[Fix'n it]

will xps get soaked if it is submerged ?

 

[Windows on Wash]

Over time, yes.

All rigid foams, commonly used ones, do.

XPS is by far the best well suited for subsurface and moisture contact.

http://commercial.owenscorning.com/assets/0/144/172/174/e45fe07d-5cc9-4e4b-866a-5e35d75090ec.pdf

 

[Fix'n it]

ok, why i ask. i have a grading problem in my back yard. hard rains a lot of water works its way down to a 1 1/2 car garage slab outside my back door. i want to make a barrier so the water goes around it. my idea is to bolt 6x6"x10' PT to the slag edges. and use fanfold as a gasket. then backfill.
any other ideas welcome.

btw, whatever plan i decide on will not happen until spring. i'm just planning right now.

 

[Ron6519]

Why not re-grade and solve the issue that way? Can you post photos?

 

[Nestor_Kelebay]

There are two kinds of polystyrene foams; extruded and expanded. The extruded is like the blue "Roofmate" stuff, and the expanded is typically white and looks like it's made out of polystyrene "beads".

Which one is "XPS"?

 

[Fix'n it]

Why not re-grade and solve the issue that way? Can you post photos?

i have been, where i can, and some more to do. but one side of the slab is not on my property, its over the line about 1'. i didn't make it this way, and my neighbor has no problem with it. anyway, i cannot regrade there as this side is right were the new swale will be and on my neighbors property. so i am thinking PT 6x6 bolted down to the edge of the slab with fan foil as a gasket.

 

[Fix'n it]

There are two kinds of polystyrene foams; extruded and expanded. The extruded is like the blue "Roofmate" stuff, and the expanded is typically white and looks like it's made out of polystyrene "beads".

Which one is "XPS"?

idk what the roofmate stuff is. but xps is not the bead kind.

 

[Fix'n it]

here is the slab. i am standing in my back door. i just happen to have those block, so i put them there as just cause, and backfilled. but, i don't see them stopping water if the dirt behind them gets saturated. i didn't have enough blocks to go all the way over to the left corner.

the houses in back, and my neighbor, they are graded higher than i am, so i get a lot of their water. i am basicly the low spot.

before and after the blocks.