I understand the mortar bed is made 4/1 or 5/1 when I lay my 20mm porcelain outdoor tiles. Would it be detrimental if I was to increase the depth of mortar in some places to 70 or 80 instead of the recommended 40/50mm depth. Just to get my fall rate away from house as it meets my retainer wall. I have compacted a solid bed of mot to a depth of around 100mm. Thank you all in advance regards David.