# Galvanized Studs for Outdoor Kitchen



## AikiPapi (Jul 28, 2010)

Hi, All.

Continuing to enjoy reading in this forum and learning a lot along the way.

Quick question about which type of galvanized stel studs to use in framing an outdoor kitchen (in NJ). I'm not quite a DIY guy yet so I have a contractor doing most of this, but I've certainly learned a lot of the right questions to ask here.

I notice that he's using G40 galvanized studs (25 gauge, I think) where typically the higher levels of galvanization (G60 and up) seem recomended for exterior walls in general construction. Is this something I should be concerned about?

Thank in advance for any insights!


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## Bud Cline (Mar 12, 2006)

The G40 will likely out live us all. But, what are the studs being covered with? If cement board is being used the gauge should be about 18. Twenty-five gauge won't always take a screw if it is in cement board without stripping out the stud and leaving the screw head standing proud.


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## AikiPapi (Jul 28, 2010)

Thanks for the reassurance, Bud. That frees my mind up to obsess on other details of the build (follow-up posts coming soon to a chatroom board near you!).


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## concretemasonry (Oct 10, 2006)

You will always have to confront the classic problem of corrosion to the studs when a self tapping screw or drilled thing penetrates a steel stud (creating a moisture path to the steel stud by cutting into the galvanizing) while in a moist environment. - I have seen this many times on commercial buildings where moisture gets into the area behind the exterior finish.


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## AikiPapi (Jul 28, 2010)

Sounds like I'm probably going to be dealing with the same primary issue at the points of penetration regardless of the level of galvanization. I suppose I can live with that better than knowing I've made a key structural mistake.

Hope I understood you correctly - and thank you!


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## Bud Cline (Mar 12, 2006)

> You will always have to confront the classic problem of corrosion to the studs when a self tapping screw or drilled thing penetrates a steel stud (creating a moisture path to the steel stud by cutting into the galvanizing) while in a moist environment. - I have seen this many times on commercial buildings where moisture gets into the area behind the exterior finish.


Very true - good point. 

You could always waterproof the wall to mitigate moisture migration into the structure.

You didn't answer my question about how the wall was to be prepared beyond the studs. Would be nice to know.


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## AikiPapi (Jul 28, 2010)

Oops - sorry. Cement board (Hardibacker) is being installed over the galvanized frame. I honestly don't remember the gauge of the studs so I could be off with that but it does look to be going well from that standpoint. I'm just trying to figure out what's reasonable to question up front as opposed to dealing with avoidable consequences a few years from now. Access to the inside of the island seems pretty good so I suppose my best bet to defend against rust & corrosion might simply be to inspect the inner frame annually and keep a rust protectant spray handy.

Still trying to find that balance between due dilligence and driving our contractor off the job!


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## AikiPapi (Jul 28, 2010)

I was also a bit concerned about the studs that were in direct contact with the stone patio (those that aren't shimmed) and the corrosion and rust that might ensue. The patio does drain well so I don't foresee them actually sitting in water too often and from what I understand there would need to be another metal and an electrolyte (water?) involved to spawn true galvanic corrosion. Trying to talk myself out of sweating this detail I suppose.


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## Bud Cline (Mar 12, 2006)

I think you are over-analyzing the benefits of the galvanized studs. The studs will be fine, it is the cut edges of the metal studs and the fastener penetrations that will rust and corrode first. The stud construction could be built on a redwood (or treated) bottom plate to protect any oxidation from staining the stone.

You should investigate the use of Hardibacker. Hardibacker (tile-backer panels) ARE NOT rated for outdoor use. Don't know why because Hardi also produces a great siding material that is. I am told that the formulas are different even tho the products appear to be the same.

The walls could also be waterproofed with a liquid waterproofing material. Laticrete's Product 9235 qualifies for this. There are others but they all may not be rated for exterior use. Bed and tape the seams using ceramic tile thinset and alkali-resistant tape, then waterproof the seams and the entire board surface as well. Sorta like building a tile shower.


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## AikiPapi (Jul 28, 2010)

Thanks again, Bud. I'll try to shift my attention to some more practical concerns (like fasteners, etc.) as you suggest.


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## chuckyd (Dec 3, 2015)

According to various galvanizing organizations in the USA, G40 galvanizing will outlive only those who will die within the next 20 years.


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## danpik (Sep 11, 2011)

Well then it looks like his kitchen will only last another 15 years. Original post was from 2010


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## AKJammer (Apr 20, 2017)

It'd be nice to know how it's got along since it's been 7 years now.

Any updates? 

I'm looking at building my own outdoor kitchen using the 25Guage studs at Home Depot. I'll put some composite decking underneath to keep it off my pavers, then concrete backerboard over top the studs. Finish it with some stacked stone tiling. Not sure what I want for countertop yet. Would like to use concrete, but I'm not building on a pad, just the pavers, so don't know about long term stability/settling. (No, I'm not going to pull up my pavers, thank you very much)


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## Noel256 (May 31, 2018)

AKJammer said:


> It'd be nice to know how it's got along since it's been 7 years now.
> 
> Any updates?
> 
> I'm looking at building my own outdoor kitchen using the 25Guage studs at Home Depot. I'll put some composite decking underneath to keep it off my pavers, then concrete backerboard over top the studs. Finish it with some stacked stone tiling. Not sure what I want for countertop yet. Would like to use concrete, but I'm not building on a pad, just the pavers, so don't know about long term stability/settling. (No, I'm not going to pull up my pavers, thank you very much)


I used the 25 gauge studs at HD to build my outdoor bbq kitchen in South Florida. My backyard floods when it rains a lot but it eventually drains after several hours. The bbq island sits in water when this happens and so far I haven't noticed any rust. I built it in January 2017. I used Durock for the walls covered with brick veneer and metal mesh on the back side with stucco. It sits on top of pavers and is not anchored down. It has a 1.5 inch poured in place countertop. It made it through hurricane Irma and did not move or sink. The pavers I laid myself with 4 inches of crushed stones and 2 inch sand bed which I leveled and let it sit for a week, it got rock hard after rains then I put the pavers on top. 
I did screw Durock to the underneath of the studs so essentially the entire island is sitting on 1/2 inch durock which sits on the pavers. Now that I think of it, it would have been better on composite because eventually the durock might crumble. Well so far after a year everything looks fine, will see after 5 years! At least now I know how to build them!

Noel


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## Patiobob (Aug 12, 2018)

We now build 4-6 outdoor kitchen islands each year. We just finished a 42' rooftop island on beachfront property this spring. Years ago, my very first island was started out of home improvement store galvanized studs. 6 hours later I realized it was going to be an absolute piece of garbage and I tossed it. I researched both thicker studs and different methods. We now use square or rectangular tubing for all of our islands. Three coats of paint for the metal or we use aluminum for shore applications. We don't even need footing as our units are structurally connected from bottom to top. If you were to sit the unit down on an uneven surface, it would not twist. We often bring them in complete with an excavator and swing them into place after building them in the shop. Then we install the countertops. I know not everyone can weld, but I've done my fair share of "repairing" galvanized stud kitchens. Lots of disadvantages with them, for one, they generally cannot be moved ever again once installed. More important though, is that if the base is not done properly, and the unit sinks/twists, the countertop will often crack. I have seen many with rust through spots. It is not to say the entire unit rusted out, but that a key piece rusted, usually next to the grill where water can get in, and then the unit failed, twisted, or bent and took the facing or countertop with it. Most people don't realize that you remove the galvanization when you cut or screw those studs together....and you absolutely have to scrape the galvanization off to weld those studs, as the fumes are toxic.


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