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icf vs block foundation

Started by addicted, May 01, 2017, 08:41:52 PM

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addicted

I don't want to start a fight.  I would just like to know from a diy point of view towards icf or block for a timber frame. Right now I'm designing a walkout basement with pilasters to support the frame. My costs are about the same for block with 4 inches of xps vs icf with similar rvalue as advertised by the manufacturer. The difference Im coming up with right away is time. Im guessing 100 block a day for 1600 block equals a couple of weeks of perfect weather and time availability vs one week for icfs. However I haven't been able to source braces for icfs yet but the zuckle looks cost affective and I have seen them for sale used.
Im open to any advice from guys that have used either foundation and why they prefer a certain method.
Thanks in advance.
Rusty

flyingparks

Fox Block is a great product. To be honest, I haven't used block foundation so I have no basis for comparison. ICFs are lighter and seem to be easier to use...especially from a DIY standpoint. Some steps, like adding XPS to block foundation, are eliminated. Fox Blocks are reversible, meaning you can flip them every anywhichway and they will still snap together, which is why I use them. Just be sure to brace more than you think you need: nothing quite like a blowout to keep one's ego in check.  :)

Ljohnsaw

Considered an ICF but little bracing is required.  I used FasWall blocks.  85% shredded pallets, 15% Portland cement. You can do 6' lifts (per the recommendation), I did 9' on one corner and the sales guy said the "experts" will do 12' lifts.  All about the concrete mix and enough labor.  I did mine with one helper and a pump crew.  The second lift was 6'.  This was over the door ways so I removed the insulation (3" of rock wool).

 
 

 

I can provide contact info if you would like to talk with my salesman.
John Sawicky

Just North-East of Sacramento...

SkyTrak 9038, Ford 545D FEL, Davis Little Monster backhoe, Case 16+4 Trencher, Home Built 42" capacity/36" cut Bandmill up to 54' long - using it all to build a timber frame cabin.

Raider Bill

I used AMVIC ICF. Supplier provided the bracing free. First lift was 12 foot. All blocks were reversible. Pretty DanG easy considering it was the first time I'd ever seen ICF blocks when the delivery truck showed up with my 666 block load.


  

  

 
The First 70 years of childhood is always the hardest.

Don P

I've used both. I've had a blowout on ICF's which wasn't the end of the world but did cause some scrambling and was glad we had an extra hand that day. I've had blowouts with poured walls too. We had an excavator hit an ICF wall with his bucket on one job and that was, different. We couldn't see the structure to see whether it was damaged or not. My other concern is providing insects with a path up to the frame, never had trouble just concerns. I can also throw another way into the mix. I've built on Superior walls a couple of times. They worked well and are installed in a day on a gravel footing, insulated, studded, electrical chases and no foam outside so my insect concerns were relieved. I think their engineering is a little lightweight but it is a good product.

addicted

Thanks Don
how do most people line up their posts on a superior wall? Ive never seen a profile of that detail. would be nice to see how timber frames are incorporated into that system.
Rusty

Don P

We gave Superior the TF plan and their engineer packed together their stud sections according to the point loads above. In a few locations where we had serious point loads they also specced concrete cookies under the walls on the gravel to help distribute the loads over a wider footprint than just the wall alone. An engineer friend visited the first one during construction and pointed out a few details, I had him look over things beforehand on the second but don't recall any changes being needed, so I think it was maybe a case of us all growing with time. Both houses have been trouble free foundationwise, one is about 8, the other about 5 years old. There are several others in that neighborhood using their first generation system with wood nailers instead of steel that have also been trouble free to my knowledge. You can find prescriptive language for their footings in the code in the same area as the pwf language.

Ljohnsaw

Quote from: Don P on May 02, 2017, 03:55:07 PM
My other concern is providing insects with a path up to the frame, never had trouble just concerns.

I was concerned with insects as well with my FasWall.  The wood is treated with acid (to remove the sugars they say) so termites won't be interested.  The block is a little porous so I was concerned about ants.  Standard insulation is Polyiso (the yellow crunchy stuff) or you can switch to rock wool (slightly cheaper).  I had ants completely devour polyiso insulation in a pump house so I was having none of that.  The only issue I had with the rock wool is it took me two winters to build.  In the spring, snow melt during freeze thaw cycles saturated the rock wool.  That made the blocks very heavy and since the insulation value is good, the saturated rock wool was frozen to each other in the middle of the stacks even though the surrounding snow was long gone.
John Sawicky

Just North-East of Sacramento...

