Any of you fellow pumpers pump grout over water heat tubes on existing wood floors? I get questions and calls for adding heat tubes to existing homes. Yeah i'm just the pumper but we see alot of stuff. Gyb crete isn't available and pea rock mix is heavy, I've been recommending this mix. Anything out there thats more flexable or lighter?

Lots of guys around here use just a 30mpa grout mix straight concrete sand. In my own home I used a 10mm small stone mix 1.5 inches thick colored and stamped on our wood sub floor.  It's 15 years old now and looks like the day it was poured my kids ride bikes on it, roller blade and play hockey on it .

I've pumped 3-4 homes with that technique just haven't been back to see the long term durability. Good to hear yours is holding up, i bet you like it. I recomend the use of fiber, seems like it would help. Lighter weight and crack resistance would be a big plus.

Here's a crazy question: what would happen if a guy mixed saw dust and portland together. :)

Try it and let me know 

I made some up today with mortar mix. Its leaner than id like but what i had in the shop. Added about 50 50 mortar and saw dust i had on hand. Will see if it sets up..

Yeah, it didn't set up. Oh well

lol cudos for trying

Last ones I did was with 25% stabilised sand and I like the fibremesh personally