Putting your new KK on your deck? You need help!

[billg71]

And I don't mean 4 or 5 of your buddies or a fork lift and a case of beer, you really, really need to get a structural engineer to evaluate whether your deck can support it safely.

It all boils down to gravity. You know, the force that keeps our feet on the ground and makes launching a satellite expensive. Your deck is designed to resist a reasonable amount of gravity, enough to keep you and your neighbors suspended above ground without crashing through it and being injured. IT IS NOT DESIGNED AND BUILT TO SUPPORT SEVERAL HUNDRED POUNDS OF WEIGHT IN A SMALL SPACE!  And if there's one thing a KK cooker is it's several hundred pounds of weight in a small space.

Deck design and how it's supported has varied over the years , we've all seen the news where the deck fell off the house and people got hurt. If your deck was built more that 15 years ago you're in the Wild Wild West era and I wouldn't put anything heavier than a lawn chair on it. Building codes began to address this and have increasingly mandated deck construction methods and design to the point that today any new house will have a deck that you can pack shoulder-to-shoulder at a party and have confidence you'll all survive the evening. But the codes don't address excessive loads like a KK weighing 500 lb. or more in a fixed location would be. That's where the structural engineer comes in.

I have to get a little techie here, we're talking about weight and the ability of a structure to keep it where you put it after all. Deck codes require a deck to support a minimum of 40 pounds/square foot of live load(think of a 160 lb. person packed into a 2'x2' square that follows them as they move around and fill your deck with those people). Big party, right? But everyone has a good time and gets to take their chances driving home.

Now let's look at what the deck is made of and the stuff that sits on it, that's called dead load. Codes require decks to support 10 pounds/square foot of dead load. That's enough for the deck materials and a reasonable amount of chairs, tables, etc.. What happens when you place a 23" KK on that deck? The footprint of a 23 is 23.5" x 30", now you've got 550 lb of weight concentrated in a space that 2-1/2 people would occupy for a short time. Less space than that since the casters are recessed. And the cooker isn't walking around, once you get it there it's there. Do some arithmetic: your deck which is designed to support 10 lb/sft of dead weight is now supporting 110 lb/sft. That's more than an order of magnitude greater than design. This is Not  A Good Thing.

Looking at the BB32 you're increasing the load to 118 lb/sft. There are no dimensions available for the SBB42 but I'd expect a greater increase, maybe somewhere around 130+ lb/sft.

OK, techie hat off: What it all boils down to is that it isn't safe to put any of these cookers on any deck that hasn't been engineered for the weight and location of the cooker. You might get lucky and just experience some sagging in the first few years but eventually there will be a structural failure(we all fall down). As I said, that's Not A Good Thing.

I've made my living building houses and decks for the last 25 years, never had one fall down. I use software to design beams, I work with suppliers on load calcs and I'm pretty good at what I do. I wouldn't put my 22" Supreme on my deck without an engineered design. "Do you feel lucky, punk?" I don't.

Please get some professional advice before you plunk that new KK in the middle of your deck.

FWIW,

Bill

[bosco]

my deck is concrete..... am I ok? just kidding.  Good post!

[ckreef]

Crap - if you have a wood framed deck, some amount of brain power, a few cinder blocks and a couple of 4x4's it's not too hard to shore up a deck for the weight of a KK. This really isn't rocket science. 

[billg71]

Charles I totally agree, it definitely ain't rocket science. But common sense isn't as common as it used to be and I'd have to say the average homeowner just assumes his deck will hold whatever he can fit on it. And he wouldn't know a 4x4 if you hit him with one. I've seen too many decks(and floors, and roofs) overloaded after the customer has moved in to think otherwise.

I may be a little cautious but liability insurance is a major expense for the business, if I don't absolutely know and have a code or calcs to demonstrate something I built will safely support something the customer wants then I have to refer them to a structural engineer. Knowing something will work and proving it in court are two very different things. And that goes for you as well: if your cinder blocks and 4x4s fail and your neighbor falls down and sues you, your HO insurance is going to throw you under the bus. It's sad that we've come to making decisions on who might sue us and how we're covered but it's where we are and we have to live with it.

I just want to make folks aware that you can't just haul one of these cookers up on the deck and expect it to stay there forever.

Best,

Bill

[ckreef]

I agree you @billg71 you just can't throw a KK up on a deck and think it's good to go. With that said a little common sense (if you have some) will go a long way. I sured up my porch with only a 16" and 19" just in case. With that said (again) send me a 42" my porch will hold without me worring about it. 

