I haven't seen the system in person, but I see a few issues.

* the strength of the pieced- together polyethylene extrusions that are supposed to carry the drywall.

On a plumb block wall, the extrusions will work out. But on a typical poured foundation, this would be a difficult job.

Securing the two foot panels to the wall in compliance with Codes, and especially on a typical poured foundation will require lots more labour than with other methods. Each panel will have to be mechanically adhered. On the other hand, multiple 2x8 /2x10 or even 4x8 panels of traditional XPS can be attached with a fraction of the fasteners using strapping.

* the insulation value. This is expanded polystyrene, (EPS) not extruded polystyrene (XPS). EPS is ususally R4 per inch, yet ISF claims an R value of 10.44 over a poured 8" wall and R 11.08 over a 12" block wall. The manufacturer doesn't explain how the R value of the panels increases based on the substrate. There are also seams every two feet horizontally as well as the typical vertical seams. These are not shiplapped and should be taped.

You don't mention where you are located. But even the claimed R11.08 is well below recommended levels in most of the US and Canada. To reach those levels, you will have to put up a stud wall to the interior of the ISF panels.

XPS on basement walls, followed by traditional stud wall,
between which fiberglass insulation can be installed.

As alternatives, consider, Formular or traditional stud over XPS walls. (See photo.) Instead of wood, you can use lightweight non-structural steel.

Hello,

Its been a while since I posted my orginal question.

I would like to report i ended up using the Insofast system and could not have more pleased.

The whole process was so simple and Dean at insofast walked thru the whole process .

To answer the above question some of my poured foundation walls were out of plumb . I just used more glue to fill the void and make the walls plumb. Please show me a wood framed wall that is perfectly plumb. Wood studs are far from perfect.

Adhering the first few panels was a breeze. I just used a 1" shim off the floor and building the walls went up simple.I have 8' 10" walls. The glue that insofast recommend worked amazing. I could not remove these panels if I wanted too . I hung moisture resiant drywall and had no issues. At first I was a little reluctant. But the whole system went really well.

The Insofast panels are cheaper that tradtional framing,easier to work with and I have an r11 wall which is moisture resistant.

Overall , great modern product and I am glad I used the Insofast system in my basement.

Good to hear it worked out for you.

Nevertheless, the thermal value falls below the International Energy Conservation Code 2012 minimums in US climate zones 5, 6, 7, 8 and marine 4, the system material costs are 30%-40% greater than alternative systems, according to the Journal of Light Construction. As well, many jurisdictions require foamboards to be mechanically adhered to the interior basement wall. Indeed, to give the adhesive time to cure, mechanical attachment or bracing is specified by adhesive manufacturers.