Structural Concrete Insulated Panel SCIP
Last Post 01 Feb 2021 05:42 AM by voldie. 315 Replies.
Printer Friendly
Sort:
PrevPrev NextNext
You are not authorized to post a reply.
Page 15 of 16 << < 1213141516 > >>
Author Messages Not Resolved
jrobxUser is Offline
New Member
New Member
Send Private Message
Posts:11

--
07 Sep 2014 09:04 AM
Hi Cath,

I used a BASF product called SonoGuard.  It goes down in two phases a base coat that stays relatively soft and a topcoat that can stand up to traffic.  It's intended as a coating for parking structures so it's incredibly tough. I used a 3100 psi power washer to remove some concrete overspray and it didn't touch the coating even at point blank range.  BASF makes a different formulation for sloped surfaces but it's the same price (~$180 for 5 gal)



It's been on the roof since Feb and it immediately stopped water intrusion at the roof surface.  I still had issues at the roof wall joint thanks to Mr Bill but that has been solved by a truly professional concrete company I brought in.

jim


jrobxUser is Offline
New Member
New Member
Send Private Message
Posts:11

--
07 Sep 2014 09:40 AM
I've not contributed to this forum for many months.  Much discussion on thermal and heat transfer properties of SCIP.  So I present the following empirical data.  The two thermal images attached were made with a FLIR IR camera.

******Disclaimer*****
While this camera has an built in self calibration feature it has not been independently calibrated by a metrology lab.  Absolute readings should be treated with caution.  Relative readings (differences in temperature) are probably reasonably accurate.
*****End Disclaimer***

The pictures are of the same spot on inner and outer surface of a South facing SCIP wall which uses 6 inch EPS.  The outer Wythe is 2 inches of shotcrete plus a 1 inch of gunite overlay.  The inner Wythe is 1.5 inches of shotcrete.  Only a dehumidifier is running on the inside.  Pictures were taken around 1400 on 4 Sept in P.C. Florida.  Sunny skies, outside air temperature 93°F, Inside air temperature 85°F. 



The outside wall is bare concrete so is not reflecting as well as it will when it's finished (white).  The roof directly above is finished (white) and was showing a surface temperature of 99°F at the same time.  I'm currently re-evaluating my inside insulation strategy.


jonrUser is Offline
Senior Member
Senior Member
Send Private Message
Posts:5341

--
07 Sep 2014 10:31 AM
More labeling on the pictures would be helpful. What is your conclusion from them?


jrobxUser is Offline
New Member
New Member
Send Private Message
Posts:11

--
07 Sep 2014 11:30 AM
Sorry, couldn't figure out how to attach labels.  The image on the left is the outside solar heated surface, image on the right is the same spot on the inside of the building.  This is a visible light picture of the same area taken several weeks earlier.  The IR images are centered six feet below the roof line near the middle of this image.



My conclusion is the inside wall is going to be much warmer in the summertime than I expected.  The emissivity of bare concrete implies that at 86°F that wall can pump as much as 380 Watts/M^2 if it's radiating into a black body.   The power transfer into an air conditioned space will be less but still significant. 

I think at a minimum I'm going to have to add insulation to the South wall.  The bare furring on that wall is visible in the right image of the original post.

Interested in any opinions on the subject.

jim


jonrUser is Offline
Senior Member
Senior Member
Send Private Message
Posts:5341

--
07 Sep 2014 12:00 PM
The interior wall is at 87.3F mostly because the interior is at 85F. But these figures are not what you want to use when determining btu transfer into the interior when using AC.

For example, even a box with 12" of insulation and 100F on the exterior will eventually reach 100F on the interior. But so what.

White paint is going to save quite a bit (when the sun is shining), but shade from overhangs or trees is even better (plus they work with windows).


jrobxUser is Offline
New Member
New Member
Send Private Message
Posts:11

--
07 Sep 2014 01:02 PM
You are of course correct about any system eventually reaching equilibrium.

My problem is I can't prove my heat transfer is from air infiltration or radiant heating. 

My initial thought was that the window and door bucks weren't sealed properly and we were exchanging air with the outside.  We have been eliminating those air exchange sources and after the furring lumber dried out we were able to keep the relative humidity below 55% initially using portable air conditioners then only a dehumidifier.  The inside temperature however continues to follow the outside air temperature with perhaps an 8°F offset over a fairly short time constant.

The windows are being wrapped with a vapor barrier/architectural foam treatment primarily to address waterproofing but this will also completely eliminate them as a source of air exchange.  I'll still have the doors as a possible source. 

