Cold Weather Construction and Concrete

? ? Re: (bottom paragraph) ~ "There are a variety of techniques ... for finishing concrete in cold weather.... crews can build a temporary enclosure and heat the inside air, typically with propane heaters. This hot, dry air can cause the concrete's surface to dry out quickly, however, resulting in crusting and cracking."

The Protective Coatings Experts teach otherwise : propane heaters do NOT produce "dry" air.

Memory might be off a smidge, but, burning a gallon of propane produces a bit more than 3/4 of a gallon of water (as water vapor, of course) ... making the warm-air rather humid, as opposed to 'dry'. [3CH8 + 5O2 > 3CO2 + 4H2O]

That is, of course, unless the heaters they are referring-to have a heat exchanger (as in your home's central heating unit).....

~ Just " Keeping-it-real " ~

Hi Tom,

I understand and agree with you about the production of water vapour by burning propane but concrete poured in very cold conditions are still "crusting and cracking".

Ice, the solid water in the mix doesn't react with Portland cement at the moment of pouring the concrete, it reacts later, sometimes months later. This is the problem. Just look around and see how the bridges or other winter projects are. Rusting rebars, cracked concrete, and more damages. The same work made during warmer temperature conditions is good, without defects.

Can we do things the correct ways without defects? Defects cost more than we can pay, isn't it? So, we have to do without defects, Gil.

Re: "The same work made during warmer temperature conditions is good, without defects....Can we do things the correct ways without defects? Defects cost more than we can pay, (don't they)?"

Seems to me that you answered your own question quite thoroughly and completely.

Large-scale construction projects certainly must adhere to rigorous time-lines, or be stricken with cost overruns. However, when 'nature' imposes such deliterious effects on a project, as do frost/ice/snow/torrential rains, etc., then we must either:

a) be willing to live with the defects caused by same // b) plan-ahead on spending sufficient monies to control the environment around said project // c) plan-ahead such that work will only take place during acceptable weather windows // or, d) implement construction techniques that are unaffected by weather obstacles.

"a" (living with defects) is not normally going to be an acceptable solution. And, more often than not, "b" would impose too great an additional cost to justify. "d" is an option that will certainly challenge even the best engineer, when it comes to working in the mud/snow/ice at ground level.

"c" is an option that is easily sloughed-off as absurd or unfeasible. That is because we are human, and have learned to depend on brute force (and our 'will') to overcome any and all obstacles, at any cost.

If we had been created to think and work more like ants or bees, I'll bet society would attack large-scale infrastructure projects MUCH differently....

Just my 2-cents worth ~~~

Hi Tom,

I can agree on your observation! Answer to question, however, I work with or more precisely "on" concrete for over 50 years and I saw disasters after disasters. It's proper to the concrete working habits. Again, this is my observation. If you visit a street with new housing project and check the condition of concrete works in front of garages, around swimming pools, you can see defects over defect (scaling, cracking, and need to eliminate millimetre of concrete from the surface before coating with anything at choice), I am not here to criticize cracks on walls and basements.

During my working life, I have difficulties to stain and seal many concrete works without sandblasting. Cracking and dusting surfaces are common. Concrete jobs are quoted (3,500 psi) but delivered (2,000 psi) different compositions and application (trowel finish to broomed). Is it a regular and normal way to work with concrete? Or no one reads how to work with concrete? Also, don't forget "greed" for profits!

I recognize that I made the answer to myself but when statistically we can demonstrate that winter or cold weather concrete works are with defects, we have to stop and work in warmer conditions.

Imagine the automobile, washing machine, television making industries and other high selling products we make with the same lousy work and with so many defects, we could not sell anything and our economy will be in jeopardy.

I understand your explanations about conditions and application difficulties but nothing is easy. Tom, we are fine! You tell what's good and how to do well with concrete. I just observe what's done in general. Also, we will not change the situation of concrete works, not in close future, guarranteed! Concrete is an important part of our life and must be respected for its functions, Gil.

