Gas burner on concrete floor

[Danny]

So I have a 3 ring gas burner (the green type, fairly standard i think) - I have been using it straight on the garage concrete floor with my 50l pot straight on the burner, no stand. no bricks etc.

I think I've done too much reading and have heard about concrete exploding if it gets too hot.

Is this a real concern or is there not enough heat coming off the bottom to worry about??

Is building some sort of stand a wise idea, and if so, any design ideas??

[Dunc]

I'd put some bricks down dude. There's a fair amount of heat reflected off the base of your pot so make sure there's an air gap underneath the burner. I haven't heard of exploding concrete but it would really ruin a brew day.

[Hamish Jones]

I have seen concrete explode when someone at a party decided to start a small bonfire directly on it, it took a while but it went off with a hell of a bang and made a big mess with seriously hot concrete shrapnel flying,

[Dunc]

OK I've heard of concrete exploding now. Jeeesus.

[Danny]

Something to do with air bubbles in the concrete expanding as they heat i think

[Tilt]

Just found this thread and photos showing the effects of a kick arse burner and reg set up on a concrete floor. 

Makes those fired bricks or a heat shield seem like a good idea.  Brew safe brothers and sisters.

[Tilt]

Plain house bricks are good but there are other options too. 

I didn't want any height or weight added to my wooden brewing benchtop so I use a small sheet of refractory fibreboard (the type they line chimneys with).  It works a treat and there's no charring on my benchtop. 

Contact a local fireplace/burner installer and they might have some offcuts.

[Paul Fraser]

I do just the same ( 3 ring with 50L pot) and never had a problem. Done 2 hour boils no worries. I didn't know concrete could explode.

[Tilt]

Just to add some thoughts on using a stand.  I've used a pot on a burner directly on concrete without explosions. 

Having said that, lifting the pot a bit further away from the flame and creating a "chimney" around it helps with more complete gas combustion, better shielding of the flame and more efficient heating.  All of them save time and gas so its worth doing in my book.

[Brett Mason]

I'm using a couple of old foil oven liners to reflect the heat, and keep it cleaner. 

Originally on concrete like you and now on a brew stand clad in some kind of inflammable-ish fibre board. Doesn't seem to get too hot.

[Peter Smith]

I think it depends on your burner a bit, I brewed with 3 ring last weekend and I can have my hand under the burner while its on,  it doesn't seem to reflect much heat downwards.  

[Danny]

Wow - I brewed on Tuesday, had the burner on a piece of gib board (apparently not combustible) on the ground - I stuck my digital temperature probe under the burner, took it out after it got to about 110 degrees.

[Peter Smith]

i have an infrared heat gun thing,  will monitor concrete next time,  I have a stainless stand just need to commission a deck for it...