[GravityAlwaysWins]

Looking for advice on spreading a point load effectively & thickness of plate needed.

Where: 2nd floor back deck made of Trex
What: stainless steel grill table, 34"x62", with a ceramic grill, ~1000 lb total with extra charcoal, equipment, etc. (first pic)
Table support: mostly 4 casters ~2"x0.5" contact patches. There are 4 feet you can lower to prevent rolling, so they can bear some add'l weight. Very similar to second pic, but our casters are wider.

We worry about the ability of the Trex to not deform under these point loads. So we wanted plates underneath that are thick enough to spread the load. We were thinking ~4" wide, front to back, on each side. But we don't know what thickness we need.

Is 1/8" thick stainless enough to _spread_ a ~300lb point load (grill isn't centered so weight isn't), or would it just transfer it through?

[BlackTalon]

I personally would be more concerned about a 300 lb point load on a single trex board, depending on where that load is located with respect to the joists. It's been a couple of years since I tried to get material properties for trex to perform a structural analysis,m but back then they did not make the properties available.

I suggest keeping it simple, and setting a piece of trex under each wheels/ casters combo that is long enough to spread to two widths of trex boards.

These materials tend to creep/ deform over time under a constant load, so load issues may not be apparent for quite a while.

[Vicegrip]

2 lengths of stainless steel C channel that span the wheel base side to side. Center of the channel wide enough for the caster to fit in. Place the channels and roll the grill into them. The channel is more ridged than same thickness flat stock and you spread the load across many boards and perhaps a joist or two as well.

[GravityAlwaysWins]

Originally Posted by Vicegrip

2 lengths of stainless steel C channel that span the wheel base side to side. Center of the channel wide enough for the caster to fit in. Place the channels and roll the grill into them. The channel is more ridged than same thickness flat stock and you spread the load across many boards and perhaps a joist or two as well.

That's very similar to what we have already, but wanted the grown up version of. Right now, it's on 2 sheetmetal channels that I think are toekicks from the garage cabinets. They go front to back b/c it was easier to move that way given deck layout. Sliding into place using the channel as guide was awesome. Only the current channels are SUCH thin metal.

We hadn't thought about the channels having extra rigidity. Thank you! We did spent a LONG time trying to find channels online because we liked the guide function. Finally decided we'd have to buy flat stock and find a place with a press willing to bend for us. Is that easy to find?

[N0tt0N]

If you invite enough people over for barbeque a load will be evenly spread across the deck.

[BlackTalon]

Originally Posted by GravityAlwaysWins

We hadn't thought about the channels having extra rigidity. Thank you! We did spent a LONG time trying to find channels online because we liked the guide function. Finally decided we'd have to buy flat stock and find a place with a press willing to bend for us. Is that easy to find?

Search Bluebook.com for metal/ steel fabricators. A local place would probably bend something up for not much $, and may also have scrap stock so the material may not be too $$. Barring that, you can check places like mcmastercarr.com, altough expect to pay $$ due to shipping costs (and because SS shapes in general are expensive)

[smdubovsky]

Aluminum channel of any appreciable thickness will spread the load well too and will be over an order of magnitude cheaper than stainless.
http://www.onlinemetals.com/merchant...p=2&top_cat=60

[Vicegrip]

^True and easy to find in a wide variety of dimensions. Aluminum has a propensity to make hard to remove black AlOx stains when in the presence of tannin acids from leaves and other organics.
Taking the pictured location with background trees, deck build and not cheap inexpensive grill into consideration led me to recommending stainless. 18 or 20 gauge SS would be plenty stiff enough and still easy to roll into and out of as the grill is moved for cleaning or otherwise.

Dixie Sheet metal in Falls church can cut and bend up any shape you like if it is not available online.

Four 4X4 or 6X6 ceramic floor tiles from Home Depot would work too and around $.79 each be far less expensive but arguably a bit more a pain in the ass than any of the above.

[roundel]

McMaster Carr is awesome.

https://www.mcmaster.com/#standard-s...nnels/=16rtdp5

I would expect my order within 48 hours with cheap shipping.

[GravityAlwaysWins]

Thanks for the suggestions, folks. This will definitely get us further along in our project. Somehow we didn't find the u-channels online, Roundel, yet there they be.