How thick concrete floor in hobby room

[Chrissofsweden]

At the back of my asphalt-paved garage, I plan to build a hobby room of about 3x3.5m. There's just regular gravel under the asphalt that can easily be chipped away. The plan is to build a partition wall and cast a simple insulated floor.

Think 5cm of cell foam and a layer of concrete. Is 5cm of concrete with reinforcement enough?

I should be able to mix that myself if I have a mixer?

 

[KnockOnWood]

Why concrete?
I think it would be simpler with some studs with foam insulation in between, and then a simple, rustic wooden floor.
Nice, and comfortable to stand and walk on.
But it probably also depends on what your hobby is...

 

[Chrissofsweden]

Sharpening of edge tools in all its forms, tool renovation, some small tinkering with fire starters, etc.

I imagine there's a risk of moisture from below if using wooden beams? Some water also splashes from cooling when grinding. Occasionally, a can of water gets knocked over too.

I have a belt grinder 2000x50mm, polishing machine, Tormek, drill press, disc sander. But everything is balanced, so it doesn't vibrate a lot.

 

[elpaco]

I'll let someone knowledgeable answer about the thickness, but it spontaneously feels thin. I would have probably poured 10cm. Can't you dig out a little - what's underneath?

For casting - 1 m2, 1 dm down gives 100 liters, or 1 cubic meter of concrete for 10m2. I recommend renting a forced mixer, 80 or 100l. Incredibly convenient to work with, and fast (5min). Buy casting gravel so you have sand/gravel already mixed.

 

[justusandersson]

7 cm is probably some sort of minimum measurement with traditional reinforcement. Especially since you're planning to mix the concrete yourself. It's worth renting equipment, both a mixer and a vibrator.

 

[Chrissofsweden]

There will be no weights or particular stresses on the floor. The room will be 12-15 square meters and used as a small technical workshop

But 7cm is a concrete answer I thank you for

 

[Chrissofsweden]

I'll let someone informed answer about the thickness, but spontaneously it feels thin. I would have probably cast 10 cm. Can you dig out a bit - what is underneath?

For casting - 1 m2 1 dm down gives 100 liters, or 1 cubic meter of concrete for 10 m2. I recommend renting a forced mixer, 80 or 100l. Incredibly easy to deal with, and fast (5min). Buy casting gravel so you have sand/gravel already mixed.

Really good tip to rent a mortar mixer. About 900 SEK with VAT for two days will ease the process a lot. Almost makes you tempted to redo the basement as well

 

[Peter2400]

I would have been more inclined to pour a couple of cm of self-leveling compound on top of the asphalt, what could go wrong? A couple of fine cracks I could live with in a hobby room.

 

[Chrissofsweden]

I would have been more keen to pour a couple of cm of leveling compound on top of the asphalt, what could go wrong? A few minor cracks I could live with in a hobby room.

The asphalt ends 1.3m from the wall where the room is to be built