Hi all, i'm after some advice regarding the amount of sand and cement i need to do some screeding in my house. My house was tiled about 20 years ago, tiles layed in a screed 5 cms thick. The screed is really drummy and tiles are popping up so iv'e started breaking it away and plan on re doing the screed myself before having it re tiled. Iv'e done some concreting before so pretty confident about doing a decent job. My first question is approx how much sand and cement will i need to do 70 m2 at a thickness of 5cms? Will a ratio of 4 parts sand 1 part cement be ok; also the concrete slab underneath has inbuilt heating, that being the case do i need to add anything else to the mix or is sand and cement enough? A few questions there but any help would be appreciated. Thanks Jamie

add plasticiser and i would get some fibre;s to add as well , travis perkins do it

it should really be a minimum of 65mm screed.

sorry missed that 5cms aint deep enough as doug says