pouring concrete at -40F

[mark5]

I'm curious about something...
I know this guy (true story btw) that poured his foundation just 3 days ago in -13F outside temp. They covered it with some 'insulated tarps' with a heater inside, although there were some huge gaps where the tarps overlapped, and most of the heat blew right out.
They took off the forms after only just over 24 hours, put the tarps backs on, and on that night the temps dropped down to -35F.
Now its been another day, temp only got up to about -15F today, and expected to go down to near -40F again the next couple nights, AND....
This guy is pouring the basement floor in 2 days, with temps between -15 and -35F.
So my question...
This just seems horribly wrong to me, I mentioned it to him and his contractor assured him its not a problem. So am I just 'overly cautious'? What could potentially go wrong with pouring concrete at these kinds of temps? And how long before he actually see's a problem?
Again, I'm just curious, I'm no concrete expert by any means, but watching this happen just throws up a bunch of red flags for me.

[Wgoodrich]

I have said many times in the past concrete is like backing a cake. It all depends on the recipe and how you bake it whether it turns out good or bad.

Great concrete bunkers have been poured for scientific activities in the artic circle during the worst blizzards a person can imagine and the bunkers are still there.

When concrete is curing it will generate its own heat. The concern if the freezing of the surface of that concrete during the curing process, or the concrete becoming too cured due to lack of water and excess heat on the surface during the curing process. Then again if concrete is poured on frozen ground again can cause much problems.

The concrete poured in the arctic circle was poured directly to frozen ice deep in the ice from the surface. This could be done because the life of the building is expected not as long as it would take for that ice to melt and thaw. That is the key. If you pour a concrete floor on frozen ground that is going to thaw for the summer then refreeze expect that floor to heave, sink and crack or even break up.

As I started this reply. It is like baking a cake with many variables involved. Pour on frozen ground not good. Finding frozen ground only froze a few inches can be covered by a thermal blanket with heat applied removing the frost from the earth allowing it to be safely poured upon. Then even though that concrete is poured well below freezing ambient temperature it depends on if you installed thermal blankets to contain the heat produced by the curing of the concrete. If it is baby sitted properly and frost kept out and poured on earth that is without frost in it your concrete can be fine. Then calcium etc. can be added to speed up curing and generate more curing heat generated.

After reading this you should now pick up that yes concrete can be poured in almost any condition even underwater if the mix is right and the installation is right for the conditions.

Good Luck

Wg

[mark5]

One thing thats different here as opposed to the arctic circle is is does get extremely cold, but a few months later it can be extremely hot.
Just an example, on Feb.1 1996 here the windchill reading was -57.1 °C (-70.8 °F). On June 27 1996 (6 months later) the humidex reading was 46.1°C (115.0°F). Of course these are windchill/humidex readings, but it gives you an idea of how much of a severe change in temps from winter to summer are here. Roads, highways, and foundations don't last long here if they aren't built properly.
I do understand though, that pouring foundations in extreme cold can be successful, but I don't think these guys are quite up to the task, they seem to be taking a lot of shortcuts, and rushing the job.
I took a few pics, I'll show you what I mean, although tell me if I'm way off here, I mentioned a few things to this guy and he assures me everything is perfect and I'm worried for nothing, Ill post a couple pics in the next post.

[mark5]

hopefully this picture uploaded ok...
You can see the pipe was put down before they sprayed the wall, the container they sprayed from was for roofing, which I know is similar to foundation coatings, but still, I personally used a waterproof rubberized membrane on mine, not a dampproof roof coating, and when they sprayed, they covered the top of the pipe, clogging many of the slits.
The gravel just barely covers the pipe, which was laid directly on frozen ground, no stones or gravel underneath.
And here comes the backfill, man thats huge! The backfill was actually the clay earth that was drilled out when the poured the pillars that hold the foundation. This foundation is poured on pillars, there is no footing, and it was backfilled BEFORE the basement floor was poured.
So this just seems wrong to me, but anyways, heres a few other pics...

