them down appx. 3/4" to match the top of the floor  levels since the 2x6 is about twice as thick as the 3/4 ply.

[BigMish]

I'm wondering about the joists for the loft: isn't a double 2x12 16" o.c. overkill? I ask this because the joists for the first floor are only single (not double)  2x12s 16" o.c....

.M

[John Raabe]

Look at the framing plan and I think you will see that the double 2x12 beams are spaced twice as far apart. These beams have the heavier decking on top to span that wider spacing.

[BigMish]

On my version on the Loft Floor Details it says "2x12 joists @ 16" o/c" should this be 32"?

[PEG688]

On my version on the Loft Floor Details it says "2x12 joists @ 16" o/c" should this be 32"?

[highlight]The joist spacing is a IF  or OR option.[/highlight]

IF you choose to use [highlight]2x T&G decking[/highlight] you'd use the DBLed joist 32" OC.   The span / distance between joist is wider becauce te 2x decking can span further .

[highlight]IF you use  a  3/4[/highlight]T&G sheet good type subfloor your joist would be 16" OC single joist. As the 3/4" goods will not span 32" .

So either or depends , driven by what subfloor you select.  

 
 

[BigMish]

Got it!
Thanks