I have a monolithic slab to do, requiring R-15 around the perimeter. Is there a better way to do this than 3″ of Extruded Polystyrene “pink board” beveled and flashed all around?
Polyisocyanurate with the foil face is 7.5R per inch but It’s not approved below grade or wet, right?
Replies
Not that I know of. I just finish doing a retro fit for a house and I used 2" blueboard as per the inspectors requirements.
Sorry.
Right. the extruded pink board is your best bet. Bevel. Take some colored flashing and have a guy bend it to shape. Pretty straight forward; reasonable finish I think. Don't really know about durability of the metal in contact w/ the ground ... suppose it would be OK. It does provide a pretty clean line and foundation base (visually) for the house. I've seen where they also hang the bottom plate over by like 1", too, but that doesn't cover it for you.
You can skim-coat it with Thoroseal, or if you really want a bulletproof finish, attach some expanded metal lath and then apply the Thoroseal. You can use green board from a masonry yard, it's harder and denser than blue or pink board.
But essentially, you have the right idea.
Thank you.
Who makes the harder-denser 'greenboard' from the masonry yard and what's the R value per thickness?
Same as pink?
Pat
Don't know, and don't know. Do you have a local masonry yard?
Yard yes,
Mason's Supply. I'll ask them--but I've never seen the product there.
Thanks Mike,
pat
If it's extruded polystyrene, it's all R 5 per inch. You shouldn't use polyiso in a place like that. I have seen (and used) the foam on the foundation protruding from the plane of the wall a time or two. It's a detail to be avoided IMO. If you use metal, it's bound to get beat up with few options for repair. Stucco is better, but still it will look butt ugly. Plus with stucco, how would you handle the top edge? Seems like you would have to put a flashing on top, which again would tend to get beat up.If it were MY house, I'd hang the plates two inches, and then either fir the walls with strapping or add an inch of foam to get the siding plane out past the foundation.
I painted mine with Kool seal. An elastomeric roof coating. Its white so I had it tinted grey and it looks like concrete. I used 2 inch pink. Havent seen 3 inch.