A Strong Foundation

The foundation came with a few hiccups. Our selected foundation contractor partnered with a builder and canceled all single home bids/contracts.  We spent 3 weeks trying to find a contractor who was willing to bid our project and had availability for late summer or early fall.  Luckily, we hooked up with Stockness, and the project lead was more than patient in dealing with us as first time owner builders.

Forming the footings

Pouring the footings

Footings are complete, and the inspection passed

The footings were poured the last week of August – Happy Labor Day to us!  We had the opportunity to subfill the basement (add the rock that would provide the structure for the basement slab) prior to the foundation walls being framed.  Our excavator was thrilled.  Apparently, not all foundation contractors allow the time for the excavators to bring in the fill between footings and walls which means scooping the rock over the top of the foundation walls to subfill.

Forming the walls

Ready to pour

Every cavity was filled using the boom from the street

Basement is complete, and the waterproofing is started

The wall forms were up in two days, and the concrete was poured on the third day.  The forms were pulled a week later and backfill was completed shortly after that.  We are excited to see the progress.

The lookout view from the future family room in the basement

Jared assessing the basement from the inside out

The concrete sub left the nuts washers for the framing sub to set the sill plates. 

Lessons learned:

-Pouring a foundation with a brick ledge requires a large amount of material waste.  We would select a product that does not require a ledge in the future.

-Waterproofing and insulating a foundation requires attention to detail.  Hire a capable contractor; we did not.

-With proper scheduling, subcontractors can be friends.  

-Have a backup plan for losing a contractor.  Otherwise, the project can be delayed by weeks.

For those interested in our technical research:

A house foundation has many functions – provide a structural base for the above ground structure, keep moisture from seeping through to the interior, insulate against temperature changes, and withstand the pressure of the earth around it (Check out this link for more technical details http://www.engr.psu.edu/phrc/Publications/BB0510-Insulating%20Basements%20Part%20I%20FINAL.pdf).  Realizing the importance of the foundation to the longevity of our home, we considered a variety of foundation options during the design process.  Here’s a summary of our findings:

Insulated concrete forms (ICF) are Lego-like blocks that interlock together.  The forms are filled with concrete and left in place.  This “green” technology does wonders for your energy bill IF used above ground where large changes in temperature can occur in a single day.  However, basements are protected from these fluctuations by the relatively stable temperature of the surrounding soil.  Additionally, ICF basements have to finished prior to receiving an occupancy permit for fire code reasons.  

Thermal mass (T-mass) construction consists of board insulation sandwiched between concrete.  The technology has similar benefits and performance to ICF without the need for finishing before occupancy.

Block foundations are becoming a construction technique of the past, because blocks are prone to leakage, cracking, and occasionally collapse (i.e. the home we had torn down).  Rebar reinforced core filling helps with the structural integrity, but one should expect on-going maintenance. 

Reinforced poured concrete foundations are constructed by setting up temporary forms, filling the forms with concrete, and removing the forms in 1-2 days.  Poured concrete overcomes the leaking and cracking concerns of block foundations. 

How does the cost compare between the four foundations we considered?  Block foundations are the most economical option, followed by poured concrete, ICF, and T-mass, respectively.  The ICF and T-mass quotes we received were between 30-50% higher than the poured foundation quotes.  We calculated the utilities savings for the ICF and T-mass versus a poured wall foundation with R-10 board insulation applied to the exterior and found it would take several decades to recover the cost of the more expensive options.