Metal Studs?

rocktavian · Post by **rocktavian** » Sat Aug 27, 2005 11:48 pm

Is there any reason why i couldnt use metal studs to build my project? I know they will probably cost more but with my slow ass building skills i wouldnt have to worry about wood rotting before i could get a roof on it.

knightfly · Post by **knightfly** » Sun Aug 28, 2005 3:10 am

http://www.buildingscience.com/resource ... ldings.pdf

Read carefully the section on Moisture Balance, but read the entire document a few times til you completely understand what Joe is saying;

Bottom line is, I don't recommend steel/gypsum construction in a highly insulated, sound proof studio UNLESS you have enough space to dedicate at least a FOOT of open air space between inner and outer wall frames, and a way to ventilate that space to inner, dehumidified and conditioned space when not using the studio. My own planned facility will have at least two FEET between inner and outer wall leaves, with full air circulation between them and dehumidification in addition to the HVAC system.

If you use steel framing, you need to spray any cuts with zinc chromate primer before assembly. You also need to make sure all connections between concrete and steel stud frames have a thermal break - 2 layers of 30# building felt works, as do a few specifically intended products. You do NOT want the moisture in concrete (read the linked PDF about that) to be in contact with your steel framing. The more insulation (decent sound isolation) the more this is true.

Have you posted plans for your construction anywhere yet, or is it not to that stage yet? Generalities can only take us so far, then it's time for specific details.

IF you're planning a free-standing or add-on space, you might want to consider dry-stack block walls - easy for one person, stronger than mortared block, and (filled with sand) VERY good outer mass leaf. \

http://www.thenaturalhome.com/drystackblock.htm

http://www.new-technologies.org/ECT/Civil/psk.htm

Some things to think about... Steve

rocktavian · Post by **rocktavian** » Sun Aug 28, 2005 5:32 am

Thanks,
I was just wondering about other options. I have the thread "studio Layout help" going but i was just looking for options. Metal seemed to be less weight and easier for one man to mess with as well as not having termites and other critters to deal with.

knightfly · Post by **knightfly** » Sun Aug 28, 2005 5:42 am

Right, and steel also has the advantage of "no knots" - I'm not saying it shouldn't be used, only pointing out some things to be careful of that could otherwise spoil your fun... Steve

rocktavian · Post by **rocktavian** » Sun Aug 28, 2005 5:48 am

that block thing looks kinda cool too.

knightfly · Post by **knightfly** » Sun Aug 28, 2005 6:11 am

Yeah; it's strong, it's masonry, it's massive, it's doable without help (if you know how to build a footing), and it's relatively fast (no mortar except for bedding the bottom course of blocks) - and the surface bonding cement adds to mass for better TL than mortared block, even when both are filled... Steve

rocktavian · Post by **rocktavian** » Sun Aug 28, 2005 7:30 am

my problem is i already have a slab poured.

knightfly · Post by **knightfly** » Sun Aug 28, 2005 10:59 am

Might not be a problem - what dimensions are the perimeter footings, rebar, steel, etc? It's possible your existing pour might be strong enough already... Steve

rocktavian · Post by **rocktavian** » Sun Aug 28, 2005 3:23 pm

My slab is 18 x 24. i believe the footing is a foot deep and loaded with rebar and mesh. i have no doubt it is strong.

knightfly · Post by **knightfly** » Wed Aug 31, 2005 2:34 am

I finally found time to check your other thread; I think that, if you DIY and get help from friends you CAN enclose the space within your budget; but a couple of points -

One, if you build NORMAL wall construction (stud frame, some kind of outer siding) it will NOT be easy to upgrade that outer leaf of mass when you get more $$ for the inside construction - so if possible, I would add at least one more layer of heavy plywood on your outer stud frame before hanging siding on it - that way, you'll have a fairly hefty outer mass in place.

Two, you need to think in terms of two separate mass envelopes, as isolated from each other as possible, for best sound control. So the outer envelope will need to be one continuous un-broken high mass surface, including the roof or ceiling; if you do a vented roof, then you need to make the "box" tall enough so you will have room for an inner frame and ceiling material IN ADDITION TO the outer leaf - see the illustration below for what I mean.