My immediate dilemma is the dry wallers are ready to start as soon as the window crew is done.  I'll have to decide on the additional insulation before they start and before the doors can be vapor sealed.  I'm only considering the sun facing wall and a reflective insulation product tacked to the tops of the studs.

jim


jonrUser is Offline
Senior Member
Senior Member
Send Private Message
Posts:5341

--
07 Sep 2014 01:39 PM
I'd use gaskets (not caulk or spray foam) as much as possible and then use a blower door to test for air infiltration. I'd think about the thermal bridging caused by the stucco on the window/door edges. I wouldn't mess with radiant barriers or adding more insulation to the center wall areas (assuming no significant thermal bridging there).


FBBPUser is Offline
Veteran Member
Veteran Member
Send Private Message
Posts:1215

--
07 Sep 2014 01:48 PM
If I'm reading the pictures right, the temperature gradient matches the colour of the the concrete. Red in the darker areas, yellow in the whiter areas. How are the inner and outer wythes connected?


jrobxUser is Offline
New Member
New Member
Send Private Message
Posts:11

--
07 Sep 2014 01:57 PM
The visible light picture was taken immediately after the gunite cover was applied so it was still expelling and incorporating water.  It doesn't have the same color variations today.

Wythes are connected with Galvanized Z-trusses on 6 inch centers.  I looked for evidence of heat transfer by conduction especially on the inner Wythe but can't see anything at six inch intervals.  The inner Wythe is thermally uniform, shows random variations of a few tenths of degrees.   A North facing wall that never sees sunlight and another interior SCIP wall that isn't exposed to the outside in anyway are about two degrees cooler.  This supports jonr's contention that the inner Wyeth is being heated mostly by inside air not by heat transfer from the outer Wythe.  His argument makes sense in light of the other evidence I have.

jim


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

--
07 Sep 2014 02:06 PM
Posted By jrobx on 07 Sep 2014 11:30 AM


My conclusion is the inside wall is going to be much warmer in the summertime than I expected.  The emissivity of bare concrete implies that at 86°F that wall can pump as much as 380 Watts/M^2 if it's radiating into a black body.   The power transfer into an air conditioned space will be less but still significant. 

I think at a minimum I'm going to have to add insulation to the South wall.  The bare furring on that wall is visible in the right image of the original post.

Interested in any opinions on the subject.

jim

On you SCIP core, do the steel rebar/wire trusses transition from the interior side, then through the EPS foam, and finally exit out the exterior side? I know this is then covered with ShotCrete. Could this type of design create a thermal bridge from the outside to the inside due to the steel trusses that are not thermally broken?

The SCIPs that I have seen have these steel wire trusses every 4-6 inches and this would seem to be a thermal bridge.


cathsandUser is Offline
New Member
New Member
Send Private Message
Posts:43

--
13 Sep 2014 10:37 PM
Hey Jim, the house is looking great! I tried posting a pic of mine, but can't from my iPad. Do you suppose your gunite crew could come to Fayetteville.


cathsandUser is Offline
New Member
New Member
Send Private Message
Posts:43

--
13 Sep 2014 10:40 PM
As to thermal bridging, personally I think we are overthinking that. With 10 inches of foam sandwiched in there, you might have some conduction, but it is far outweighed by your insulation. I wouldn't insulate further.


jrobxUser is Offline
New Member
New Member
Send Private Message
Posts:11

--
14 Sep 2014 06:23 AM
Posted By cathsand on 13 Sep 2014 10:40 PM
As to thermal bridging, personally I think we are overthinking that. With 10 inches of foam sandwiched in there, you might have some conduction, but it is far outweighed by your insulation. I wouldn't insulate further.

The lack of thermal variation on the inner wall suggests that is the case.  I'll send you contact info for Prestige.


fun2driveUser is Offline
New Member
New Member
Send Private Message
Posts:68

--
14 Sep 2014 10:47 PM
Read your entire blog. I have learned a great deal here and reading the blog too.
Thanks for posting...


slenzenUser is Offline
Basic Member
Basic Member
Send Private Message
Posts:434

--
28 Oct 2014 09:24 AM
glad to see some updates! Was intrigued by this build!

Knowing what you know now, would you do it all over again? What would you do different? (edit) after reading your blog updates, how do you not have any F-bombs plastered all over it! LOL congrats on the patience and perserverence!!!


jrobxUser is Offline
New Member
New Member
Send Private Message
Posts:11

--
30 Oct 2014 07:12 AM
Posted By slenzen on 28 Oct 2014 09:24 AM
glad to see some updates! Was intrigued by this build!

