Weep holes and tile

[Oceanrover]

Hello all, I'm using the casil / foamglas floor method and it was recommended to add 3/8" weep holes. I saw in the forms some members had also added mosaic tile turned upside down. Is this necessary? Getting ready to lay the floor and would like some advice, I priced 4 sq. Ft of mosaic at $60 or is there a cheaper alternative or do I even need to add more to the floor?

[SableSprings]

The mosaic tile is simply an easy method to channel any water to your weep holes. The foamglas will not absorb water, so that's really all you need since it's keeping the calsil board high and dry. I suggested putting in the mosaic sheets if you couldn't find or didn't want to spend the money on the foamglas. Also, I was looking at mosaic tile sheets that were leftovers, broken sections, discontinued patterns, and so on. Yard sales, neighbors who had tile work done, etc., were places to pick up these "excess" sheets for really cheap.

I liked using the mosaic square sheet stock because of the "built-in" channeling and the webbing that supported the ceramic board while keeping it off the deck, but broken pieces of any porcelain tile could be used. In your case, the foamglas and weep holes are all you really need to provide a water barrier (and drain)...it's just that some of us tend to want to double down on protection from water coming up from below.

Hope that helps.

[Oceanrover]

Thank you mike,

I was at the home depot yesterday and they had boxes of mosaic tile 75% off (10 sheets 11"x12"per box) for $11.99) so I bought a box. We don't get as much rain as you do up north but when we do it's been a lot. Thank you for the great advice, I like the idea of added protection so I may get a couple more boxes at that price and feel more secure down the road with my build.

Regards,

John

[MarkDLxu]

I revive this post for one question... if I already know where to put the CaSil board, is it possible (during the curing), make a drainage channel just outside the CaSil perimeter ?
in this case water that remains on the concrete slab cannot reach the board from outside

[SableSprings]

I revive this post for one question... if I already know where to put the CaSil board, is it possible (during the curing), make a drainage channel just outside the CaSil perimeter ?
in this case water that remains on the concrete slab cannot reach the board from outside

You can put a channel or build a low dam around the CaSil board perimeter, but water is amazing in how it can find a way in, think wicking & capillary action. It also involves a fair amount of work to create a drainage channel that will not clog up and actually redirect water to your insulating board. I think most of us on the forum would agree that pouring your hearth with a slight dome (so water drains away from the oven base), installing weep holes in the hearth, and adding porcelain tiles between the hearth (or a base Foamglas board) and CaSil board (to isolate the "water hungry" board from direct contact with the hearth concrete slab) would be the ideal build design...along with putting a roof over the oven and you...