As to what to use to get this "mass envelope", your timing sucks nearly as much as mine

- Thanks to the lovely "KATRINA", heavy plywood (like the 3/4" you'd need under your outer siding) will probably double in price in the next couple weeks (again) - for that reason, I'd not dismiss the (DRY sand filled) concrete block outer mass without first comparing material costs.

One problem with the dry-stack method though - standard blocks are NOT 16" long, they're 15 5/8" long to allow for a 3/8" mortar joint - so dry stacking makes them come out uneven compared to standard building sizes, except in wall lengths of 13 feet (13.02 feet actual) 26 feet (26.04 feet actual) and 30 feet (29.95 feet actual) - in the case of your 18 x 24 foot slab, you would need to use partial blocks somewhere in each wall in order for your footings to be directly under the mass of the wall (assuming your footings are even strong enough for the weight - this type wall would weigh about 940 pounds per lineal foot (assuming 10 foot tall and sand-filled)

Considering your (very) tight budget I think I'd go for a single stud frame with 2x6 studs on 24" centers, and sheath the outside first with 3/4" OSB, Tyvek and siding - this would give decent outer mass.If you go with 12' tall walls and a gable roof, you can vent the roof thoroughly and use double 5/8 gypsum on the bottoms of your roof trusses for a continuation of your walls' outer mass - then there would be room for an inner frame later for the inner ceiling and inner wall mass.

Doing it this way would allow for a "pay as you go" approach that won't be "half-fast" when done, and still let you get the place weatherproof NOW... Steve

rocktavian · Post by **rocktavian** » Wed Aug 31, 2005 12:56 pm

knightfly wrote:
Considering your (very) tight budget I think I'd go for a single stud frame with 2x6 studs on 24" centers, and sheath the outside first with 3/4" OSB, Tyvek and siding - this would give decent outer mass.

I am a little lost on the 2x6 studs. I was thinking of 2x6 top and bottom plate and then staggered 2x4 studs, thus allowing some separation between the inner and outer walls. I was also thinking of using 8x4 hardiboard as siding. that stuff is just super tough and paintable as well.

I think the Katrina thing will probably slow my building down till the first of the year. Most of there evacuees are here and i expect since we sent just about every utility worker we have in there direction; then more than likely there building materials will come from our local Papermills, steel mills, lumber companies, etc.... I am in no major rush. I wanna do it but i am a tightwad with money so i can wait till the prices come back down.

Who knows maybe by the 1st of the year i can save enough money to just do it all . If i stay on this board i may even be smart enough to do it right.

thanks for the help.

knightfly · Post by **knightfly** » Sat Sep 03, 2005 2:29 pm

I am a little lost on the 2x6 studs. I was thinking of 2x6 top and bottom plate and then staggered 2x4 studs

That is one way you can do it; I don't know just how much isolation you will need, so my suggestion was part of a plan to do full 2x6 stud frames for your outer wall, then when "phase 2" happens do a second, isolated frame inside that and use 2 or 3 layers of 5/8 gypsum wallboard - the fully separate inner frame will improve TL by about 4 dB at low end, and about 10 dB at midrange. It's actually cheaper to frame entirely with 2x6 on 24" centers than to frame with staggered 2x4's, since they need to be twice as close together and 2x4's cost more than half what 2x6's cost.

The Hardiboard thing - if you're talking about their LAP siding, bad idea. Each joint is a major leak area, as well as a thin spot in the mass envelope... Steve

rocktavian · Post by **rocktavian** » Sat Sep 03, 2005 10:33 pm

i was talking about the 8x4 sheets of hardiboard like plywood but concrete.

Post by **sharward** » Sun Sep 04, 2005 1:16 am

Steve, a bit of Googling tells me that HardiBoard is a competitive product to WonderBoard (by Custom Building Products) and Durock (by USG Corporation).

I'm nnot sure who makes it, or even that the spelling is correct, so I can't find a data sheet for it.

rocktavian · Post by **rocktavian** » Sun Sep 04, 2005 1:57 am

it is basically hardi plank siding but it is in sheets of 8x4 instead of strips. that durock looks very similar