Saturday, November 28, 2015

Construction - Recap of the dirt and concrete phase from a DIY perspective

Naivety or Is It Perpetual Optimism?
Wow, I had no idea of the amount of time and effort that would lead up to building actually with wood.  As of early winter 2015, we have done dirt and concrete work for 15 months. I've been guilty of saying that, by the time we are ready to build with wood, the house will be half done!

Even after having roughed out the excavation into the side of the hill myself, it was hard to
Excavation roughed in (click on photo to enlarge it)
imagine the amount of heavy labor and machine time that would be required to build and install the French drains, to build and install the collector and conduits for the AGS system, to form and pour footings, to pour foundation walls, to backfill and compact it, to build retaining walls and do the landscaping necessary to control erosion while the house was being built. 

Lack of Experience
While I feel reasonably qualified to do carpentry, electric, plumbing, tile-setting, etc., I overestimated my ability to crash-course the dirt and concrete work.  It took very little time with the pros (that we reluctantly hired) to feel intimidated by their practical knowledge -- the kind that is indiscernible by reading or web-searching.  My early posts on this phase of the construction are testimony to my naivety.  If I had tried to follow through with those plans so confidently projected then, I would have burned significant time and money and had a compromised outcome.

As our excavation contractor operated the backhoe, I was usually handling the measuring
Real professional at work
rod for the rotating laser that guided his movements.  It is amazing the level of skill it took for him to stay within the tolerances of an inch or two, whether it was at the bottom of a trench or on the grade that under-girds the future slab floor.  

With the proper equipment he could provide and operate (as opposed to my over-doing with a track loader as I originally imagined), the French drains and the AGS conduits were installed with minimal disturbance of the soil on which the house will rest.   This is a huge advantage with our wind-blown loess soil which, when undisturbed, provides excellent support for a concrete slab even without the obligatory intervening layer of rock.

Concrete Work -- The Wide Footing
The footing under the concrete walls required 37 yards of concrete poured from a
Wide footing pour
conveyor truck.   As a DIYer, would I have been able to order the right amount of concrete and handle the conveyor after having never seen one before?  Maybe on the first account but not so likely on the second after seeing it done.  Would I have known to monitor the height of the pour with a laser instead of screeding off of the form?  No.

Concrete Work -- The Wall
For the week or so it took the contractor to set the forms, pour 36 yards of concrete and dismantle
Wall pour
the forms for the concrete wall, I was mostly a spectator.  At the end of the day, I was exhausted from merely watching the huge amount of physical effort that the process takes. For instance, 118  2' x 8' individual forms, weighing close to 100 lb a piece, had to be carried to the wall site, stood up and fastened to place. When the wall was poured using a pump truck, several hearty guys stood on top of the forms and teased the air out of the concrete by pumping 2 by 2s up and down to a depth of 8 or 10' at a time for the biggest part of an hour. And d
ismantling, carrying and stacking the forms and loading them for transport was no less arduous than setting them up for the pour.   Makes me wonder about the average life expectancy of concrete workers. 

Concrete Work -- The Narrow Footing and the Foundation Walls
Even though it was time-consuming, the narrow footing for the insulated concrete walls
Homemade forms for the narrow footing
was easily manageable for a DIYer with handy friends and family -- both the forms and the pouring.  Using wood for the forms was old fashion but I had the wood so the forms were free except for a few bucks to my friend who helped install them.

The insulated concrete form foundation wall is also easily within the reach of a DIYer  with regard to setting of the forms and pouring them.  Setting up the ICFs is straightforward if one follows the installation guide that the ICF manufacturer provides.

Slab-On-Grade Concrete Floor
Managing the rock sub-base under the slab was mostly a matter of providing guidance
Floor pour
the slinger-truck operator, viz., setting the grade pins and marking off the grade beams and piers . There was only a little tweaking for us to do with garden rakes and flat shovels after the truck had left.

When it came to pouring the floor, all I could do was watch while just under 1,700 sq ft of concrete was poured at one time.  If I had done it, it would have been in small increments so as to be able to use the previous increments(s) to screed off of, thereby necessitating perhaps as many as 8 separate pours.  And I would not have been able to have achieved the same quality of surface finish that the professionals did. 

Bottom Line
Despite not having budgeted for it ahead of time, the money spent for professional help was a good investment, especially since it allowed us to beat the winter weather and save several months building time.  Now it behooves me to find ways during the rest of the construction to recoup some of the outlay for professional help.

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