[Aussie Ora]

If common sense was that common we wouldn't have all these rules lol there has been alot of balcony (deck) collapses over the years from just to many people on them things are rated for a reason if you walk into a lift it clearly states the amount of kilos or people it can hold. There are to many factors in play here the substrate, is it Sandy, clay or rock. Is the area prone to movement. These things should of been addressed before the decks installation. But if the OP is unsure I would get it looked at nothing wrong with being safe when it's you and your family involved or anyone for that fact. I live on flat ground with pavers and a pergola so I'm sweet

Sent from my SM-P600 using Tapatalk

[cschaaf]

I wonder how many deck collapses came shortly after someone said, "Hand me those cinder blocks, I can make this work."  

[ckreef]

When I was in my teens a friends parents went out of town for the weekend. He threw a keg party and made the mistake of putting the keg on the deck. Parents came home to a collapsed deck. They were pissed. 

[tony b]

I've been on a deck that experience a structural problem. Fortunately only the center anchor bolt failed and the deck only dropped about 4" in the middle and didn't collapse completely. Good thing, as it was about 12 ft off the ground. It did scare the living crap out of all of us (about 30 people) on the deck at the time though. Didn't stop the drinking either! 

[MacKenzie]

Tony, that is an  experience that I'm sure you don't want to repeat.

[tony b]

It happened almost 30 years ago, but I still remember it well. And Yes, I don't want to experience that every again! 

[ZooBeeQ]

Our deck was built to support a hot tub but I move the KK around on a regular basis just to spread out the wear. It's only 3 feet off the ground but good point none the less. There have been a few deaths in this area because of this. Well mostly if you cant put more than 10 ppl in an elevator WTH would you put 20 on your 4th flr deck??

Not so common any more . :_) 

[Requis]

great thread, and as obvious as it might seem, this exact question came up when my carpenter asked me about my fancy new BBQ i was planning on buying.  Specifically he asked me how much it weighed to which I replied its heavy

We went on the site and looked it up and the carpenter is saying 8" centers for supporting joists on Trex composite decking.  The question I have for the original poster, if I am doing an out door kitchen island in a Wood subframe and Fusion stone rock facia to ( sorta)  build in the Big Bad.  Is 8" centers for the joists good enough?  Should I be going 6"?

And equally important will the trex composite decking be able to hold that weight?  Or should I do something different for the out door kitchen area that is being built on the deck.  I guess to highlight componants from a weight standpoint:

Weber Summit S660 gas grill

Marvel half height out door fridge

Big bad 32 Inch Komodo

Granite counter tops.

Which from all accounts is going to be alot of weight, and we have drilled in additional pilings for supports I'm just wondering if we should do 6" off center for joists.

Appreciate any help?

regards,

BJD

[Pequod]

8 hours ago, Requis said:

great thread, and as obvious as it might seem, this exact question came up when my carpenter asked me about my fancy new BBQ i was planning on buying.  Specifically he asked me how much it weighed to which I replied its heavy

We went on the site and looked it up and the carpenter is saying 8" centers for supporting joists on Trex composite decking.  The question I have for the original poster, if I am doing an out door kitchen island in a Wood subframe and Fusion stone rock facia to ( sorta)  build in the Big Bad.  Is 8" centers for the joists good enough?  Should I be going 6"?

And equally important will the trex composite decking be able to hold that weight?  Or should I do something different for the out door kitchen area that is being built on the deck.  I guess to highlight componants from a weight standpoint:

Weber Summit S660 gas grill

Marvel half height out door fridge

Big bad 32 Inch Komodo

Granite counter tops.

Which from all accounts is going to be alot of weight, and we have drilled in additional pilings for supports I'm just wondering if we should do 6" off center for joists.

Appreciate any help?

regards,

BJD

Just tagging @billg71 for you so he sees this. 

[tony b]

I have a deck made of Trex. One thing to consider, you have a charcoal grill, so if you ever get a stray lit coal - not good. I explicitly had my contractor put ironwood in the corner of my deck where the KK was going. It will scorch, but not burn. I have a couple of pock marks to show for it, too. 

