It's not clear why a bidder would be allowed to substitute a different wall system and why that bid would become part of the contract. What kind of contract did you sign? Are the wall substitutions listed in the contract form or the drawings and specifications modified by addendum and listed in the contract?

In a stipulated sum contract the contractor is obligated to build what is described in the contract documents regardless of the bids he has received but a cost of the work contract might allow substitutions in the buy-out process with the owner's written consent.

It would help to know if all the framing, drywall, and wiring is installed; the height of the walls and if any are load-bearing or fire rated.

The required bracing in a metal stud wall is parallel to the face of the wall and 1/2" drywall is usually adequate to meet that bracing requirement assuming the wall is not load-bearing. If the wall is unusually tall, additional studs can be sistered to the existing ones if the walls are still open. An additional layer of 1/2" drywall can be added to one side to make the acoustical quality of the wall possibly even better than the original double 5/8" design.

I'm curious to know why you are using steel studs in a home. They are normally used in building required to be of non-combustible materials.

I have been involved as the architect of record in far too many of these situation and feel I should point out that your consultants could have been more professional in their response by not making vague off the cuff statements about bracing that appears to have made a difficult situation more difficult for everyone and unnecessarily stressful for the owner.

There is always a solution and all the parties need to cooperate dispassionately in order to find it quickly. I learned a long time ago that it is best to discuss a problem with the builder without the owner present and to then present the problem with its possible solution(s) to the owner.

macv- thanks for responding. I hoped you would read this post.

Our contract w/ the GC was to build per the architect's plans. Since we are paying him cost$ + 15% there is no incentive for him to scrimp. We have not requested a modification for inferior materials or methods. He has not suggested a modification of materials or methods. His job is to get a sub to properly quote per the plans, make sure the sub does things right, collect $ from us, and pay the subs.

There are no bearing walls. There are 4*6 solid steel supports along an off-centered line that holds the steel beam that supports the engineered truss roofing system.

I think steel studs were preferred because of the height of the walls, and our climate (coastal Florida).

The walls are open. Spacing is 16" on center, 11' wall heights, with one room (foyer) that has a groined ceiling peaking a 15'.

Electrical wiring has not been run- but outlet boxes are installed.

I hear what you are saying about how the communications were handled. In this case the builder referred us to the architect, so I assume the architect does not want to ruin a referral source. We paid a handsome fee to the architect, so I think he owes us an honest report that the framing was not done to the contract spec that he wrote. They need to work this out WITH US, not behind our backs. I am installing about 120' of 50" upper cabinets, cladding 400 sq ft of wall with 5/8" marble, hanging 6 big TVS, and other misc heavy objects. This is a very expensive build. I deserve to feel confident that the walls will properly support the interior build out, and that the construction methods are consistent with the quality home we designed.

You can exceed the the original design resistance to lateral force (perpendicular to the wall) by applying two layers of 5/8" GWB to each side of the studs assuming they are not load bearing. Two layers of 1/2" GWB each side would be substantially better then the current construction and might be easier to implement. If you are supporting heavy objects on a wall, the same amount of extra blocking should have to be installed whatever the design of the walls. If the loads exceed the axial strength of the 25 ga. studs (unlikely) ask that they be doubled at those locations. In fact, doubling the studs everywhere (or at long unbraced walls) and using 5/8" GWB is another possible solution.

I would ask for the additional drywall to get the additional sound separation but be careful, you will be paying for the additional cost of the work unless you can prove that the original design would nave been cheaper which could be a can of worms.

mavc- I just checked this thread and found that my "THANK YOU SO MUCH" message that I posted earlier has either disappeared or I forgot to hit "post." As I had said, you are truly very kind to have given this matter your attention. Not only did you propose a solution, you have made me feel better. I did not think anything could make me feel better today!
Pamela

I'm impressed that a homeowner is actually listening to sensible advice. Mistakes happen. This one was caught early and there are clearly solutions that may get you a better end product than you bargained for.

If you get the additional drywall, be sure the kitchen cabinet makers know. I once had a kitchen delivered that was one inch wider than the wall it was to be on because the cabinet company measured the walls before drywall was installed and forgot to account for the extra inch. The installer spent two days on-site just narrowing the cabinets.