[mark5]

Heres a view from the front, just backfilled and ready to pour the front approach to the attached garage, which will be built in the upper-right corner of the picture, these are huge chunks of clay, there are also big pieces of concrete, and a fair amount of ice and snow mixed in as well. As of yet it has not been compacted or tamped, and Id be surprized if they do.

[mark5]

Just another view from the front, nothing quite beats that professional look of Tyvek housewrap being installed upside down.
And other things Im curious about is with the basement floor, should it not have been poured? Well I guess they couldnt have anyways, since don't have and water or sewer access right now, and the perf. drainage pipes are just sitting coiled up inside the foundation, they havent dug a sump pit or anything.

So I'm trying to be a nice guy, and tell my buddy, 'Hey, some of this just doesnt look right, you're paying top dollar for a pretty mediocre job which is more than likely going to have huge problems in just the first year or two.'
But I get the typical 'No, no, the contractor says thats how they do it, and all my plans were approved by engineers, so your worrying over nothing.'

So, I don't know, any thoughts? If not hope you enjoyed the story and pics anyways, I'll post more if I see anything else lookin a bit off as its getting done...

[Wgoodrich]

You will get much argument about what I am about to say from the builder and many others. However read the copied sections of the codes provided below and my interpretations of those rules and the whys that I provide then challenge those saying I am crazy to prove it by facts not just their opinions or the fact they have been doing it umpteen years. Doing it that way for umpteen years without research and change as technology grows is not what I consider a documentation of them being right. Kind of tells you I am expecting quite a bit of "your crazy" replies to you when you speak of what I am about to say. Just read the rules of law yourself or take it to an attorney and it should be confirmed if read by an open mind using prosessional interpretation techniques even when done by a layman.

The first thing in your replies that I picked up is the concern the basement floor was not poured before back fill. This is a concern. When backfilliing the new unbalanced fill puts pressure against that basement wall. The cured basement concrete floor resists movement of those walls causing tearing etc. not normally seen especially after backfill. Not a good move. Problem is the ground being frozen dictates the basement floor can not be poured on that frozen ground or by this summer you will find some very big cracks an heaves in that basmeent floor if poured on frozen ground. The basement is proceeding to make money not to build properly or it would not have been backfilled until the floor had been poured and cured then the basement walls at the top should have had the sill plate, bandboard, floorjoists and subfloor installed to hold the top of those basement walls from the pressure of that unbalanced load.

You mentioned they did not tamp that dirt in place. They can not pack that dirt or they will greatly increase the pressure of that unbalanced fill. Then you speak of frozen chunks of dirt, snow, ice mixed in that backfill. The bigger those chunks of dirt and ice the more likely it is that the perimeter drain hose will have been mashed and ruined by the impact of those dirt chunks ect. hitting on top of that stone bed just covering that hose. This will defunct the working ability of your subsurface drain system.

You hose seems to have been placed so the top of the hose is below where the basement floor is going to be. This is proper. They created their stone bed with what looks like 8s or smaller. The code requires one sieve size larger than the demension of the openings in that hose. The demension is not declared from either way. Your builder is looking at the hole as a slot saying pea gravel is bigger than that slot. The code does not limit that word demension to only one demension but rather it requires the stone bed to be one sieve size larger than any demension. That slot is 1/2" long normally requiring the smallest stone in that bed to be 3/4" in size.

If you went in the dryest month of the year to the gravel company and the loader picked up a pile of stone 3/4" in size no water would run out. Yet the same loader picks up pea gravel and you will see water pour out. Tells you that the #4 or larger is rip rap allowing water to pour through readily. The smaller you get in stone size from #4 and smaller creates more resistance to water flowing through it thus restricting the ability of that hose to accept water from sub surface dirt. Say the 4" hose is square for simplicity. You have 16" square touching that dirt to accept water from it. The 12" x 12" required stone bed is installed to greatly increase that by using rip rap allowing much open spaces between rocks creating an exposed area to earth to accept water to about 144" square to accept water from that earth.

COPIED SECTION IRC 2003

the drainage tiles or perforated pipe shall be placed on a minimum of 2
inches (51 mm) of washed gravel or crushed rock at least one sieve size larger than the tile joint opening or perforation and covered with not less than 6 inches (153 mm) of the same material.


