I’ve bought and cut some 3/4 marble slabs for an entry hall in my house. In speaking with the local stone merchant I’ve learned that it needs to be laid on a 3/4″ bed of ‘dry pack’ mortar. The stone will also need polishing once laid. now the questions start.
1) The dry pack mortar… is simply common mortar mix with insufficient water to make is wet? This is how it was described to me and I just want to be sure I understood correctly.
2) The area is 6’x6′. Floor joists are rough 2×12 with a support wall running the length of one side and another coming to within 10′ on the other side. The outer foundation wall is also within 10′. Should I crib the joists or take the masons word that the weight won’t be a factor. The stone merchant has been to the house and has seen the proposed location.
3) When polishing, should I keep the shine to a minimum? I’m a little leery to put a high gloss finish in an area that will be subject to water as it may become very slippery.
Any thoughts will be greatly appreciated. Thanks. Chris.
Replies
The semi-dry mix [I would suggest about 8:1, sand:cement] should have just enough water added that when you take a handful, squeeze it and open your hand, it stays together as one lump, but not so wet that the cement stains your fingers.
A bed 3/4" thick sounds a bit thin to me -- the marble here was laid into a cement slurry on a semi-dry bed 2" thick.
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and was on a concrete slab. The polishing process involves some heavy equipment too and although this method of setting the stone does allow for a little movement compared to a wet bed I'd still be stiffening up a sub-floor on bearers.
IanDG