what will happen if dry lumber are used as forms for concrete slabs are fitted too tight agains the wall?

Question

about rough capentry

Answer 1

They cant be too tight,, unless your putting forms against an existing wall,, otherwise you will want to use pressure treated wood because you will end up leaving that form in between,, the 2, Im not quite getting what you mean by to tight against the wall,, but otherwise, If your butting the forms up to another wall,, they cant be to tight,, you dont want a leak and what could be a weak spot in your forms,, you want to be sure to drive stakes into the ground at a 45 degree angle so that the heads of them butt right below the outside of the forms,, and then drive a nail into the stake into the form so it will hold your form straight and keep it from bowing in or out,, use a string line so you can see where it needs to go in or out to keep your slab square, If your pouring against an existing slab,, I wouldnt use a form between the 2 unless you need one for some reason,, the best way to keep it level and all with other is to pour right up against it,, and if you do use a form, when you go to pull out the form of course you will have the gap between the two,

Answer 2

I'm not sure i get ur question? if your wondering if its gonna hurt anything to leave wood between your existing slab and new concrete the answer could be yes if your pron to termites, other wise if you treat it with insecticide and cover it with your floor covering you might be ok.

Answer 3

seal it so that rain can't get down behind it and rot it out