North Georgia SCIPS house
Last Post 02 Feb 2021 05:30 PM by voldie. 38 Replies.
Author Messages
rlsmith017User is Offline
New Member
New Member
Send Private Message
Posts:35

--
21 Nov 2014 03:04 PM
We started construction late last month on our SCIPS home in north Georgia. This website has been an invaluable resource to me in planning my house. One way I can return the favor is by passing along what I learn in the process. I have started a blog to track the progress, which can be found here

The first two posts are now online: one with background information on the project and one with the excavation and footings. I hope this is of some value - I certainly learned a lot from Jim's blog on his Florida project. If you have questions I will try to answer them as time permits.

Roger
Roger
rlsmith017User is Offline
New Member
New Member
Send Private Message
Posts:35

--
22 Nov 2014 08:14 AM
The correct link is http://northgeorgiascipshouse.blogspot.com/
Roger
jonrUser is Offline
Senior Member
Senior Member
Send Private Message
Posts:5341

--
22 Nov 2014 12:22 PM
How much thermal bridging will there be between the footings and interior surfaces?
rlsmith017User is Offline
New Member
New Member
Send Private Message
Posts:35

--
22 Nov 2014 01:14 PM
jonr:
There shouldn't be much thermal bridging. We will use EPS underneath the slab and an EPS thermal expansion joint between the slab and the interior wythe of mortar.
Roger
jonrUser is Offline
Senior Member
Senior Member
Send Private Message
Posts:5341

--
22 Nov 2014 04:22 PM
So your interior side concrete wall directly contact the cold footings? Or can you set the wall on top of some high density horizontal foam and run rebar through it?
JellyUser is Offline
Veteran Member
Veteran Member
Send Private Message
Posts:1017

--
22 Nov 2014 09:43 PM
looks like the footing will be deep underground, so thermal bridging wouldn't be as much of a concern as wicking of moisture. But the fastfoot may take care of that.

Roger, I've never seen a foundation like that - very interesting. So I assume you excavated to the level where the fastfoot is placed, so it is on undisturbed soil?
rlsmith017User is Offline
New Member
New Member
Send Private Message
Posts:35

--
22 Nov 2014 10:49 PM
jonr
Yes, the interior side concrete will directly contact the footings - I don't think the engineer would buy replacing mortar with foam.
Roger
rlsmith017User is Offline
New Member
New Member
Send Private Message
Posts:35

--
22 Nov 2014 10:50 PM
Jelly:
The FastFoot is designed to prevent wicking. And yes, it was indeed excavated so that the footing was on undisturbed soil.
Roger
AltonUser is Offline
Veteran Member
Veteran Member
Send Private Message
Posts:2157

--
22 Nov 2014 11:02 PM
The waterproofing on the wall will come down and overlap the FAST FOOT membrane and footer.  This should direct the water to the foundation drain.  This should greatly reduce the footer and wall's ability to transmit water vapor to the basement.
Residential Designer &
Construction Technology Consultant -- E-mail: Alton at Auburn dot Edu Use email format with @ and period .
334 826-3979
JellyUser is Offline
Veteran Member
Veteran Member
Send Private Message
Posts:1017

--
23 Nov 2014 11:27 PM
I like it. Looking forward to following the project
jonrUser is Offline
Senior Member
Senior Member
Send Private Message
Posts:5341

--
24 Nov 2014 10:41 AM
looks like the footing will be deep underground, so thermal bridging wouldn't be as much of a concern...
To me it looks like at least one side of the building will have footers close to grade level. So heat/cold travels down the exterior wall, across the footing and then back up the interior wall. Berming soil (or some better insulator) against the lower portion of the exterior walls would help some (by creating a longer path).

