Construction Details

knightfly · Post by **knightfly** » Sat Jun 07, 2003 10:50 am

Here is the first of some CAD details I hope to complete in this millenium - Tried to post this one at HR in answer to a Q there, but they only allow up to 64k, this one's about 96... Steve

knightfly · Post by **knightfly** » Sat Jun 07, 2003 10:56 am

Note that whichever way the sound tries to get in or out, there are ALWAYS TWO, and only TWO, centers of mass separated by ONE air space, in the way. (Thou shalt not use ONE, nor shall there be THREE, but only TWO - neither shall there be five... )

OK, no more blatant Monty Python ripoffs... Steve

Sen · Post by **Sen** » Sat Jun 07, 2003 11:42 am

Steve, thank you, thank you, thank........
You're a legend! Just what I needed and hope that many others will find it useful.
I just have one question:
Is there a certain amount of air gap between the frames you would recommend, or is it just purely up to you and space limitations?

Thanks so much Steve

Post by **John Sayers** » Sat Jun 07, 2003 3:33 pm

Cool Steve - your drafting looks great and I found it simple to follow.

May I question one thing. You are using staggered studs sitting on a 6" x 1" base plate. Why not use the normal double wall system and float the inner wall on the inner floor i.e. room within room. Also the joists would sit on bearers before the cement blocks.

cheers
john

Sen · Post by **Sen** » Sat Jun 07, 2003 4:16 pm

John, exactly my thoughts after having a second look at the drawing...instead of having the celotex between the inner wall and the floor to avoid hard contact between the two, why not just sit the inside wall frame on the floor....

...right??

Sen · Post by **Sen** » Sat Jun 07, 2003 5:20 pm

something like this I thought...???

Sen · Post by **Sen** » Sat Jun 07, 2003 5:22 pm

don't know why the stumps are not showing, but just imagine they're there

knightfly · Post by **knightfly** » Sun Jun 08, 2003 2:15 am

Guys, that was just a drawing I did for one of the guys at HR, who is building a shed on skids in his back yard for a rehearsal area. I figured if he moves it, the staggered stud approach would be stronger.

As I get more stuff drawn I'll post it - John, I agree there's better TL to be had with true double walls, floating everything, etc - that particular drawing isn't something I'm going to build, just an answer to one person's problems that I figured others might find useful.

It was also kind of an experiment to see how well my approach travelled over the net. I'm still drawing in Generic Cad, exporting to DXF, loading that into Autodesk's Quick Cad, then saving that as a JPG - I know it's convoluted, but it's still faster than learning a whole new proggie when mine is almost an extension of my frontal lobes by now.

I did have one person ask for larger text, he couldn't read it - hafta look into that one... Steve

Michael Jones · Post by **Michael Jones** » Sun Jun 08, 2003 4:37 am

I built my exterior walls very similar to your drawing. I don't know if it would be a good idea to use a wider base plate, of course, it HAS to be pressure treated. Pressure treated lumber is VERY heavy! You also have to put some kind of base plate seal between the foundation and the bottom of the pressure treated base plate. It comes in rolls, and its kind of a neoprene/cellular stuff. I have NOT seen it come in rolls wider than 6".
Something else to think about is that door frames, for external doors are not going to come wider than 6". And even to get THOSE, its a special order. So a wider base plate means you're looking at some really funky trim out or a custom built door frame. $$$$
CHA-CHING!
Also consider the fact, that your door headers are going to have to be "Glue Lam's." To construct these, you use (3) 2x8's and sandwich (2) 1/2" strips of 8" wide plywood between them. That gives you a total width of 5 1/2", the width of your base plate. Use a wider base plate, and you're looking at a heavier door header too, depending on the span of your door, that may or may not be a good thing. (It can actually get too heavy that its not supporting the "criple studs" above it properly.)

I built my walls in basically 10' sections with a 2x6 base plate, 10' staggered studs on 16" centers front and back, and a 2x6 top plate. It took 3 people to lift it up and position it over the foundation tie downs, and that was with NO exterior sheathing on it. To brace it or rack it square, I just used lumber on the outside set across it diagonally.

The point here being is that the beefier you make the framing, the heavier its going to be. Naturally.
Just keep in mind that you'll actually have to erect this thing, and don't get yourself into a position that you'll have to employ a crane to tilt up your walls!

