Can we install tiles directly on top of our underfloor heating?
Property Clinic: The UFH manufacturer’s guidelines should be strictly adhered to
Systems sourced from a supplier should be installed by an approved installer to protect the warranty. Photograph: Getty Images
A couple of months ago I submitted a query to you about installing underfloor heating (UFH) and tiling. Your reply was very helpful to us. We decided to go with porcelain tiles (after doing a bit of homework and short-listed the tiles). As we are now close to securing the keys of our newly-built home, we have begun our search for tilers who can install porcelain tiles over the UFH mats. We have checked with a few tilers and have received mixed responses.
Some tilers have told us that we need to add “compound levelling” before laying tiles because the tiles could damage the UFH mats. Others (including the firm supplying and installing our UFH mats) say that this is not necessary, and that it will be up to the tiler to decide on a case-by-case basis. Ours is a newly -built home, and the person who drew up our snag list checked the cement flooring and found it to be satisfactory.
So, can I ask you should we use compound levelling, or just install porcelain tiles directly on to the UFH mats?
Buying a house is a big step requiring careful consideration alongside all the other smaller decisions you will make towards creating your home. Looking back over my previous response, I note that my parting words were: “Finally, you want to ensure that any system you source from a supplier is installed by their approved installer, and that you are provided with a product and workmanship warranty.”
When I am advising a client in relation to a building product, I want to ensure that it will be fit for purpose and meets the client’s requirements, but I also want to ensure that it is installed/completed in accordance with the manufacturer’s guidelines. This is to ensure that we can avail of any manufacturer’s warranty and have some form of recourse if defective, assuming the contractor is not negligent. The initial question I would pose is to the suppliers of the under-floor heating product to confirm that any compound laid prior to the installation of tiling does not affect the warranties. Assuming you receive a positive response then I would have no concern with the tiler completing the installation as per their recommendation.
The purpose of the compound as you have indicated within your question is simply a protection method utilised by some tilers during tiling installation. I believe the practice originated from main contractors who would install UFH as part of a building base specification with purchasers installing their own tiling post-purchase.
The compound was installed to protect the flooring during viewings, owner, and tradesperson visits prior to floor finish completion. Finally, one element to keep in mind is that the additional compound does increase the depth of the floor. You will want to ensure that this does not cause a negative impact on the other floor finishes within the house which could create small trip hazards. – Andrew Ramsey
Andrew Ramsey is a chartered building and project management surveyor and member of the Society of Chartered Surveyors Ireland, www.scsi.ie