I'd consider painting a stripe of Drylok on the top of the footings to further block water/moisture wicking up the interior walls.
rlsmith017User is Offline
New Member
New Member
Send Private Message
Posts:35

--
05 Dec 2014 11:01 AM
Two new posts have been added: a very short one with additional thoughts on using the FastFoot system plus one on the logistics of using SCIPS.

http://northgeorgiascipshouse.blogspot.com/
Roger
rlsmith017User is Offline
New Member
New Member
Send Private Message
Posts:35

--
11 Dec 2014 09:27 PM
A new post is now online, with the first week of placing panels.

http://northgeorgiascipshouse.blogspot.com/
Roger
newbostonconstUser is Online
Advanced Member
Advanced Member
Send Private Message
Posts:736

--
13 Dec 2014 05:58 AM
Very good info. ...thanks for sharing
"Never argue with an idiot. They will only bring you down to their level and beat you with experience." George Carlins
GeorgiaTomUser is Offline
Basic Member
Basic Member
Send Private Message
Posts:159

--
19 Dec 2014 07:10 AM
looking at the blog pictures, was wondering about the concrete coverage on the epoxied dowels, will only have 3/4" plaster cover? It doesn't seem like enough coverage
jonrUser is Offline
Senior Member
Senior Member
Send Private Message
Posts:5341

--
19 Dec 2014 08:49 AM
Good question. With the amount of moisture in the lower wall area, I would think that galvanized rebar, more cover, an admixture or perhaps epoxy rebar would be necessary to prevent long term corrosion. Rebar on the interior side would be drier.
JellyUser is Offline
Veteran Member
Veteran Member
Send Private Message
Posts:1017

--
19 Dec 2014 09:32 AM
GeorgiaTom, was your concern about resistance to shear or about corrosion?
GeorgiaTomUser is Offline
Basic Member
Basic Member
Send Private Message
Posts:159

--
21 Dec 2014 08:24 AM
Jelly : concern is both corrosion and shear, it does not look like there is sufficient embedment (code is minimum 1-1/2 cover above ground 3" below ground )for corrosion in any direction. it looks like a thin veneer covering so I am also wondering what is holding it to the footer and keeping it from moving around
AltonUser is Offline
Veteran Member
Veteran Member
Send Private Message
Posts:2157

--
21 Dec 2014 02:21 PM
Although the blog pictures may not show it, there will be a row of rebar dowels on each side of the wall.  Using a double row of dowels may be one reason for the light embedment.

I think it would be better to use non-rusting basalt rebar, especially if the embedment is thin.  Basalt rope might even be a better idea for the area of the wall above the basalt rebar dowels.
Residential Designer &
Construction Technology Consultant -- E-mail: Alton at Auburn dot Edu Use email format with @ and period .
334 826-3979
LbearUser is Offline
Veteran Member
Veteran Member
Send Private Message
Posts:2740
Avatar

--
21 Dec 2014 08:03 PM
They were recently renovating a 100-year old masonry courthouse in the area and what they discovered is that the building suffered major rebar corrosion which began to compromise the buildings structural integrity. Mind you this was for a Zone 4B area (high desert) so precipitation is very low.

The engineers stated that problem was that the exterior of the masonry building was NOT waterproofed and when it rained the concrete absorbed the moisture and it began to corrode the rebar.

Alcatraz has been corroding from the inside out for decades because the moisture ridden salt air got through the concrete and the rebar began to corrode.

Being this home is in Georgia (humid/wet) climate, will they waterproof the exterior concrete walls?
GeorgiaTomUser is Offline
Basic Member
Basic Member
Send Private Message
Posts:159

--
21 Dec 2014 08:13 PM
light embedment? sounds like a double row of inferior embedment
jonrUser is Offline
Senior Member
Senior Member
Send Private Message
Posts:5341

--
21 Dec 2014 08:21 PM
I expect that rain water will come down the walls and enter the inevitable crack between the footing and the stucco/wall. Standard rebar in this joint area might eventually rust no matter what the cover is.
AltonUser is Offline
Veteran Member
Veteran Member
Send Private Message
Posts:2157

--
21 Dec 2014 09:27 PM

SCIPs use either sprayed concrete or high PSI structural mortar to carry the loads.  Stucco can be used but only for a finish.  In this case, Carmelo structural mortar will be used to embed the rebar dowels and to cover the galvanized wire mesh.  Rebar can be countersunk back into the EPS to gain more embedment.  Waterproofing will also be applied.  The wall/footer joint will be below the bottom of the basement slab.  Locating the slab above the joint should allow it to brace the wall even if the rebar dowels do shear.
Residential Designer &
Construction Technology Consultant -- E-mail: Alton at Auburn dot Edu Use email format with @ and period .
334 826-3979
GeorgiaTomUser is Offline
Basic Member
Basic Member
Send Private Message
Posts:159

