Got me a gert chunk of limestone for use as a hearth. Ive cut it ready to install. Currently a screed which is flush (or there abouts) to the oak flooring, when the stone is sat in place, i dont really want to raise it up any higher than is essential, or there will be a big gap between the underside of the stone and the flooring. I fear if I sit it on a mortar bed. it will raise it up a bit too high... A thin cement slurry I fear will crack away... Tempted to use a tube of stixall Any suitable methods?