Knowing what you know now, would you do it all over again? What would you do different? (edit) after reading your blog updates, how do you not have any F-bombs plastered all over it! LOL congrats on the patience and perserverence!!!
There are hundreds of things I'd have done differently which I'm compiling for the final Post in the blog. 

I guess the biggest would be to not use SCIP everywhere.  It just isn't practical on overhead surfaces.  I'd go with my initial idea of a conventional steel beam skeleton with a steel deck floor and roof system.  I'd also not attempt a non mainstream construction from 1500 miles away.



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

--
31 Oct 2014 02:03 AM
Your blog stated:

"What do you do when your interior walls look like a North Korean prison camp?

As I have previously mentioned the finish left me by the original builder/architect was not what I expected.  His original plan which was part of his basis for the Guaranteed Maximum Price Contract was that the inner  concrete surfaces would be regular enough to finish with common plaster that would yield a surface as smooth as drywall which could then be painted or finished to taste at low cost.  The reality was far different."


The Gunite/Shotcrete looked really bad and the interior and exterior finish they left behind was tough on the eyes. It looked like it had started to flake off and exposed the metal rebar. While you state it was "cosmetic" in nature, it sure looks like it cost a fortune to fix these mistakes. Care to share how much $ was spent fixing these issues?


There seemed to be a lot of water intrusion problems with the SCIPs. If you had to do it again would you choose SCIPs again or maybe ICF, tilt-up concrete?






jrobxUser is Offline
New Member
New Member
Send Private Message
Posts:11

--
31 Oct 2014 06:57 AM
Posted By Lbear on 31 Oct 2014 02:03 AM
Your blog stated:

"What do you do when your interior walls look like a North Korean prison camp?

As I have previously mentioned the finish left me by the original builder/architect was not what I expected.  His original plan which was part of his basis for the Guaranteed Maximum Price Contract was that the inner  concrete surfaces would be regular enough to finish with common plaster that would yield a surface as smooth as drywall which could then be painted or finished to taste at low cost.  The reality was far different."


The Gunite/Shotcrete looked really bad and the interior and exterior finish they left behind was tough on the eyes. It looked like it had started to flake off and exposed the metal rebar. While you state it was "cosmetic" in nature, it sure looks like it cost a fortune to fix these mistakes. Care to share how much $ was spent fixing these issues?


There seemed to be a lot of water intrusion problems with the SCIPs. If you had to do it again would you choose SCIPs again or maybe ICF, tilt-up concrete?




The interior cosmetics were corrected by furring and drywall (post 42)

I'm pretty sure I never said I had exposed "rebar" in the blog  if I did that was a mistake. I did have exposed mesh but that was almost exclusively around window and door bucks (Post 38).  The shotcrete itself never flaked it was the "brown coat" that the builder used to try to fix the cosmetics on the exterior that did.

The water intrusion problems weren't specifically due to SCIP it was the result of not adequately considering water intrusion paths during design and construction of roof wall joints.  The worst offender was the acute angled (34° pitch) facet at the North wall.  To that add my decision on placement of 8 inch deep windows midway in a wall system that is up to 14 inches thick.  I'd have had all the same issues with ICF and I never concidered tilt up.  All if this could have been avoided had the joints and wall penetrations been designed and constructed with water intrusion in mind.

Not considering schedule impacts fixing all of the above cost about $120K.  As I said before I'd do things a lot differently if I was starting over.



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

--
31 Oct 2014 11:15 AM
Posted By jrobx on 31 Oct 2014 06:57 AM

Not considering schedule impacts fixing all of the above cost about $120K.  As I said before I'd do things a lot differently if I was starting over.


Complete SCIP construction costs were $120k or just the cosmetic fixes?


jonrUser is Offline
Senior Member
Senior Member
Send Private Message
Posts:5341

--
31 Oct 2014 12:05 PM
I guess the biggest would be to not use SCIP everywhere.  It just isn't practical on overhead surfaces.


It will be interesting to hear more. Most SCIPs homes don't have a problem with overhead surfaces.


You are not authorized to post a reply.
Page 15 of 16 << < 1213141516 > >>


Active Forums 4.1
Membership Membership: Latest New User Latest: hudson2000 New Today New Today: 0 New Yesterday New Yesterday: 2 User Count Overall: 34707
People Online People Online: Visitors Visitors: 112 Members Members: 0 Total Total: 112
Copyright 2011 by BuildCentral, Inc.   Terms Of Use  Privacy Statement