Mon, 25 May 2026 12:59:34 +0100 https://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1708&Focus=20457#Comment_20457 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1708&Focus=20457#Comment_20457 Mon, 12 May 2008 08:50:50 +0100 Roger
At the stage of laying a stone flag floor on insulated concrete subfloor with UFH under 65mm screed. Looking at 30mm sandstone flags, 600x600mm or similar. Was planning to lay them on a lime mortar but was blinded by science at tile stockists. He suggests planing surface of screed to dead flush, turning on UFH for a few weeks to open up any cracks; filling them with a filler compound, sealing the screed, laying a 'flexible adhesive'; then stone; then seal.

Anyone any experience of this and any pointers? Would prefer a simpler route if possible.

Thanks.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1708&Focus=20478#Comment_20478 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1708&Focus=20478#Comment_20478 Mon, 12 May 2008 16:01:39 +0100 tony https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1708&Focus=20517#Comment_20517 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1708&Focus=20517#Comment_20517 Mon, 12 May 2008 23:27:26 +0100 Cliff Greening
Your local tile stockist is talking crap. no experience. I have installed 2 UFH systems using a lime screed encapsulating UFH unbonded on 60mm 300Kpa extruded polystryene insulation on a concrete oversite. Random thickness York stone flags were then bedded on top of screed with lime mortar. The first building was a 12th century manor house in Alderly Edge and the second an adjacent barn. Both projects went like a dream with no problems.

I have photos of the barn which I can email you if you wish. You can contact me at: warmwater@blueyonder.co.uk I will talk you through the project.

Regards Cliff.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1708&Focus=20524#Comment_20524 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1708&Focus=20524#Comment_20524 Tue, 13 May 2008 08:41:53 +0100 Roger
As I suspected. Will bed them on lime mortar. As far as I can see that will take up any thermal expansion/movement that might occur, leaving the flags unharmed.

Thanks again, Roger.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1708&Focus=20529#Comment_20529 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1708&Focus=20529#Comment_20529 Tue, 13 May 2008 09:50:57 +0100 Cliff Greening
Do not forget perimeter expansion detail and expansion joints in screed. Doorways can crack along with any projections into room like a fireplace. Any screed will crack for lots of different reasons you just have to try and elliminate them.

Regards Cliff]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1708&Focus=20534#Comment_20534 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1708&Focus=20534#Comment_20534 Tue, 13 May 2008 11:39:11 +0100 Roger
Around the perimeter there is 30mm of EPS but each of the two floor areas (seperated by a step) were cast in 1 go. (10mx5m). Do you think there should have been expansion breaks within these areas?

Roger]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1708&Focus=20566#Comment_20566 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1708&Focus=20566#Comment_20566 Tue, 13 May 2008 18:41:03 +0100 tony