Per your comment that "(you) have worked on concrete for over 50 years and (have seen) disaster after disaster..."

My Post(#6) here reiterates a favorite adage:

"You don't necessarily get what you pay for ... you get what you INSPECT!"

EVERY job should begin with a thoroughly written (articulate and complete, to the last detail) SPECIFICATION ... and then, a qualified Inspector should be on-hand from beginning to end, *enforcing* the Specification. [Period]

That proverbial ol' ounce-of-prevention . . .

Hi Tom,

Suppose that you are a home-buyer. You bought the land, approved the design of your future house, stamped by an architect, give money to the contractor to build. If you are not a knowledgeable individual in CONCRETE, you cannot INSPECT, and most importantly, you cannot EXPECT a well build house for you and your family. Sorry, you have 50% chance to be satisfied!

I agree with you about EVERY SPEC you want but the reality on the jobsite shows different from the SPECS.

You are ENFORCED to live in your SPEC build house and spend some money from your pocket to make improvements and REPAIRS. [PERIOD]!!!

Only the governement can correct and collect. Eventually your bank has all PREVENTIONS, never you, Gil.

Re your comment: "If you are not a knowledgeable individual in CONCRETE, you cannot INSPECT, and most importantly, you cannot EXPECT a well build house for you and your family."

IF you had read my message linked above , all-the-way-through to the end, you would have seen the "caveat" :

"...and then make sure a qualified inspector is there to enforce the specification."

Granted, there isn't a single solitary "average-Joe" fresh out of high school (or college for that matter) who knows how to inspect ANYTHING properly ... shoelaces included!

Very few, if any such individuals are properly equipped to "kick-the-tires" before purchasing a used car. And certainly, they are likewise unprepared for inspecting a HOME prior to purchasing one. That is why there has been such phenomenal growth in the "Home Inspector" business the past few decades.

Note: I am not suggesting in the SLIGHTEST that "any old home inspector" is properly trained and equipped to perform a proper inspection on a slab-pour.

Just about EVERY inspection task that is worthy of being undertaken in the first place warrants looking into the COMPETANCE of the person being considered to perform the inspection. [By-the-Way: in recent years there have been numerous articles addressing the fact that there is a worldwide shortage of qualified inspection personnel ... shortages involving MANY different 'arenas' of construction, manufacturing, transportation, etc.]

And ~ the more expensive the article (or structure), and the more complex the scope of the inspection , the more one should EXPECT to pay for a properly executed job.

And ... though THIS should go without saying ... the more thorough the "interrogation-work" (and the more you pay), the more thorough / detailed and meticulously written should be the report on same.

[ I stand by the original comment , in the entirety of its context ...]

Hi Tom,

I want to close our differences. I don't want to win. I just want to tell you what is what, in reality.

If you want to see what I am talking, visit INNISFIL, Ontario. A new town North of Toronto and on exellent if not the best agricultural land (It's a shame!), builders operate during last few years and you can see disasters in every house. Each house is sold for over $250,000. Every basement must use epoxy injection to eliminate water infiltration. Redo all concrete surfaces, garage and entrance, and back of the house. Just watch the quality of the coatings (paints).

Wish you good luck and let me know what's happening with concrete, Gil.

...No "differences", I am sure...simply unfulfilled/incomplete communication...

You have now interjected: "Every basement must use epoxy injection to eliminate water infiltration."... that's a whole different ball-game than roadway/bridge construction.

Although this is NOT a solution for all of the problems you've mentioned, there are products such as Xypex <_Link , which (according to lots of documentation, much of which is corroborated by Corps of Engineers studies) can effect dramatic improvements with respect to prevention of permeation.

I'm sure there is much research yet to be done ... but MUCH has already been accomplished. As W. Edwards Deming stated:

"It is NOT enough to simply do your best. You must FIRST know WHAT to do, and THEN do your best."

Blessings to all ~