R
Ren+
Hi all
I have a new conservatory floor that will be receiving electrical underfloor heatmat and then will be tiled. The builder has laid a layer of polystyrene(about 20 to 30mm thick) on top of the concrete before laying the final screed of about 75mm. They did it to save cost on the screed (i.e. made a calculation error when calculating their finished floor level initially).
My question is whether I need to lay insulation board before the heatmat if there is polystyrene under the screed. There will obviously be heat transferred into the screed, but is it really going to be substantial enough to justify insulation board. Let's say the u/f heating kicks in at 6am and then shuts off at 10 pm again. Is the screed going to loose it's heat substantially enough during the shutdown period. It's quite a sizeable conservatory (25sq.m) which has no rads. Therefor, the u/f heating will be the sole heat source.
Also, my concern is whether the layer of polystyrene poses a risk for the screed to crack easier in time ... not so good for tiled floor.
I'd obviously want to save costs for the client but not forgetting longterm implications. Insulating the floor(6mm) will cost about £500 lab & mats.
I look forward to your posts and say thank you in advance.
Ren+
I have a new conservatory floor that will be receiving electrical underfloor heatmat and then will be tiled. The builder has laid a layer of polystyrene(about 20 to 30mm thick) on top of the concrete before laying the final screed of about 75mm. They did it to save cost on the screed (i.e. made a calculation error when calculating their finished floor level initially).
My question is whether I need to lay insulation board before the heatmat if there is polystyrene under the screed. There will obviously be heat transferred into the screed, but is it really going to be substantial enough to justify insulation board. Let's say the u/f heating kicks in at 6am and then shuts off at 10 pm again. Is the screed going to loose it's heat substantially enough during the shutdown period. It's quite a sizeable conservatory (25sq.m) which has no rads. Therefor, the u/f heating will be the sole heat source.
Also, my concern is whether the layer of polystyrene poses a risk for the screed to crack easier in time ... not so good for tiled floor.
I'd obviously want to save costs for the client but not forgetting longterm implications. Insulating the floor(6mm) will cost about £500 lab & mats.
I look forward to your posts and say thank you in advance.
Ren+