[Bruce Pearson]

My daughter has trex deck and when it gets really hot it tends to bend easily. From my experience. I think 8" centers would be ok but maybe put a piece of 3/4 "plywood for the KK to stand on. Or better yet Tony's setup looks really good that iron wood is pretty tough stuff. The KK 32 weighs close to a1000 lbs. good luck and plenty pictures please

[billg71]

@Requis,

We don't use a lot of Trex here in N Georgia but I think 8" spacing would be OK for a KK and outdoor kitchen. Most of the load is carried on the joists anyway, as long as they're properly sized and supported you'll be OK. Personally, if I was going to spend what Trex costs for decking I'd just go ahead and spend the extra money for Ipe(pronounced Epay). I just did a quick search on pricing, Trex is running around $2.50/linear foot($5.45/sft) for the grooved stuff, Ipe is $3.83/lft($8.36/sft). So it's about half-again more expensive than Trex. BUT:

You can make arguments either way but Ipe is a renewable resource and responsibly grown and managed, it comes from a tree and trees consume CO2 and give off oxygen. Trex is made from sawdust, glue and assorted petrochemicals and it takes a lot of energy to make it, no oxygen is produced but lots of CO2 as a byproduct. Ipe can be sanded down and refinished, once Trex is worn it looks awful until it's scrapped and replaced. If you drop something like a hot coal on wood it'll scorch and can be sanded down and repaired, Trex will melt and burn(as @tony mentioned.

If you're getting the idea that I'm not exactly a fan of composite decking you're absolutely right. Drop by your local Home Despot and pick up a 16' piece of Trex and see for yourself how floppy it is. Then go pick up a piece of plain old PT Pine decking for comparison. Ipe is to PT Pine as PT Pine is to Trex. Now decide what you want to be walking on.

OMG, now I've gone off on my "Composite Decking Rant" again! My apologies, I'm a bit opinionated when it comes to wood butchery.

Honestly, I'd be more concerned with the weight from the stone and granite than the KK. Your Fusion stone weighs in at almost 15 lb/sft., granite countertops around the same. If you have a 3' tall cabinet faced with stone and a 24" granite top you're looking at 5x15=75 lb/sft, 7-1/2 times the usual dead load for a deck. My customers are inevitably amazed when I tell them what I have to do to their deck to keep their outdoor kitchen in the air but gravity is gravity and there's no going to court and appealing that law.

I've probably given you a lot more information(and opinion) than you wanted but these are all things you need to consider. It looks like your carpenter has a good grasp of the situation, work with him and you should be good to go.

Congrats on the new kitchen! Share some pics as it's progressing.

Best,

Bill

Edited May 5, 2017 by billg71

[Requis]

Thanks Bill!

really appreciate your perspective!  we did finally go with the trex decking as I'm not all that handy, and not interested in the maintenance work required to keep IPE looking its best.   ( adding my wife essentially said we're getting the trex as well and so that's an easy call,happy wife happy life lol) I figure if I can get 10'years of warrantynfree issues I'll be happy, I loved the tiger woods and IPE woods but the price here in Canada was almost the same, Tigerwood was actually more.

we also finally decided to build both out door kitchens and ordered the 22" table top unit with Dennis's awesome new table for the kitchen on the deck and are putting the big Bad down by the pool.  I know why two kitchens. In the summer we live by the pool and in the winter we don't go near the pool but still BBQ...andmhad another quick couple of questions:

1) my brothers wife (former welder) said I should just get a welders matt as they are cheaper and could span the BBQ area are comfortable to,stand on for hours on end and nothing burns through them....sounded like a great idea...but what do you guys think.. mat is $389.00 for 8 x 12

2)  my carpenter wants to use the black left over pavers from my drive way to finish off the kitchen area, says he can have the level the same as the trex deck and can use the trex to accent border the pavers in a seamless way that would look awesome.  He also wants to add 1k dollars for a 9 x 14 area to do the pavers cuts etc....

im leaning toward the welder mat...thoughts

thank you for any suggestions!

BJD

 

[billg71]

19 hours ago, Requis said:

im leaning toward the welder mat...thoughts

You just spent maybe $10K on cookers and a table and you're looking to save $600 and put them on a welder's mat? Really? Isn't that kind of like ordering your new AMG Mercedes with vinyl seats?

I dunno about leftover pavers, why not trot down to the local tile store and find something that would complement the KK and the teak? "In for a penny, in for a pound" and all that.

Seriously, you've just bought two of the best cookers in the world, real works of art. You've spent more money to make sure you have a safe place to put them, why not go the extra half-mile(or kilometer) to give them a home that complements their beauty?

See how little trouble I have spending your money? Just ask, I'll be glad to help.

Congrats on your new outdoor kitchens, I'm sure we'll enjoy them! And where are the pics?

Best,

Bill

Edited May 19, 2017 by billg71

[tony b]

Just a bit of feedback on Trex. It's not 100% maintenance free. Over the last few years, I have developed a lichen problem on it. Have tried various treatments to eliminate it, but most recommended chemical treatments are so harsh that they'll kill everything it contacts, so I've just learned to put up with some of it. YMMV.