Hi I am having a new floor laid - doing what I can myself- but am not tackling the 30sqm of concrete and screed over underfloor heating.
Planning to lay some travetine tiles once flooring is done - but really unsure if need a decopling membrane. It will add nearly £4-500 to job - which I can't really afford- how essentil is it?
Keep in mind I'm not an expert, just spend too much time here on the boards.
My understanding is tile will expand and contract at different rates than concrete. A decoupling membrane allows this expansion/contraction to happen without damage, otherwise this can cause tile and grout to fail, crack, and/or come loose.
This is more of an issue in colder climates than in temperate climates. Also, adding the underfloor heating will increase the temperature fluctuations and so will increase the chance of problems.
Are you a betting man?
Personally, If I were adding in-floor heating of any sort, I would go with a membrane.