Average time for slab to cure?

She&He+3+3 · Oct 08, 2008 7:39 pm

Just wondering about the average time that a slab is left to cure these days..
Our loam was laid yesterday, boxing is not far away & slab won't be far from being poured.
Our builder mentioned last week that the slab will go down an then "a couple of weeks" later the frame will go up. Now, I didn't ask their definition of 'a couple of weeks' but I thought the norm was at least four(?)
We really don't mind waiting 4/6 weeks if it means that there will be less likelyhood of movement & subsequent internal cracks to our home 18 months down the track.

What are your experiences with this?
How long did your builder leave the slab to cure before erecting the frame?

vanderlay · Oct 08, 2008 7:43 pm

Most volume builders don't even wait two weeks to start on the frame!! Not sure how this affects things longer term, but two weeks would probably be longer than average!!

donuts · Oct 08, 2008 7:43 pm

Hi Dee

Our frame went up something like 1-2 weeks after the slab - so not long at all. I checked with Kevin our building inspector, and he reckons it's ok for the frame to go on pretty soon, but anything heavy like roof tiles should wait longer (can't remember exactly how long though?).

Casa2 · Oct 08, 2008 7:54 pm

1-2 weeks for frame is OK, but as others have mentioned, anything heavy should wait. A slab continues curing indefinitely, but after 28 days it's good enough to take anything you want to throw at it.

Eager · Oct 08, 2008 8:02 pm

It takes me a long time to cure after a slab.

Oh, you're talking about concrete???? Yes, a week or two is about right until the frame starts to go up.

kexkez · Oct 08, 2008 8:06 pm

so if for something heavy it needs 4 weeks does that mean for double brick ( no frame) it would be 4 weeks not 1-2 weeks?

Last time we had the entire xmas break for our slab to cure so I haven't got any idea. Anyone in WA know?

to_do_list · Oct 08, 2008 8:11 pm

Concrete continues to cure basically in perpetuity but at a slower rate.

Reaches design strength in 28 days

Framing etc would be OK in a few days (say four) bricks and tile roofing I'd like it to wait a 3 to 4 weeks.

She&He+3+3 · Oct 08, 2008 8:47 pm

Really?
Wow, thanks for your replies! I thought maybe builders weeks might have been a bit like a bakers dozen :wink:

Quote:

Eager Posted: Wed Oct 08, 2008 8:02 pm
It takes me a long time to cure after a slab.

Oh, you're talking about concrete???? Yes, a week or two is about right until the frame starts to go up.

I like your humour Eager, gave us a good laugh!

KWOOD2 · Oct 08, 2008 9:14 pm

Yep, i've seen carpenters on site a week after the slab has been poured. It reaches most of it's strength within 24hrs (maybe 80% strength) and then becomes stiffer/harder for up to months if not years. As mentioned, 28 days is the norm before the slab should succum a heavy load.

Eager · Oct 08, 2008 9:17 pm

Hey, no problem!

BRRRRRRRRRRRRPPP!!!!
http://i249.photobucket.com/albums/gg226/LatVal63/barney.jpg

No, not really.

I_BUILD · Oct 08, 2008 9:20 pm

I have started frames within days of pouring and there is no problem with it at all. It wouldnt make a difference with cracking and in summer is probably a good thing to get the frame up and roof tiles on as soon as possible and also wrap up the house. The summer sun tends to dry out the slab too quickly resulting in alot of hair line cracks.

KWOOD2 · Oct 08, 2008 10:15 pm

I_BUILD

The summer sun tends to dry out the slab too quickly resulting in alot of hair line cracks.

That is why you must pour concrete in temperatures under 34C even for 20MPa concrete. If it's 40MPa concrete like I have recently poured...forget about it!

Pre-wetting the concrete and placing curing plastic ontop is the way to go to eliminate or reduce crazing and shrinkage cracks.

I_BUILD · Oct 08, 2008 10:45 pm

KWOOD2

That is why you must pour concrete in temperatures under 34C even for 20MPa concrete. If it's 40MPa concrete like I have recently poured...forget about it!

Pre-wetting the concrete and placing curing plastic ontop is the way to go to eliminate or reduce crazing and shrinkage cracks.

Ive seen owners spend days pouring buckets of water over there newly poured slabs in summer to try and avoid cracks from apearing lol

gettingThere · May 08, 2009 2:01 pm

I_BUILD

KWOOD2

That is why you must pour concrete in temperatures under 34C even for 20MPa concrete. If it's 40MPa concrete like I have recently poured...forget about it!

Pre-wetting the concrete and placing curing plastic ontop is the way to go to eliminate or reduce crazing and shrinkage cracks.

Ive seen owners spend days pouring buckets of water over there newly poured slabs in summer to try and avoid cracks from apearing lol

Is now the ideal time to be pouring concrete?

I hope it is

ICK · May 08, 2009 2:33 pm

I believe this Monday gone was the ideal time as thats when we got our slab!! :z:

Good topic, good information to know!!

vid · May 11, 2009 2:41 pm

ICK

I believe this Monday gone was the ideal time as thats when we got our slab!! :z:

Good topic, good information to know!!

I'm afraid your incorrect ICK, today is the IDEAL time for a slab, ours was poured TODAY all 89 cubic metres (18 trucks) of it!
Temp in Adelaide is 19 today, 18 tomorrow, 17 on Wednesday with a shower or 2 probably pretty good temperatures from what I read!

ICK · May 11, 2009 5:53 pm

Good feeling isn't it vid? Now can't wait for the frame which is going up later this week!!

vid · May 11, 2009 6:06 pm

ICK

Good feeling isn't it vid? Now can't wait for the frame which is going up later this week!!

It's great finally feels like the whole process is REALLY getting some speed up, we live right next door so I was able to observe them doing the slab for quite a portion of it, those guys really know what they are doing and it's a long hard day for them, they arrived at 5.15am and left about 3pm, they only seemed to stop for a few minutes the whole time.

vid · May 13, 2009 8:49 am

We just had some rain and we have some water pooling in a couple of areas on the new slab should I be concerned about this ?

Casa2 · May 13, 2009 12:59 pm

vid

We just had some rain and we have some water pooling in a couple of areas on the new slab should I be concerned about this ?

Yes ... you want water to pool everywhere on your slab to help it cure