plumbing under or in screed

homewardbound11

I am having 2 layers of 50mm insulation layed in the floor. I am using standard radiators in the home with oil heating.

I had initially worked with the plumber that the plumbing for the down stairs radiators and water would be layed on top of the first 50mm and cut the second layer of 50mm to fit around it. Theny lay a dry screed of 75mm.

Now and i am guessing for ease of installation the plumber wants to now lay on top of the insulation and in the screed. He said he would lag the hot water pipes in the screed.

What is the preferred and best option. I would assume the benifits of putting it in the top layer of 50mm insulation would be better.

DoneDL

Either will do. If the pipework is 1/2 in and insulated it will be 30 mm thick, 3/4 in and insulated it will be 40 mm thick so worst case scenario you will still have 35 mm above the heating pipe. That said my preference would be to cut it into the second layer of floor insulation which gives 75mm clearance of screed which would lower the risk of accidentally damaging the pipe.

kscobie

and dont forget to allow for pipework expansion,ie dont pour concrete directly onto the insulated piping, it will lead to problems down the line, in the past, a covering of sand, especially on a bend or tee would always be the norm. Some engineers would disapprove but this works.