Stuart X-Ray

Not yet, we are still trying to get the DPM to fit round all of the corners, because nothing is square it's tricky to make a hospital corner fold. We have 18 inside corners and 16 outside corners to form on the DPM. The Celotex issue is still not resolved and wheat I found so far is worrying. The boards have shrunk on one side only by 5-10mm and that's why they have bowed. Celotex can't tell me why but there are loads of cases on line where this has happened mostly in walls and roofs where it has become loose or called out. It is way to stiff to straighten without cutting it. So we may need to scrap it and get something else, probably Kingspan, certainly would not touch Celotex again for UFH.

Part of the full renovation of our stone cottage is to build and install a solid oak single run staircase, the foot of which will sit on the ground floor. The floor will be quarry tiles on a 50mm screed containing the ufh pipes, that sits on 100mm of PIR board and under that is 100mm of concrete. Should we put a steel spreader plate or similar in the screed at the foot of the stairs? has anyone any ideas? Thanks, Stuart.

We are a bit limited on the depth, base is solid rock in places and so we can't dig down deeper. the blinding which is done now, is from about nothing to 50mm depending on rock shape. Actually we've set cable ducts and a land drain below the DPM for ground floor electrics and prevent the under ground stream from flooding us. Standing on the boards doesn't seem to move them at all but we will try clamping for a couple of weeks to see if it works. I'm thinking that slitting them might be the answer. BTW the 100mm of concrete is under the PIR, there will be 50mm of pipes and screed on top.

We started to renovate our 200+ year old stone cottage nearly six years ago. Complete roof replaced so it's dry inside. Excavated the floor out inside down about 300mm to install a solid, insulated UFH system with ASHP. The project stalled due to Covid and the PIR boards have been in storage for 18 months. The intention is to construct a ground floor consisting of: base rock, about 20-50mm blinding, DPM, 100mm C20 concrete, vapour barrier, 100mm PIR, second vapour barrier, UFH pipes stapled through patches into PIR, 50mm pumped screed, quarry tlies. We are currently putting the DPM down, concrete pour will be in about a month from now. However, we uncovered the Celotex GA4100 and every sheet has bowed/curled up by 10-20mm, all in the same direction. Can we slice them into strips and foam gun together flat or do we scrap them and buy new, if so which ones won't curl up? Has anyone had to deal with this before? Has anyone had this happen after the floor was laid? The thought of the screed lifting up by 20mm is a bit scary. Any advice would be welcome. Thanks, Stuart.

We are just getting to your stage and used 32mm Duo pipe with a Samsung 8kW unit. Did you bury your Mibec in the ground? How deep? Did you insulate the trench? Thanks, Stuart. Roseland Cornwall.

Apologies for jumping in on this post but we have 14 sheets of Celotex GA4100 that we have stored for 18 months on the upstairs floor in a damp but not wet cottage and every sheet has bowed in the same direction by about 20mm. This was destined for UFH so is now pretty useless. Saint Gobain (Celotex) technical have not been helpful as to the reason why this has happened. I suspect that there are internal stresses from the manufacturing process and over 18 months this has relaxed each sheet in the same direction, even though they were stacked randomely in one pile off the floor and covered with a sheet. So I think moisture does have a long term effect. I'm now talking to Kingspan and Reticel to see what they say.