Tilt Wall Design
Greetings!
We’ve been working on a home design for quite some time and have finally settled on a floor plan. We are now looking into various wall systems, but I haven’t found a “perfect solution” in my research.
The system I’m now considering is basically an ICF without the exterior foam.
file:///C:/Users/adam_/OneDrive/Documents/Tilt%20Wall%201.pdf
I’m considering this wall vs ICF for two main reasons:
1. It would allow me to stamp the exterior concrete to create the wall finish.
2. We live on the property now and have struggled with carpenter ants and bees. My neighbors had termites, so I’m hesitant to put foam on the exterior.
The property is in Fort Worth, TX (Zone 3).
Fox Blocks has a plant near me, so shipping shouldn’t be too hateful.
http://www.foxblocks.com/products/fox-tilt-up/straight-panel/
The plan would be to lift the concrete and foam as a tilt wall and then screw the studs into the fox blocks for mechanical and drywall.
Any suggestions or thoughts on this idea?
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Wall drawing take 2:
My one concern is with the steel framing. You will get R-10 or so from the Fox Blocks. The stud wall will only add another R-6 or 7 due to the high thermal conductivity of the studs. If this meets your needs, great; just be aware that the R value of the stud wall layer is only about 1/2 what you would expect based on the center-of-cavity R.
Also, if you go with this system, make sure that the blown-in material is either fiberglass or all-borate cellulose; cheap cellulose with ammonium sulfate will corrode the studs.
Thanks Jon!
That is a lower than I'd like. I was thinking closer R-20 total, but see where the studs reduce that.
I'm trying to reach north of R-20 for the whole wall. With that in mind, I've looked around and something like the wall attached below looks interesting.
If I'm thinking right, this should give:
Fox Block = R-11
Polyiso = R-12
Concrete = R-1
=R-25 center of cavity
I would screw fir strips directly to fox blocks to create a wiring chase. Still researching, may need to be a little deeper to accommodate boxes, but that space could potentially be fiber filled for another few points.
Adam,
It sounds like you are well on your way to figuring out the details of your preferred wall. My own experience is that any project with a rarely-used construction method -- that would include tilt-up concrete walls on a residential site -- ends up with several surprises and "oops!" moments. You and your construction crew will be learning a lot about tilt-up walls on this project. In other words, the first job is your practice house.
Good luck.
You need this: http://dukaneprecast.com/products_applications_precast_products.html
http://dukaneprecast.com/pdfs_design/DOUBLE-WALL.pdf The double wall system has concrete on both sides, foam insulation in the middle. Not sure if there is something similar in your area.
They are closed today, but I will reach out to see if pricing is on par with what I found locally.
Speed Fab-Crete is my local tilt wall construction co. and one of their salesmen is who brought up the single wythe options for residential. SFC is strictly commercial where Dukane seems to have experience in residential.
For reference, this is one of the companies that offers a single wythe panel.
http://www.superiorwalls.com/superior-walls-products/ag-wall-superior-walls/
I haven't been able to get Superior on the phone to discuss costs, but shipping would likely kill the deal anyway.
I like the sandwich precast panels, but they have two main downsides:
1. Cost - installed costs are around $20 per square foot (ball park from SFC)
2. Adaptability - The wire runs and plumbing are cast into the wall. Changes after pour are next to impossible.
For a 10x 10 section of tilt wall as described I'm estimating costs at:
Steel reinforcement = $115 (#4 12" OC)
Concrete =$90 (.875 yrds)
Fox Block = $150 (est for 29 straights panels)
Polyiso = $95 (3.2 sheets 2" foil faced)
Fir Strips = $15
Grand total = $465 or $4.65 per foot
If you assume double the cost for labor, I'd be somewhere around $10 PSF. Still probably almost x4 of stick framing, but 1/2 of precast.