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icanreachit said
Question that I noted on KVR's build. Can you save time by pouring into forms already lined with foam? I know KVR laid foam down, poured on top, dug out around, placed foam, then re-tamped. Can you lay down the foam on the bottom and the sides before pour? This should save some time. You'd screed to the foam but... oh well? I was also wondering about using foam as forms? You'd still have to hold them up somehow, that part may negate the speed bonus.

I am going to form up the footings, then put the foam in the bottom, then rebar, then pour.  Which means I will be putting the foam on the sides once we strip forms.

The 2 inch foam (XPS) is not strong enough to use as a form, it needs support behind it so it doesn't blow out. 

Would it save time to set foam on three sides before the pour? I don't think it will save much if any.  Once I strip my forms I can just slap on my 8ft lengths of 12 inch high foam and back fill accordingly from the outside and likewise from the inside. I will fill in on the inside first in order to get ready for the floor pour. I probably won't even do the outside of the footing till all block and floor work is done; I just the foam to get beat to hell while the job is going on.

You could certainly set all the foam in the forms at one time, I just think it is a bit more of a pain that way and it potentially will get beat up more than I like...but, if you did all the foam right off the bat, you would have some very clean form boards when your done.

Thanks K.  That is a nice product.

I decided to go with the 2x10s for forms, then line the inside with the Tyvec I have at the Farm. This will keep the form boards clean for reuse.  I would think the laying in of the Tyvek will go pretty fast.

So, we will form it up and stake it, then lay in Tyvek, then putt in the Rigid Insulation in the bottom of the form, then rebar with perches.

When we strip the forms I might cut off the Tyvek if I have time, I don't think it will hurt anything if I decide not to.

That's the plan for the footers...but things always change...ugh.

That's what I am thinking...once it's laid in I might walk around with a screwdriver or knife and poke a few holes in the bottom of the wrap to help some of the moisture get out a little easier...but forms will be staying on for a week due to schedules/work.

Once we have the 1st course laid I am going to drill then tap them in.  Since we will have the slab coming up 4inches on the inside and then back fill on the outside we will be okay. 

Pinning the wall to the footing might not be necessary, but I only get once chance to do it.  So, as long as the HF hammer drill holds out that day I should be good.

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As for the tyvek, only concern there is: if it will screw up the setting/curing of the concrete...will it breathe/let enough moisture evaporate?...that is why I am thinking of poking holes/making some slits in the bottom.