Unit weight of a sand cement mortar vs. unit weight of concrete

[ajk1]

Does anyone know if the weight of 2" thick setting bed of sand-cement mortar is significantly less than 2" of concrete? 2" of concrete would of course weighs 25 psf.
Also is there any known problem of bonding tile to plywood versus bonding to mortar setting bed, in terms of the bond strength that can be developed?

 

[racookpe1978]

Concrete weight WILL vary by relative concentrations of rebar, sand, cement, rocks and gravel. The 25 lbs is only an average. Depending on aggregate stone, the difference between stone and sand is slight, but not zero.

how accurate do you need the answer?

 

[ajk1]

Within a few percent is sufficient. From my internet search after I posted the question here, it seems that mortar is only 6% less unit weight than concrete
i.e. 2160 kg/cubic m vs. 2300 kg/cubic m. Does anyone have anything different than these numbers?

I am still interested if there is any problem in adhering 1/8" thick limestone flooring to plywood. I cannot think why there would be, but someone has suggested that I check it out. I would have thought that an adhesive manufacturer could recommend an adhesive that would bond well to both plywood and limestone flooring. Any thought or comment?

 

[hokie66]

I wouldn't worry about the difference in weight between mortar and concrete. About 150 pound/cubic ft or 2400 kg/m^3 is about right.

1/8" thick limestone flooring? Sounds very thin, and I would think the flexibility of a wood floor would lead to breakage in the limestone.