--
21 Dec 2014 09:44 PM
the rebar can be countersunk into EPS, not sure what value rebar into EPS has, but that's not what the picture showed anyway. There is no positive connection of the wall to the footing as far as I can determine.
AltonUser is Offline
Veteran Member
Veteran Member
Send Private Message
Posts:2157

--
21 Dec 2014 11:02 PM

Inside and outside rows of rebar dowels are located between the galvanized wire mesh and the corrugated EPS.  The location of the dowels are staggered on 16" centers.  Both rows of dowels are wired to the galvanized mesh.  Countersinking the dowels into the EPS requires EPS to be removed to create a void behind each dowel so that it can be filled with structural mortar.   Spraying structural mortar on the installed panels creates a bond with the wire mesh, dowels and EPS.  This creates a positive connection between the footer and panel. 

Residential Designer &
Construction Technology Consultant -- E-mail: Alton at Auburn dot Edu Use email format with @ and period .
334 826-3979
rlsmith017User is Offline
New Member
New Member
Send Private Message
Posts:35

--
22 Dec 2014 12:32 AM
I have been on the road and haven't had a chance to join the discussion. For those who may have not read the blog, Alton has been involved in the project since the very beginning and is very familiar with most of the details.

A couple of points to add:
1. The Carmelo mortar is rated at 4000 psi @ 28 days. Based on the EOR's experience I believe he said the long-term value is more like 7000 psi. This is a far different material than regular concrete, plaster or stucco.
2. A finish on concrete or mortar increases resistance to water penetration. Since the mortar can be finished all the way down to the footer we should avoid many problems associated with rough concrete in subsurface applications.
3. The mortar is the last line of defense against moisture. We designed to include a waterproof membrane which will overlap the fastfoot material and be glued to it. The mortar will be radiused from the vertical wall to the top of the footer, directing water away from the wall. The fill will be washed gravel with 1 foot of clay at the top. One of the advantages of the fastfoot system is that the drains can be lower than the top of the footer, rather than roughly at the same level like many applications.
4. The early pictures showed the rebar in contact with the EPS. After the panels are up but before the mortar is applied the EPS is burned out to provide room for the mortar to completely surround the rebar.

Hopefully this clears up a little of the confusion on the subject.
Roger
rlsmith017User is Offline
New Member
New Member
Send Private Message
Posts:35

--
22 Dec 2014 10:39 AM
One additional question that I missed earlier: the entire exterior will be waterproofed, not just the below-grade portions. We are planning on using an elastomeric finish for the color and waterproofing above-grade.
Roger
GeorgiaTomUser is Offline
Basic Member
Basic Member
Send Private Message
Posts:159

--
23 Dec 2014 06:33 AM
still trying to wrap my head around a plaster coating inside and out having any structural capabilities - how is it bonded to the foam? since the foam is below grade is it treated against termites
AltonUser is Offline
Veteran Member
Veteran Member
Send Private Message
Posts:2157

--
23 Dec 2014 09:54 AM
See http://gulfconcretechnology.com/ind...gory_id=22     for mortar specs.

The panels as shipped are not treated to kill termites.  The high PSI structural mortar on both sides of the wall should deter termites.  No structural wood in wall for termites to eat.

See http://gulfconcretechnology.com/  for short video.
Residential Designer &
Construction Technology Consultant -- E-mail: Alton at Auburn dot Edu Use email format with @ and period .
334 826-3979
rlsmith017User is Offline
New Member
New Member
Send Private Message
Posts:35

--
23 Dec 2014 10:03 AM
Although Alton is correct that there should be no termite danger we will treat for termites as if it were a wood house. I'm concerned about organic material around the foundation attracting termites so although there is VERY limited wood in the structure we will take the additional precautions.
Roger
rlsmith017User is Offline
New Member
New Member
Send Private Message
Posts:35

--
23 Dec 2014 10:15 AM
GeorgiaTom:

I think this should answer your questions about the structural properties of the panels.

