Laying UFH insulation board

brendan_donegal

Any tips on how to get a trench in the insulation board for pipework running under board?

Cold/hot water pipes, not UFH pipes :-)

You can just cut the board when you run into a pipe and then continue on but got to be neater to just embedded it into the board?
Maybe I'm being too fusy?

peterc14

Is it Kingspan type insulation?

What thickness are you laying?

manufan16

I am in the middle of working out my requirements for this and I intend on buying some 25mm some 50mm some 100mm sized PIR sheets to cover the different pipe sizes at ground level.

esox28

we use a skill saw 'circular saw' set to required depth, you can get special blades but a course/ rough saw blade will suit. then just use the back of a hammer to claw out your track, sometimes helps when doing long runs to cut across every meter or so.

brendan_donegal

Yes ground floor is easy I am laying 2x 50mm sheets so when i come accross a pipe I just cut the board and the 2nd layer of sheets covers that void.
First floor is the issue, only 1 layer of 50mm.

ESOX28: I've been doing similar with blade and a hammer, very messy.

No special tools available then or tricks of the trade...

Do-more

There is such a thing as a hot wire cutter but I don't know where you could find one at short notice.

sydthebeat

typically the u value for a floor with UFH is 0.15 minimum.

this tends to be approx 140mm PIR insulation.

as your pipes will be no more than 50mm, why not install the insulation in two layers... first layer of 50mm boards cut to suit between the pipes. the second layer of 100mm boards laid over.

edit:

just seeing that its a first floor issue with a 50mm board. Assuming youve no screed already poured, i would just pour a 75mm screed over the H+C pipes, and then insulation over that.

BTW Your ground floor insulation of 100mm PIR is insufficient

esox28

why do you kneed insulation on the first floor is there ufh? anyway if you are using 19mm pipe insulation (grey stuff ) you will need this about 20 - 25 mm below screed level as the pipe and insulation has a habbit of floating if not securred every 1.5mtrs

brendan_donegal

I asked that question once and got a very good answer that I can't remember :-)

All pipes are anchored to the floor.

I have just been cutting the board, nearly done, really pleased, plumber reckons neatest job he has seen, so I'm good on this subject, thanks for all the replies.