protecting a slab exposed to the elements

[astidham]

Anyone have an idea how to protect a slabe exposed to the elements for a exrended amount of time?
The concrete guy said thompsons water seal works pretty good, but im thinking that it might be exposed for about 4 months through the winter months before I can start framing. 
Maybe I should just hold off on the slab? Im afraid the price might change significantly if I wait.

[MountainDon]

I'm not sure what the worry is.

We have concrete driveways and parking pads; 28 years is the oldest, another is 10 years and the third is being done currently; I have two more sections to do in the next few days. The oldest (28 years) is not quite as pretty as the 10 year old due to some oil spots and dripped paint spots. But as a slab to build a structure on I don't see any problems.   Maybe I'm missing something?  Our ten year old drive/parking slabs look about the way they did when new.

[astidham]

I'm not sure what the worry is.

We have concrete driveways and parking pads; 28 years is the oldest, another is 10 years and the third is being done currently; I have two more sections to do in the next few days. The oldest (28 years) is not quite as pretty as the 10 year old due to some oil spots and dripped paint spots. But as a slab to build a structure on I don't see any problems.   Maybe I'm missing something?  Our ten year old drive/parking slabs look about the way they did when new.

I was over thinking it. I just needed someone to point it out...
Thanks Don!

[rick91351]

The only thing I would worry about is if you pour to late you might have to have concrete blankets until it is cured so I would say as soon ASAP....

As far as subjecting to to a lot of weather it is not like it will warp.... Though I had ideas of such; just to pull your chain but MD messed that all up.     Not the first time he has taken away my thunder before lighting struck.   

[MountainDon]

Too much time on my hands at night.   


Ditto on the blankets though. Getting too cold to do without.

[Don_P]

Air entrainment, no extra water, warm water from the plant and then baby it for at least a week. I've poured in the Dakotas in winter, Dad has poured north of Moscow in Feb... but, I lost one just after Thanksgiving a few years ago. It was a 4 truck pour, the new driver of truck 3 got lost and arrived after truck 4. He had gotten scared and watered his load en route, lost the air entrainment and poured soup. The finishers hopped on it too hard and too fast. It then began a freezing rain that lasted for 2 days and we had no blankets. Generally when things go wrong everything is wrong. That area spalled badly. Oh and we had radiant tubing in there as well  . I kept thinking "if I had some way to circulate heat in that tubing right now." One reason to have a contractor do it is it becomes his problem.

another way to do it is to build stemwalls, construct the building on them and pour a floating slab within the building later. The slab is then not structural to the building, if the fill under it needs to settle it does not crack over the rigid footings. The building can then also be heated. The slab effectively becomes a rug.

[rick91351]

Don_P does bring up a good point.  And a reason IMHO that it is just better to pour your footing or footer and stem walls.  Build the building then pour the floor if you have to.  If you have the weather on your side pour the slab then the building. 

If you live in an area where there are a lot freak rain storms or snows.  Areas where freak storms are a way of life..... Life is so much easier when you have a roof over your head.  Let it rain and just listen to the pitter patter is a lot better than watching the rain lift and wash the cream off the top.  Then you are back demoing all that expensive concrete.  Then having to pay to dump it and pay to re-pour.  Same goes in the summer time like around here where if we get a summer rain we get on national news feeds so it seems.  But the sun can just bake down on your pour and those hot winds start to blow and it just pulls the moisture out of a slab so quickly.  But if you are under a nice roof watching it start to set up normally WOW life is good!             

[Squirl]

You can order it with type III Portland cement for a faster set.  Also, the higher the psi,  the better the weathering capabilities and it should just last longer.  Average concrete can handle up to about 4000 psi with minimal extra cost.  Most concrete engineering is for 4000 psi because it gives the maximum strength to cost.  Each sack of cement per yard (usually about $10 per sack) gives about an extra 500 psi.

The only problem I could see is that water might get under the slab and frost heave.  Don mentioned sidewalks and driveways.  I mentioned in my other post about isolation joints.  These are usually in concrete pours exposed to frost heaving and I prefer them to control joints.  Isolation joints are commonly used to separate slabs from frost walls and post footings.

http://www.concretenetwork.com/concrete-joints/isolation-joints.html

[astidham]

The only thing I would worry about is if you pour to late you might have to have concrete blankets until it is cured so I would say as soon ASAP....

As far as subjecting to to a lot of weather it is not like it will warp.... Though I had ideas of such; just to pull your chain but MD messed that all up.     Not the first time he has taken away my thunder before lighting struck.   

Thanks, i would probably spent hours on the computer looking up "warped concrete"   lol
good thing MountainDon jumped in early!

Don_p, sounds like when it rains it pours... luckily the local concrete plant is about 6 miles from my house!

Squirl, the concrete guy said he would use 3500psi, should I ask him to go with 4000?

Thanks to everyone for their helpful information.

[MountainDon]

FWIW, when our house was built the monolithic slab was placed in December. December in NM means freezing nights, every night. The house walls were started 10 days after the slab was placed. The house never saw heat until spring; May.  The slab did show some fine cracks here and there when the original flooring was pulled about 10-12 years after building. But nothing serious and now those are all hidden under ceramic tile.

[Squirl]

3500 should be enough for severe weather concrete.

http://publicecodes.cyberregs.com/st/ny/st/b400v10/st_ny_st_b400v10_4_par010.htm