Rebar width in mm?

[Mullins]

Hello Gents,

I have dug my foundation, and I am now ordering my gravel, concrete and rebar to get cracking on the next phase of the build. I am going for a 36 igloo.

What width in mm are we talking for the rebar? I am in Europe so options are 6mm, 8mm, 10mm and 12mm. I am swaying towards 8mm, but just want to double check, as I have no idea!!!

Thanks for all the help, forum is a wonderful resource!

Eoin

[Gulf]

I'm wondering if those numbers are a bar size. When I convert those metric numbers to inches, I get some very small numbers for rebar. The most common size for rebar (over here) that would be used in a light foundation is 1/2". 1/2" converts to 12.7 mm. 8mm, would be too thin imo. I did a quick search and looked at some imperial and european rebar size charts. I just got more confused. Double check what actual diameters the 6, 8. 10, and 12 choices actually are.

[david s]

You can use a smaller diam bar, but you just need more of them. Reinforcing bars are made with a patterned surface for increased grip, but a plain round bar is ok. You can also use some old steel pipe if you have any laying around.

[Mullins]

I'm wondering if those numbers are a bar size. When I convert those metric numbers to inches, I get some very small numbers for rebar. The most common size for rebar (over here) that would be used in a light foundation is 1/2". 1/2" converts to 12.7 mm. 8mm, would be too thin imo. I did a quick search and looked at some imperial and european rebar size charts. I just got more confused. Double check what actual diameters the 6, 8. 10, and 12 choices actually are.

Thanks Gulf,

I double checked the measurements when I was passing the store yesterday. They are in millimetres and not a size.

It may be my memory (as it was 15 years ago when I last did a Summer of construction work). I am nearly sure the construction company used rebar 5 and 6 in foundation work in San Francisco and Bay Area. Number 5 is 16 mm I believe?

As I'm not building a house, and I'm not in an earthquake zone, my thinking was 8mm would be enough... Happy to be guided by people with more experience...

Cheers

Eoin

[Gulf]

Yes Eoin, over here, #5 and #6 are 5/8" and 3/4" (or 15.87 mm and 19.05). Since, I don't know anything about your local soil conditions and I think that Luxembourg has some extremely cold winters, here is my advice. I would pour a 5 1/2" (150 mm) slab with a 12 mm rebar grid on on 12" (300 mm) centers. That is about the average of what you would see if you searched many of the more recent builds on this forum. Overkill? Probably.

[Mullins]

Thanks Gulf,

I don't think it would hit the same lows as the US Midwest, but it would get to -5 degrees Fahrenheit to +5 for 3/4 weeks every winter. Better safe than sorry, and go with the 12mm. Plan is to pour 5 1/2" alright.

Thanks for the feedback

Eoin