cement & temp's

[NewEnglandRaceFan]

I'm going to be pouring a 2" floor for under my breezeway so I can use the space for storage.

It gets cold at night now, high 20"s low 30's
is that to cold, it warms up to mid fifties ,
will it getting to 30* at night harm it, if it's poured 10 hours before it gets that could?
or do I need to keep the area heated and for how long?

Thanks

[daved931]

The big thing is to be sure the ground is not frozen already. You cannot pour cement onto frozen ground.

Are you going to have a slump test done? You want to make sure that you have a lower water to mix ratio than you would in hot weather. Some companies will allow you to ask for a for a heated mix.

Make sure your cement does not freeze before it can cure properly. This may require insulated blankets or heaters. The first 24 hours are the most critical.

[NewEnglandRaceFan]

The big thing is to be sure the ground is not frozen already. You cannot pour cement onto frozen ground.

Are you going to have a slump test done? You want to make sure that you have a lower water to mix ratio than you would in hot weather. Some companies will allow you to ask for a for a heated mix.

Make sure your cement does not freeze before it can cure properly. This may require insulated blankets or heaters. The first 24 hours are the most critical.

thanks, this is just a 8.5'x9' pad under the inclosed breezeway, 3 block walls, and the 4th is studs as t's the one connecting the garage.. it's nothing fancy, just to use as storage space and not have things on dirt.. I can heat it from the garage end with heaer and fan, the ground won't freeze yet..
the crawl space is 2.75' tall an is wasted space and because wife wants to install a new floor in breezeway (cork iirc)
I'll use this to pour the slab and make the space useable

[Dan Barlow]

Id keep it above 40 for at least a week. We did this for the little ladys ex boss ( before he stuck her in the back with the dagger ) the floor turned out well.

[Jimbo17]

I have a few questions.

First is there a footing that is at least 40" deep?

You cannot just pour concrete on the ground without some type of stem wall around it. If you have a stem wall I still don't think I would feel comfortable with a 2" thick slab of concrete. I would make it 4"

When pouring cement in cold weather they usually had a product like Anti-Hydro to make it set up faster.

I build new homes for years and we were always pouring concrete sidewalks and driveways.

Just my opinion. Jimbo

[Barry Donovan]

I remember working concrete nearly any weather. As long as the chain keeps moving it goes through to what we call dry. There is stuff to add as well, keep it busy. Ground is still warm anyway, just do it.

As memory has it.. we worked a couple of Decembers. Frozen fingers and warm concrete. Many hours all at once.

[SuperBuickGuy]

Pouring concrete in cold weather isn't an issue - it's actually hot weather that causes the problem (dries too fast). The chemical reaction in the concrete will keep the water in the mix from freezing. With that said, if you pour on frozen ground, you'll heat the ground and make it melt - which will result in wavy, crack-prone walkways. The fix is simply pour over gravel (3/4 minus) to keep the ground frozen.
You're pouring in a covered space - so honestly, pour it and trust your batch plant to do the right mix.... I don't know how much I've poured (I was a general contractor before law school), but I do know that the concrete company is your friend - tell them what you're doing and they'll come up with instructions and mix that will work well.

[NewEnglandRaceFan]

I have a few questions.

First is there a footing that is at least 40" deep?

You cannot just pour concrete on the ground without some type of stem wall around it. If you have a stem wall I still don't think I would feel comfortable with a 2" thick slab of concrete. I would make it 4"

When pouring cement in cold weather they usually had a product like Anti-Hydro to make it set up faster.

I build new homes for years and we were always pouring concrete sidewalks and driveways.

Just my opinion. Jimbo

IT'S A SLAB FOR STORAGE, it doesn't need a footing, the breezeways walls footings will be more than enough, it's for basic storage, you know like x-mas displays, spare parts, odd ball stuff you only use at one part of the year, and camping gear,,
a 2" slab will be more than enough..

[NewEnglandRaceFan]

Pouring concrete in cold weather isn't an issue - it's actually hot weather that causes the problem (dries too fast). The chemical reaction in the concrete will keep the water in the mix from freezing. With that said, if you pour on frozen ground, you'll heat the ground and make it melt - which will result in wavy, crack-prone walkways. The fix is simply pour over gravel (3/4 minus) to keep the ground frozen.
You're pouring in a covered space - so honestly, pour it and trust your batch plant to do the right mix.... I don't know how much I've poured (I was a general contractor before law school), but I do know that the concrete company is your friend - tell them what you're doing and they'll come up with instructions and mix that will work well.

lol trust your batch plant,, That's me getting 8,80lb bags(math formula/ calculator) came out with needing6.5 bags, I'll mix 8 and firing up my cast iron mixer and going to town..
Ofcourse that's after I get the vinyl flooring up, that they used tar paper and glue under it, taking a air hammer chisel and welding a putty knife to it, and buzz it off the planks

[SuperBuickGuy]

lol trust your batch plant,, That's me getting 8,80lb bags(math formula/ calculator) came out with needing6.5 bags, I'll mix 8 and firing up my cast iron mixer and going to town..

then put a layer down if the ground is frozen and knock yourself out.... (not literally dammit)

[Huskinhano]

I remember when I was an electrician's helper one winter working in a housing development. It was bitter cold, like in the single digits. It looked like the masons were pouring just about straight antifreeze into the tubs of mud they were mixing. They had to have salamanders blowing right on the tubs to keep it from freezing. When they troweled the mud on the outside block walls of the basement they were working on, the mud froze right in place. In the spring it was falling off.

[68scott385]

Many contracts here are worded such that the ambient temperature for the day of the concrete pour must reach a minimum of 45*F or we could not pour, but my forte was walls, not slabs.