SkyTrak 9038, Ford 545D FEL, Davis Little Monster backhoe, Case 16+4 Trencher, Home Built 42" capacity/36" cut Bandmill up to 54' long - using it all to build a timber frame cabin.

witterbound

My frame sits on top of my first floor deck.  I've got a full icf walkout basement under it.  I embedded strapping in the Icfs that ultimate got nailed to the outside of my posts.  I simply added blocking under my floor to the icf to support the post point loads.  Didn't have it engineered.  Haven't had any issues after 10 years.

logman

I used Superior Walls on my home and like them a lot.  They go up quick and easy and you only have to get the concrete trucks in once.  My basement is almost as warm as my house but nice and cool in the summer.  My engineer speced additional footer pads under all my post locations which Superior Walls provided.  There is a diagram on Timber Frame Headquarters site showing how to support posts and still have room on your walls for sips. 
LT40HD, 12' ext, 5105 JD tractor, Genie GTH5519 telehandler
M&K Timber Works

addicted

Great advice!
Thanks for your input guys.
What about exposure? I've seen a few pictures of foundation walls and slab poured that sits exposed through the winter. Is this a concern?

What about having the first floor deck on the foundation walls exposed throughout the winter? Some say the treated ply will do well while I've seen others say the corners will start to swell.

Timing for me is the issue. I won't be able to enclose the frame before winter. Getting the foundation in, and the deck on would allow me to raise the frame next spring. Is it worth the risk to have the Icf foundation wall or block with exterior rigid foam and basement slab exposed through the winter?
What has been your experience ?

Thanks
Rusty

Raider Bill

My ICF and floor underlayment was exposed to snow and rain for months with no effect. The blocks did get a slight chalking but a quick sweep with a broom took care of that before Stucco.
The First 70 years of childhood is always the hardest.

addicted

Thanks Bill
With the block and slab, my main concern would be frost heave or water getting into a spot between the two and freezing, causing a crack in the mortar or slab.
If I put the first floor deck on, my concern would be the snow, along with a freeze thaw cycle causing delamination of the ply.
How deep does the frost go in your neck of the woods?

Raider Bill

The First 70 years of childhood is always the hardest.

Don P

Frost has no power without water. If it is well drained then it will not heave. If you get ice under something there is no stopping it. Obviously we build through the winter before houses are heated, good drainage is the key.

I've had good luck with Advantek floor sheathing. I've pulled up many sheets of failed plywood but have never lost a sheet of this stuff. I do like to paint the floor with cheap oil based porch, garage floor or mismixed paint. Do not backfill a foundation until you have the floor on to hold the wall top in place.

Raider Bill

Quote from: Don P on May 11, 2017, 01:47:25 PM
Frost has no power without water. If it is well drained then it will not heave. If you get ice under something there is no stopping it. Obviously we build through the winter before houses are heated, good drainage is the key.

I've had good luck with Advantek floor sheathing. I've pulled up many sheets of failed plywood but have never lost a sheet of this stuff. I do like to paint the floor with cheap oil based porch, garage floor or mismixed paint. Do not backfill a foundation until you have the floor on to hold the wall top in place.

These were 3 of the many helpful tips you gave me 10 years ago when I built mine.
The First 70 years of childhood is always the hardest.

witterbound

My Advantek deck was exposed to the weather, and a lot of rain, for about two months.  I did paint it with returned and unused paint (that ended up pink when mixed) and tried to cover it with tarps to no avail.  It worried me, and showed some staining, but no buckling.  I personally would not want to have left it open to the weather all winter.

addicted

Thanks Don

Hey Witterbound, Where was your building site? Was it exposed to freezing temps?
Rusty

witterbound

Arkansas.  No freeZing temps before dry in.

MbfVA

Don P, what was the engineering concern you had with Superior?  Did you deal with John Cotton (plant in Amelia County)?

We are in Fluvanna and seriously considering Superior's Xi and maybe the AG above grade walls, tho' the cost is estimated at $130 per LF, $110 for the basement (9 ft ceilings).

I'm going to study the other systems mentioned herein, thanks for yours and everyone's comments.
www.ordinary.com (really)

Ljohnsaw

Quote from: MbfVA on May 29, 2017, 05:05:04 AM
We are in Fluvanna and seriously considering Superior's Xi and maybe the AG above grade walls, tho' the cost is estimated at $130 per LF, $110 for the basement (9 ft ceilings).