http://www.drjengineering.org/system/files/drj/ter/node/69/ter_1202_12asd_gct_insulated_concrete_panel_building_system.pdf

We are using the thickest panels, the PSM 240 panels.
Roger
jonrUser is Offline
Senior Member
Senior Member
Send Private Message
Posts:5341

--
23 Dec 2014 12:38 PM
I expect that underground will be damp enough for corrosion no matter what you do with finishes or membranes. Given the minimal increase in cost, I'd use epoxy coated rebar as cheap long-term corrosion insurance in a SCIP house.
LbearUser is Offline
Veteran Member
Veteran Member
Send Private Message
Posts:2740
Avatar

--
23 Dec 2014 01:03 PM
Posted By jonr on 23 Dec 2014 12:38 PM
I expect that underground will be damp enough for corrosion no matter what you do with finishes or membranes. Given the minimal increase in cost, I'd use epoxy coated rebar as cheap long-term corrosion insurance in a SCIP house.

If you are talking about vapor diffusion and the permeability of how much water vapor will travel through the stem wall/basement wall, I would be interested to see the calcs on that.

If the ground is saturated with moisture, water vapor can still make its way through since EPS is permeable and its permeability is based on its thickness. That is why EPS sitting in a pool of water for days/weeks/months will take on water and begin to get become water saturated.

This will surely be climate dependent. In the desert southwest I wouldn't worry about it but in the humid southeast it would be more of a concern.

I reference Alcatraz again because the prison walls began to fall apart from the INSIDE out. The corroding rebar within the concrete mass wall caused the concrete to crumble. While this was an extreme environment (next to ocean with salt air 24/7), it served as a lesson when it comes to when epoxy/corrosion resistant rebar should be used. 
AltonUser is Offline
Veteran Member
Veteran Member
Send Private Message
Posts:2157

--
23 Dec 2014 05:08 PM

Epoxy coated rebar can be compromised during installation.  Once the coating is scratched, corrosion can continue under the coated part.  Galvanized rebar might cost more but would not be as easily compromised as epoxy coated rebar.  Basalt rebar is stronger, lighter and not subject to corrosion.
 
I would not recommend epoxy coated rebar for this application since the wire mesh can scratch the coating.

Ideally, I would like to see the rebar dowels outside the mesh.  This would avoid having to raise the panel to slid it down over the dowels.  However, more mortar would be required but the labor savings might offset the extra cost of mortar.

Residential Designer &
Construction Technology Consultant -- E-mail: Alton at Auburn dot Edu Use email format with @ and period .
334 826-3979
rlsmith017User is Offline
New Member
New Member
Send Private Message
Posts:35

--
23 Mar 2015 09:42 PM
There is a new post on the blog, updating progress through mid-December. It's only a little late. . .

http://northgeorgiascipshouse.blogspot.com
Roger
guyprotectionUser is Offline
New Member
New Member
Send Private Message
Posts:2

--
23 Apr 2015 10:20 PM
thanks for the good info

LbearUser is Offline
Veteran Member
Veteran Member
Send Private Message
Posts:2740
Avatar

--
23 Apr 2015 11:44 PM
Posted By rlsmith017 on 23 Mar 2015 09:42 PM
There is a new post on the blog, updating progress through mid-December. It's only a little late. . .

http://northgeorgiascipshouse.blogspot.com

Thanks for the blog, very informative.

Would you say the total wall costs for everything came in at around $25 per square foot of wall space?


rlsmith017User is Offline
New Member
New Member
Send Private Message
Posts:35

--
24 Apr 2015 07:46 AM
I've had a couple of inquiries about the cost of the wall system. It's still too early to see if I will meet the original estimate of $25 per square foot. The fact that the house is three levels (basement, main floor and loft, with poured concrete floors on all levels, may push that figure upward. Once the envelope is finished the builder and I will try to tease out the $/sf figure for the walls. Separating the cost of the SCIPS walls from the cost of the SCIPS roof may be a challenge.

We are still a couple of months from that point.
Roger
voldieUser is Offline
New Member
New Member
Send Private Message
Posts:8

--
02 Feb 2021 05:30 PM
Bumping this thread. How did the project go? I am assuming that you must have been happily living in your house by now.


---
Active Forums 4.1