This is kind of off-topic, but another thing that continually amazes me is how each stage of construction adds to the rigidity of the structure.

You start off with a frame section on the ground, and its racked for square, but its still kind of "wobbly".
Then you get it tilted up and braced to plumb, that secures it, but you find yourself hoping there's no high winds!

You finish the perimeter and get them all nailed together, and that helps, but they still move some.

Then you place the top cap, which overlap the corners and all seams, and you feel like "Wow! That really helped. It doesn't move QUITE as much.

Then the roof trusses go up which kind of pins the top, and you start thinking, "Alright! Those babies aren't going anywhere!"

The first layer of external sheathing goes on, and you finally have a pretty rigid structure, allowing you, for the first time to begin removing the temporary bracing.

As the internal framing goes up, it finally begins to feel like the rigid structure its supposed to be.

And finally, as the internal sheathing is placed, you get the feel for how massive and sturdy your structure really is!

knightfly · Post by **knightfly** » Mon Jun 09, 2003 1:38 am

Michael, I know what you mean - it's hard to believe at some of the intermediate stages that it would take more than a knat's fart to blow the whole thing down -

As I mentioned earlier, that particular drawing was done for one of the guys at HR, not for me. I'm planning on ICF constructed outer walls with 6" concrete and 2-3/4" foam each side, then couple layers of wallboard inside that, probably 6" air space then 6" steel studs/2 more layers of wallboard, etc - all inner walls will be steel stud and drywall, except where specific wall treatments don't work as well - that should keep things light enough to be doable.

If I really needed a crane, I might be able to use my backhoe - except that my walls will be 16' high, and the middle joint on my hoe sits about 12' off the ground...

Anyway, here's the next installment for the HR guys, hopefully they are easier to read... Steve

knightfly · Post by **knightfly** » Mon Jun 09, 2003 1:42 am

And, a close-up of the same, showing caulking locations...

Post by **John Sayers** » Mon Jun 09, 2003 10:27 am

Those drawings relate well Steve - even if it's long and convoluted way of getting them

:)

What I can't understand is why use resilient channel when you are building a staggered stud wall (which achieves the same) ?? It's sortta double wammy!!

cheers
john

knightfly · Post by **knightfly** » Tue Jun 10, 2003 10:52 am

"What I can't understand is why use resilient channel when you are building a staggered stud wall " -

John, you could leave out the RC but from what I've read, staggered stud construction by itself, while better than straight stud walls, could still be helped with RC on one side, considering that the top and bottom plates/caps are common to both sides of the wall, and that wood studs are stiffer and will de-couple less than the thin steel ones (for non-load bearing walls)

I was under the impression that using steel studs negated the need for RC as well, til I saw examples in the USG handbooks of using RC to improve steel stud drywall construction by 2-3 dB. (I'm not sure, but that MAY have been a load-bearing wall using 6" heavier steel studs, whose extra stiffness would benefit from use of RC for extra decoupling)

The things that seem to make the most difference in TL (assuming a double-leaf wall) are mass, de-coupling, air gap, and dis-similarity of inner/outer mass, not necessarily in that order. (Oh, and distance from the source-of-course - inverse square law, an' all that... :=)

To top off the "moot point" scale (in a way) the person at HR that I originally drew this stuff for, is having "sticker shock" and may not build that way after all. Still, I think having a complete set of drawings for different types of construction is a worthwile project so I'll keep working on drawings with explanations, posting when I'm happy with each set.

If anyone is in need of a PARTICULAR detail, feel free to ask - I'm not close enough to ground breaking yet that it matters what I draw next... Steve

Sen · Post by **Sen** » Tue Jun 10, 2003 7:36 pm

knightfly wrote: If anyone is in need of a PARTICULAR detail, feel free to ask - Steve

I will...again...sorry

As I said before, I've no great knowledge about building framed walls, so my question is: Do the wall plates have to be common for both frames (inner+outer) when building staggered stud walls, and is there anything similar to dead men invovled when not using brick?? Do you have to tie the frames togehter?
I know these are probably dumb ?s, but I'm not sure, so I'm asking

Also, what's better when putting insulation itno the floor:
-Insulation touching the floor or
-An air gap between the two as shown in the drawings above?

thank you all very much

Michael Jones · Post by **Michael Jones** » Wed Jun 11, 2003 2:02 am

oops!