Small Cabin

Small Cabin Forum
 - Forums - Register/Sign Up - Reply - Search - Statistics -

Small Cabin Forum / Cabin Construction / Loft at 8 ft with 10 ft walls
Author Message
grover
Member
# Posted: 28 May 2013 23:28
Reply 


I want to do 10 ft side walls and start the loft floor at the 8 ft height so I can have ample headroom in my loft. Can this be done properly with 2 x 4 walls or do they need to be 2 x 6? I think it can be done a couple of ways. The one I think may be the best is by sistering a 8 foot 2 x 4 or 2 x 6, whatever the wall is, to the existing 10 foot 2x. This creates the ledge to rest the floor joists for the loft. I will have a few walls under the loft that will run perpendicular to the loft joists that will support the center of the loft being my plan is 24 ft wide.
Is this the best, easiest, cheapest way to support a loft?

Just
Member
# Posted: 29 May 2013 07:53
Reply 


The short answer is it's not recommended .

Aaron29
Member
# Posted: 29 May 2013 08:05
Reply 


Here is a camp build that I am loosely copying(although not because of the 10' walls)

may give you some ideas.

http://www.small-cabin.com/forum/6_1145_0.html

OwenChristensen
Member
# Posted: 29 May 2013 08:08
Reply 


Are your floor joist full span, 24' ? It's all about the load. on a 12' wide, you can notch a ledger board into a 2x4 10 stud to carry the floor joists. Yes, your idea will work too.

bldginsp
Member
# Posted: 29 May 2013 08:32
Reply 


I don't think you need to sister the existing studs. I would use 2x6s for the wall studs, then put a ledger against them and use a lot of lag bolts to attach the ledger to the 2x6s. You can notch for the ledger as one person suggested, but I'm not sure it's necessary. So long as the loft floor is not taking any roof load, and is partially supported by walls beneath, a bolted ledger at the outer walls is all you need. That's what's done for first floor additions all the time. But- you need to look at the span for the loft joists closely, which we don't know from what you told us. And use hangers on the ledger to support the loft joists.

2x4 studs will work for a 10 foot wall, but that's minimal, I'd suggest you use 2x6 in any event.

grover
Member
# Posted: 29 May 2013 10:39
Reply 


Not recommended means 2 x 4 x 10ft walls not recommended?

Thanks Aaron, I'll check it out.

None of the floor joists will be full span 24 ft. Main level and loft both supported mid-span.

If I use 2 x 6 walls and a ledger board I will probably notch the ledger board into the sidewalls and use hangers for the joists. The sidewalls will be taking the roof load because I plan on using scissor trusses.

Thanks

MJW
Member
# Posted: 29 May 2013 10:45
Reply 


grover,

We did the 10 ft walls with loft floor at 8 ft and really like it alot. The loft is our 5 yr old's bedroom but has plenty of usable space and headroom for adults.

We did use 2 x 6s for the walls for both the added strength and ability to insulate.

grover
Member
# Posted: 29 May 2013 14:22
Reply 


If using 2 x 6's...Is it perfectly fine to do 24" on center instead of 16"?

241comp
Member
# Posted: 29 May 2013 14:29
Reply 


My cabin is 2x6 studs for 10ft walls and will have a loft planned at ~8ft. We chose to build with 16in spacing. I believe that you will be OK with 24in spacing instead of 16in spacing with 2x6 studs, however. You might consider what you're planning to use for siding and whether that dictates the use of 16in spacing.

grover
Member
# Posted: 29 May 2013 17:28
Reply 


Yeah, I'm afraid I would feel like I was building cheap if I did 24" on center but maybe not. Better insulating properties, more depth and less thermal bridging.

Truecabin
Member
# Posted: 29 May 2013 18:54
Reply 


24s is a pain in the butt, and a pain again when you kick yourself for saving a couple $4 studs.

MJW
Member
# Posted: 30 May 2013 10:33
Reply 


We went on 16 for ours.

When you calculate the number of 2 x 6s you save, it really isn't that much.

OwenChristensen
Member
# Posted: 31 May 2013 10:34
Reply 


Either size studs will hold the vertical load ok, but the 16'' centers will support siding or interior wall finish better. If you have sturdy siding or sheathing and say 3/4'' T&G paneling inside 24'' stud spacings are just fine.

optimistic
Member
# Posted: 31 May 2013 12:57 - Edited by: optimistic
Reply 


I did something similar. I have a 12'x12' cabin and my ceiling height is about 13'. I wanted to have as much headroom as possible in my loft.

Using a span calculator I needed to use 2x8 at 12" OC to span those 12'... This takes a lot of head room.

