Hello, DIY ICF construction of a small (500 sq feet) rectangular house in a small town in Canada. Due to multiple delays we've hit November and are just starting stacking ICF. We're using AMVIC blocks - building on footings that are on a clear stone base. Questions 1) What is the best way to keep snow/ ice out of ICF forms while building? Tarps? Concrete blankets? Caps that we make out of plywood? Would appreciate tips/ guidance/ pictures from anyone who has done this before - we're unfortunately expecting a few snowy nights 2) It likely be -5 to -10 degrees Celsius when the pour is done (experienced crew here). We will be setting anchor bolts that stick out. Do we need to worry about the concrete at the top freezing? Whats the best way to cover the top without interfering with the anchor bolts? 3) One of the walls (due to grade) is 12ft high from subgrade. Our supplier here does not have bracing extensions for their 10ft wall bracing system (plumwall) - can anyone please recommend additional DIY bracing we should put in place to be safe - will take any and all guidance and pictures on additional recommended bracing 4) Any other winter considerations? Thank you

Plastic on top should be good to keep snow out. The concrete would be made with hot water. I would use a mid range water reducer in a two slump mix. Keep the top uncovered as long as possible. Should be ok. Pour in as many lifts as possible at least 4 for the 12 ft section. As far as the bracing' make T or L extensions out of 2x4's for the bottom of the wall and set the bracing on those screw the 2x's into the webs . You'll have to do the same for the adjustment legs make them 8 ft long with the base plates screwed into the 2x's and the top of the 2x's screwed thru the holes in the legs. Should be plenty strong.

Thank you very much - appreciate the guidance!

"Keep the top uncovered as long as possible" - may I ask what is the reason to keep it uncovered as long as possible?

Primary way to dry the wall. Takes forever depending on drying thru the cracks in the icf

Be sure to insulate any exposed concrete after placement. If it is plus/minus a few degrees of freezing, dimensional lumber should suffice to trap the heat generated by the curing process. If is gets colder, insulated tarps or rigid insulation may be needed. You do not need to heat/horde the entire wall - the ICF panels will trap the heat inside, but be sure to protect sills of W&D bucks. Between days, plastic, lumber, etc will work to protect the inside of the wall and interlock from snow, freezing rain, etc.

Also, you should absolutely keep the concrete covered as long as possible. Concrete does not "dry out" it cures. This is a chemical reaction (hence the heat generated during the curing process). This process will continue until all water has been used up. The longer the water is available, the longer the concrete curing will continue, which will often result in a final strength surpassing the original design strength. Ideal curing is under water, which will continue the cure process for up to 7 years (according to an architect I know).

The product manufacturing specs or site engineering will typical list a min time that the concrete must be kept above freezing (typically between 48hrs and 7days). Be sure to keep protection in place to trap the heat within the mix for the necessary amount of time.