Is that the cost of just the blocks or does that include the concrete to fill them?  IIRC, my FasWall blocks were less than $10/24" length (8" high), or $5/ft.  So a 9' wall section would be 13½ blocks high = $67.50 plus concrete.

My 6' lift of 180 linear feet cost $2,000 for concrete (high strength "6-sack") and $420 for pumping.  The blocks were right about $8,000 for those.  So $10,420 for 1,080 sq-ft of wall area. (my labor was free ;) ).  That works out to $9.65/sq-ft.  So for a 9' wall, $86.83, filled.  There is rebar in there as well and my estimate for the rebar was $1,500 for this section but most of it I got for $0.10 on the dollar if not free.
John Sawicky

Just North-East of Sacramento...

SkyTrak 9038, Ford 545D FEL, Davis Little Monster backhoe, Case 16+4 Trencher, Home Built 42" capacity/36" cut Bandmill up to 54' long - using it all to build a timber frame cabin.

addicted

This is great information.
Thanks for the input guys.
Ljohnsaw , just to make sure we are comparing apples to apples, did the faswall company provide you with some engineering numbers? My question would be, is there a strength difference between a faswal pour vs an Icf pour because of the difference in the form that the concrete takes. I think I saw someone call the faswall shape a post and beam in an earlier post. In other words is there a difference in strength between a solid core of concrete inside an Icf vs the grid pattern of concrete inside a faswall type product?
Thanks
Rusty

Ljohnsaw

Yes, FasWall does provide engineering sheets.  Go to their web site and "request" the downloads.  You submit your information (email) and then you get an email with the links.  They will send you an email every now and then saying they can help you plan.  Nice and they don't get obnoxious with bothering you.  Their claim is they are approved by all  building departments. 

You can get lots of different strengths depending on the rebar grid.  The "normal" install calls for ½" #60 bar 24" OC vertically (every other hole) and 16" horizontally (every other course - but that is the closest you can get).  My engineer opted for higher strength since my walls are 12' tall (one corner is 14'-6").  I did 5/8" 12" OC vertically but still the ½" horizontal.  While you can walk on top of the dry stacked blocks, they don't provide any structural strength - it is all the concrete and rebar.  Also, the blocks are 12" wide and with 3" of insulation and ~2" side walls, the concrete is a little over 5" thick.  However, in areas where extra strength is needed, the insulation is removed (like under main posts or adjacent to door openings).
John Sawicky

Just North-East of Sacramento...

SkyTrak 9038, Ford 545D FEL, Davis Little Monster backhoe, Case 16+4 Trencher, Home Built 42" capacity/36" cut Bandmill up to 54' long - using it all to build a timber frame cabin.

MbfVA

Ljohnsaw, Superior builds the wall sections in their plant, and brings them to the job site, erects them one by one to form the basement wall, so other than the floor, no added concrete required.  Another nice feature is that no  traditional footing is required – they are set on several inches of gravel in the trench.  I think precompaction is required, not sure who does it.  We still have a lot to learn about it, but it is definitely one simple solution from the homeowner/builder standpoint. Cost, is another matter.

They also offer above ground walls, a bit more per ft than basement.

I've been told Superior does a lot of preliminary and engineering work for projects as well.  Rep said he'd be very involved (former Class A contractor himself).  A big factor for us is the fact that their VA plant is only a little over an hour away.

Turnkey is tempting, but we all have budgets.
www.ordinary.com (really)

Ljohnsaw

I forgot to factor in the footings.  That would bump the price about $6/foot (I split the cost of the footing between the two lifts - I paid about $12/foot for concrete and pumping - 12" thick, 24" wide).  I suppose it all comes down to what your time is worth.

So I ran the numbers a different way.  All the materials (FasWall and Concrete) and the labor (pumping) and divided by the wall length.  My walls are 10'8" under the porch, 12' for the majority of the basement (headroom of 10') with some dipping down to 14'8".  There is also the very large garage door and man door cut outs.  So I'm averaging the height to be 12'.  So the walls/foundation cost $144/linear foot and about $12/square foot.
John Sawicky

Just North-East of Sacramento...

SkyTrak 9038, Ford 545D FEL, Davis Little Monster backhoe, Case 16+4 Trencher, Home Built 42" capacity/36" cut Bandmill up to 54' long - using it all to build a timber frame cabin.

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