Thanks for the head's up on the cab measurements Worthy!

Re mistakes- yes, we all make them, and you are right- this one was caught in time to make a difference.

I think I went ballistic yesterday because I have not been totally comfortable with the steel stud idea from the beginning. This will be my first no-load-bearing walls house, and I am hanging so much weight on the walls. It's kind of scary.

Reading the contractor proposals/proffered contract carefully is mandatory. My HVAC contractor listened, so I thought, to the features I wanted my system to have. His contract listed model numbers of equipment, looked like well-done contract. I signed, he installed. That equipment did not have the features I wanted and for the most part, could not be retrofitted. I got what the contract specified, but not what I wanted. Verify, verify, verify.

Interior steels studs are commonly 20 or 25 ga. and the need for the heavier stud is usually determined by the height of the wall and 11 ft is starting to get tall. As I mentioned earlier adding drywall can reduce the potential deflection of the stud perpendicular to the wall plane since the drywall acts in composite fashion with the studs.

25 ga. steel studs should be are sufficiently strong to support whatever you might want to hang on them (as long as they don't project too far from the wall) but what has to be taken into consideration is that, unlike wood studs, steel studs tend to twist. After the drywall is installed twisting is no longer an issue but keeping them in position during drywall installation is more difficult with the lighter taller studs. To keep them in place the installer can use "spacer/bridging bars" that are steel channels force fitted into the cut-out holes in the studs stabilizing them and keeping them at the correct spacing. This is probably the additional "bracing" that your consultants mentioned would be required. It's not a big deal to add more of it.
Similar bracing over the door openings would be needed in any case as would "backing/blocking" behind cabinets, etc. (see next post).

Here is a link that might be useful: spacer/bridging bars

Blocking/backing at cabinets, etc. can be continuous thin metal straps over the face of the studs, solid 2x4 blocking between the studs or prefabricated plywood backing units between the studs. The strapping is fast to install, the solid blocking is strong, and the plywood backing units combine both features. If you are concerned about strength you might prefer the plywood backing units.

Here is a link that might be useful: prefab plywood blocking/backing

Macv, great line about "There is always a solution and all the parties need to cooperate dispassionately in order to find it quickly."

No finger pointing, just brainstorming on how to make things right, even if that might not be what was in the contract or what was "understood" by some of the parties. I think your view on these situations is the real value a good architect brings to a project, and you (and worthy) seem to bring that value to this forum.

Let it be a lesson to OB'ers too, at some point, something will be done wrong (in your view, maybe not the contractor's view). If you show emotion, or throw blame, you will probably have a tougher time getting the problem fixed than if you calmly talk about how to fix the problem and what you want the end result to look like.

Resolution reached. Builder is sistering 20 guage studs onto all the 25's, he is paying for the studs and install, we are paying for the upgrade to 5/8" GWB from the 1/2" that was quoted.

Macv- I have started making my schedule of 3/4 plywood reinforced areas. The prefab product that you linked to looks good. I will ask the builder to use it if he can get it locally.

2 x 4 blocking has already been done in some areas. I am working on the full schedule of where we want it.

Am I naive enough to think he won't take some the stud cost out of my hide along the way? No.

I'm sure I've mention this before but I learned how to keep a project moving from a super who had retired from the Army as a First Sergeant - the perfect training for a problem solver. But he refused to allow the word "problem" to be used by anyone and called any disruption in the work an "opportunity" and he meant it.

Being surprised when a project has a disruption is like being surprised when it rains. As they say at sea, he was a good man in a storm.

That is certainly a far stronger wall then was originally designed. Even sistering 25 ga studs would be stronger since spacing is more effective than steel thickness. This is like studs at 8" o.c.

What your builder is hoping right now is that his mistake might cause everyone to monitor the work more carefully from now on. Keeping him on his toes will pay off in the long run.

This thread should be mandatory read for anyone heading into a build.

Your problem solving skills will be tested at every turn. Dispassionate is a very apt word to describe the ideal mindset.