I will post more in another reply.

Wg

[Wgoodrich]

Part 2 by Wg

While looking at the pictures I see the backfill going in yet do not see the required filter clothe being installed required to protect that stone bed already with too small pieces of stone from filling with dirt fines from the backfill.

COPIED SECION IRC 2003;

Gravel
or crushed stone drains shall extend at least 1 foot (305mm)be-
yond the outside edge of the footing and 6 inches (153 mm)
above the top of the footing and be covered with an approved
filter membrane material. The top of open joints of drain tiles
shall be protected with strips of building paper


OPINION;

You issued concern about the tar. Tar is an approved waterproofing material.

However while viewing the pictures I see drain hoses coming from the bottom of the future window wells connecting directly to the perimeter drain hose below. While the drain lines are required to serve those window wells they are to be emptied on top of the filter clothe down below and never directly connected to the perimeter drain hose below. Reason for this is that over the years as it rains etc. dirt fines will enter those window wells and be washed down those window well drain hoses. If the window well drain hoses does not end dumping onto the required filter clothe but rather directly connects to the perimeter drain hose below that dirt will wash into that perimter drain hose and settle and over a few years plug that permeter drain hose up to unusable for that basement thus flooding that basement.
This applies also to gutter drain lines from the roof. Actually this should be a separate drainage system installed over the top of the basement perimeter drain system. However some will also dump these gutter drains onto the filter cloth, in my opinion not a good idea but done many times by many.

The pictures depict flat ground. Then you speak of interior drain lines laying where the floor is to be poured. Then you speak of an interior sump pit. This is a desastorous set up. I am concerned, you speak of an interior and an exterior drianage system that I am picking up planned to drian into this inside sump pit. This would make a minimum of 2 and most likely 4 -4" gravity drain lines entering that basement sump pit. Be aware a 4" gravity drain line has a capacity of 300 gallons per minute flow. Multiply that times just 2 and you have a capacity of water entering that sump pit of 600 gallons per minute. Then if you actually have 4 pipes entering that pit you now have a gravity flow capacity of 1200 gallons a minute to enter that sump pit. If you ask your builder what size pump he is putting in to handle that much water, I am betting he is going to say he is going to put a big 1/2 or 3/4 horse 240 volt pump in. Most commonly one of those pumps builders normally put in have a capacity of 35 gallons per minute with 7 foot of head pressure. Think that one out. First your buider most likely will answer in horse power and voltage yet a pump is measured in gallon per minute with so much head. Head is measured by total verticle lift being about 7' in your case then distance to end of pipe compared to size of that pipe. May be as much as 100' of head or more greatly reducing the pump capacity when the head pressure is adjusted from it. Ask that builder to provide you with the perk loading rating of the soil around your basement and tier information of texture and massive of the subsurface soil. This info is provided by boaring tests done by a licensed soil scientist most likely no soil scientist has ever seen this building site. I am betting the basement was installed the way this builder and his father and grandfarther used to do it without any scientific facts just seat of the pants design. I suspect from the discription and info I have so far it will take between 120 to two 120 gallon a minute pumps to maintain a dry basement in heavy rain conditions. If you still have open trenches look for a change in soil texture showing a layer of solid clay. Depends on how deep that massive is and how fast the loading perk of the soil above as to how much water will be attacking that basement during high water seasons. This is what a soil scientist is for. The charge about 100 dollars per boaring and then you have info to tell you the size of pumps and even size of basement walls. Looks like you have 8" walls yet with clay and 7' of unbalanced fill that basement wall per code is required to be 10" thick with certain minimum rebar re-enforcement.

Your friend said an engineer engineered this building. I wonder if they have an engineer print on the wood construction yet no engineering on the basement. Saves money and sells to the homeowner that hasn't done their research. You are doing your research but I suspect when all is said and done the builder will have convinced the home owner and you will be less one friend. Just thought I would warn you of human nature. I have said plenty to get quite a reaction from those that don't know they don't know. Best shut up for now.

Let me know if you want more.

Good luck

Wg