Framing 20x30 1-1/2 Story with 2x4's

[cabinman]

I have just started to look at buying plans and building one of these great cabins. Since I will be covering the outside with at least an R-5 aluminum faced foam insulation, can I frame it with 2x4's to save on lumber and insulation?   

[MountainDon]

I believe the plans use a let in ledger for the upper floor joists to sit on.

Because of that 2x4 wall studs would not be advisable.

[rwanders]

I think you would find the price differential between 2x4 and 2x6 would represent a very small percentage of your total cost-----but 2x6 framing supports much better insulation installations and simply a better, stronger building. Especially in view of lumber quality nowadays.

[MountainDon]

20 x 30 = 100 lin. feet of walls. At 16"OC that would be approx 200 studs. We would also need bottom, top and upper plates to match, 100 feet worth x 3. If we use 10 foot studs the plates would be equal to 30 more studs. Toss in a few extras for cutting jack studs, etc.... let's say a total of 250 x 10 foot for the sake of figuring.

250 - 2x4 x 10 at HD here today = 250 * 2.98 = 745.00

250 - 2x6 x 10 at HD here today = 250 * 4.86 = 1215.00, only $470 more.

For the $470 you get stronger walls, deeper window sills (more useful in my book), more insulation (you can never have too much, today and tomorrow even more important)

Just my angle on it

and 2x4 with fibreglass and R5 foam has less R-value than 2x6 with fiberglass w/o foam. The foam does have the advantage of insulating over the studs which increases the walls overall R-value average. Either 2x4 or 2x6 would be better with wet blown cellulose in place of fiberglass batts though.

[John_M]

I will also add to Mountain Don's numbers that if you give Home Depot or Lowes or any lumber yard for that matter a materials list, they will try to outbid each other and compete for your business!!  That's even more savings for you!!! 

[rick91351]

Don't forget to try your local lumber yard as well.  If you give them a shot at a 'housing package' often times they will offer you a good discount.  Around here most will keep you on the computer or on file as a builder for a couple years anyway.  Very handy when you drop in for materials for the garden shed or patio cover on down the line.   

[rocking23nf]

wow when i check today in canada they are

2x4x10 - 2.18
2x6x10 - 3.55

and usually you get 10% off that price for using your home depot/rona card if you time it right.

oh and add 5% tax.

[MountainDon]

wow when i check today in canada they are

2x4x10 - 2.18
2x6x10 - 3.55

2.18 CDN ??  that's 2.08 US$
3.55 CDN = 3.38 US$

and the ones I buy here in NM often come from Canada

[davidj]

Plumbing walls are another issue.  I believe you can run 1.5" ABS through 2x6 load-bearing walls, and 2" ABS through plates (with metal straps) or doubled-up studs.  For load-bearing 2x4 DWV isn't gonna fit in the wall.

[davidj]

Another advantage I found with 2x6 was that the wood warped less.  It's pretty hot and dry in the Northern Sierras in Summer, and after a couple of weeks most unstrapped green 2x4s end up pretty bent or twisted.  With the 2x6's  it took them a fair bit longer to become crooked so it was easier to build a straighter wall.