In the climate of the Netherlands thermall mass in buildings is very usefull.

Is there experience to add extra mass to SIP walls on the inside of the house? Like clay plaster (5cm) or sprayed/shot concrete. (8cm)

Dat heb ik nog nooit gezien, maar alles is mogelijk... (met genoeg geld bedoel ik... ;-) )

ICF is waarshijnlijk goedkoper en beter (veel sterker) dan 8cm "shot-crete" op de binnenkant van een SIP. Maar ken ik niet wat het de bouwstoffen kosten zijn in NL. (Klei en zand zijn waarschijnlijk zeer goedkoop, he'? ;-) )

A monolithic concrete slab works well in my home, it stays a constant 72 degrees

Posted By cmkavala on 28 Sep 2012 06:15 PM
A monolithic concrete slab works well in my home, it stays a constant 72 degrees

Chris, did you insulate your slab-on-grade or just place it on raw earth?

Dana is Dutch or has a good translator.......

Posted By MikeSolar on 28 Sep 2012 07:02 PM
Dana is Dutch or has a good translator.......

Dana is waarschijnlijk met behulp van translate google

Lbear , just earth

Posted By cmkavala on 28 Sep 2012 07:46 PM

Posted By MikeSolar on 28 Sep 2012 07:02 PM
Dana is Dutch or has a good translator.......

Dana is waarschijnlijk met behulp van translate google

Alletwee fout! 

Ik bin zeker amerikaans maar woonde ik een tijdje in nederland geweest. (Maar niet sinds acht en negentig).  Mijn grijp van de taal wordt nog steed zwakker, maar herinner ik nog een word of tien. (Gellukkig, he'? Of mischien niet... )

Anders van SIP of ICF, heb je ooit van SCIP gehoord?  (Google het maar!)

Wow ik ben onder de indruk! Ik ben afhankelijk van google om mij zien als een Nederlandse genie.

If you want to spray concrete on it, then SCIPs may be a better choice.

http://scipresources.com/materials/

But also note that passive, internal thermal mass is only helpful if you are willing to tolerate temperature variations.

ICF is no option then the thermal mass is isolated or you have remove the EPS on the inside after the concrete is cured.

With SCIP's Don't you have al lot of thermal bridges? By the edges of window and door frames and trough the steel truss inside the EPS foam.

But also note that passive, internal thermal mass is only helpful if you are willing to tolerate temperature variations.

In the Netherlands an airconditioning in houses is very rare. So temperature variations are very normal. In stead of add thermal mass you can also place an airco, but that's not eco friendly.

Posted By Tjibbe Rijpma on 29 Sep 2012 04:33 AM
ICF is no option then the thermal mass is isolated or you have remove the EPS on the inside after the concrete is cured.

With SCIP's Don't you have al lot of thermal bridges? By the edges of window and door frames and trough the steel truss inside the EPS foam.

SCIPs with metal trusses within the panel did suffer from severe thermal bridging. ORNL tests show the manufacturer claimed R-20 wall dropped to R-8 due to the thermal bridging of the metal trusses within the SCIP.

ORNL TEST

Supposedly there is a SCIP that uses plastic trusses in the panel, this would eliminate the thermal bridging problem with metal trusses.

A plastic connection between the inner and outer steel reinforcement. Does it exists and is it tested for a couple of years?

If it does you have design a the connection to the outer and inner concrete by a window opening without a thermal bridge.

But how expensive could a standard sip with shot concrete be? I think a normal OSB sip also needs a gipsy board on the inside for fire protection and for aesthetic reasons some plaster is welcome. A shot concrete layer is both.  And i read somewhere that the maximum wall height of SIPs is 3 meter. I prefer a higher living room and think this is possible with a reinforced shot concrete layer on the inside. To avoid the basement will float i also needs mass, but it is cheaper to add this on de floors.

I found a plastic one (zie pdf in attachment), but on their website I can't find a good window detail drawing.

ORNL tested a steel mesh SCIP with 2" of foam and got a reduction from R10 to R7.6. Not at all a R20 to R8 drop and easily made up for by another 1/2" of foam.

All wall options are effected by thermal bridging

If for some reason I wanted to attach concrete to the inside of SIP walls, I would buy or make precast panels or blocks and screw them to the SIP (with the floor bearing the weight). But in most cases, I don't think internal thermal mass is worth the downsides.

Posted By cmkavala on 28 Sep 2012 10:20 PM
Wow ik ben onder de indruk! Ik ben afhankelijk van google om mij zien als een Nederlandse genie.

stop showing off

Posted By Tjibbe Rijpma on 29 Sep 2012 04:33 AM
ICF is no option then the thermal mass is isolated or you have remove the EPS on the inside after the concrete is cured.

With SCIP's Don't you have al lot of thermal bridges? By the edges of window and door frames and trough the steel truss inside the EPS foam.

With ICF using 2x thicker insulation on the exterior side than on the interior is effective.  While there is still some isolation from the interior, the thermal mass is still mostly inside the thermal boundary of building, and it keeps the interior wall surface very stable. The isolation of the interior side foam keeps the mass from being useful for moderating heat gains & losses from windows, but it is still an important contributor to the performance of the building.  (You are probably not designing a lot of passive-solar gain into the house either, given the short winter days and winter cloud cover in a NL climate.)

In order to shot-crete the interior a SIP you would have to attach some sort of metal mesh anchored to the inner skin of the SIP to guarantee that it bonds well and won't separate over decades of temperature & humidity cycling.  If you want the thermal mass to be substantial, and entirely inside the insulation it may be cheaper and better to build a concrete wall and add sheets of EPS to the exterior. Starting with a SIP and adding concrete seems like it would be more expensive, and provide less thermal mass.  (But I don't know how expensive building with concrete is for you.  IIRC there is at least some limestone in the area around Maastricht, but I suspect most cement & stone material is imported.)

As others have mentioned, there are multiple approaches to SCIP that attempt to reduce the thermal bridging.  In warmer climates (where SCIP construction is more common) the thermal bridging is lesser importance than the thermal mass, and not all versions will be ideal for NL.  What U-factors were you hoping to achieve?

Posted By jonr on 29 Sep 2012 10:37 AM
If for some reason I wanted to attach concrete to the inside of SIP walls, I would buy or make precast panels or blocks and screw them to the SIP (with the floor bearing the weight). But in most cases, I don't think internal thermal mass is worth the downsides.

Other than temperature swings, what is the downside of interior thermal mass?

Wrong LBear. The ORNL test was of Dow's T-Mass wall system, concrete inside a 2" XPS sheath, whiich it ultimately sold. So thermal bridging degraded R10 to R8. The R20 figure claimed by Dow was its mass-enhanced equivalent R value.