What I did instead: I made a triple up beam from 2x4' (12' long of course). I connected it with massive carriage bolt and construction glue. Then I connected a 2x8 ledger board to the wall so it is parallel to it. I used 2x8 for the ledger so the screws will be far from one another and not split the board. I used special construction screws made by GRK - amazing made in germany screws that are stronger than 1/2" lag bolts. I put two into each stud.. quite an over kill.. Ledger is held by about 20 of those screws.

Then I used steel hangers to hang 2x4's 16oc between my beam and ledger board - so the top of the 2x4s joist is flush with the top of beam and ledger board. The span was then only 5.5' which is nothing for 2x4.... Doing it this way - I saved head room and didn't need to use a supporting post in the middle. Basically the head room lost was 3.5" (2x4) instead of 7.5" would I have gone with 2x8s which would have been just enough.... Maybe I would have even had to do 2x10 losing even more head room.

Truecabin
Member
# Posted: 31 May 2013 16:56
Reply 


dont use a span calculator for a loft it is for floor span and live loads
if anyone tells you to use span calcs for a crawling headroom loft they dont know what they are talking about
you cant fit your 300 lb mother in law rushing to a heavy loaded fridge all day up there
newbys get so excited about spans but they dont know what it means
good for you avoiding 2x8s but you can take out about 16 of those special german bolts in the ledger and save them for another project

optimistic
Member
# Posted: 31 May 2013 18:43
Reply 


Better safe than sorry....

Those screws cost about $15... They are staying in there for that price.

you are right about load calculations with live loads. But I rather over build than under build.

ICC
Member
# Posted: 7 Jun 2013 23:14
Reply 


the real concern with doing a loft floor at 8 ft or so on a 10 foot stud wall is there are no rafter ties across the bottom of the roof triangle (at the weall tops). the loft floor joists do not count. many think they go, but they don't... it's more a case of wanting them to be okay because it makes a loft easy. The rafter forces outward on the 2 ft stud "extensions" put forces on the studs that you don't weant. unless you do a ridge beam of course. many people build that way though and many are lucky that they don't see wall spread and ridge sag. do what you want but it is not a great idea on something as wide as 24 ft expecially if there are snow loads.


btw, the GRK and Fastenmaster sructural screws are good screws where you want to be sure of load carrying ability. they do come with a pedigree of how many pounds can be carried. ledgers are always better sitting on a piece of lumber than depending on a fastener for load carrying though. norches work for load carrying but weaken the stud when it comes to those horizontal forces.

grover
Member
# Posted: 8 Jun 2013 19:46
Reply 


Sorry that I forgot to mention we are using scissor trusses so tying the walls together shouldn't be a concern, I don't think. I think the best answer is to notch a 2 x 8 into 2 x 6 sidewalls and rest the loft floor joists on the 2 x 8.

ICC
Member
# Posted: 8 Jun 2013 20:31 - Edited by: ICC
Reply 


engineered truss completely changes the game. the engineer / supplier should indicate how those are to be fastened to the wall top plate. also be sure to tell the engineer how the walls are to be constructed (kneewalls). scissors trusses often do have some horizontal outward component. not a lot but some is not unusual. depends on if the engineer is trying to design them with a lower price in mind or whether he strives to limit the horizontal loads. ask him / tell him all the details.

a 2x8 for a ledger is a waste of wood. you can balloon frame a two story house using a 1x4 let in to the wall studs as long as the joists sit on the 1x4 at each stud and are also face nailed to the stud and the studs are 16" OC. . Usually 3 - 16D nails through the 1x4 into the stud and 3 - 10D face nailing the joist to the stud, or use 16D and clinch the end of the 16D over with a big hammer. using a 1x keeps the notching depth down to less than the code limit of a depth not exceeding 25 percent of its width of the stud. 3.5" x 25% = allowed to notch 7/8"; 2x6, 5.5 x 25% = 1 3/8" (all for bearing walls; non bearing the limit is 40% depth.)

if you are using 2x6 studs you can ask the inspector if he will allow a 2x ledger; some will and some get a hissy fit because technically it does exceed what the code book says. best to ask.

grover
Member
# Posted: 11 Jun 2013 17:05
Reply 


I was not aware of the rule 25% limit in the code. Seems a 2x ledger in a 2 x 6 wall stud would still leave 4 full inches of wall stud remaining which one would think be enough. No inspections needed here but I don't want to do something questionable.

Redneck7
Member
# Posted: 23 Aug 2013 00:23
Reply 


Hey there, I hope it's not to late, but my advise is if you want to use 2x4's for 10' studs you can go 12" center and of a mid span block. That's what we do on load bearing 2x4 walls in 4 story apartment condos. Good luck on your build, hope you work it out.

Your reply
Bold Style  Italic Style  Underlined Style  Thumbnail Image Link  Large Image Link  URL Link           :) ;) :-( :confused: More smilies...

» Username  » Password 
Only registered users can post here. Please enter your login/password details before posting a message, or register here first.