Floor Insulation

barry75

Hi All
At the stage now that i need to look into getting floor insulation down before the underfloor heating goes in.Is there much difference between insulation types?Anyone any tips on putting this down.I put rigidboard between the rafters a few weeks back cutting it with a handsaw,is there any other way of cutting this stuff ?
thanks in advance
Barry

Qwerty?

I put in Xtratherm. Don't think there is much of a difference between it and Kingspan. I used 40mm and 60mm on the ground floor. I cut the 40mm around the insulated pipes, then put a layer of 60mm over these. This is to prevent heat getting into the cold water pipes, so you don't have lukewarm water coming from your cold taps. In rooms with no water pipes, I used a 100mm thick sheet, twice as fast to fit for obvious reasons.

I also put a layer of DPM under this. You will need a upstand of 25mm+ around all external walls, and in hindsite, I would have put a 60mm+ upstand at external door openings wherever you are putting wooden floors down.

fatchance

I used kingspan thermafloor 50mm 8"x4" sheets about 22euro a sheet. As said, cut strips of about 200mm and leave them sticking up around all external walls then push floor insulation tight against these. After floor poured you can just saw these flush with floor. All our cold water pipes had insulation lagging on them already. Sawing is the quickest way to cut kingspan, 100sq meteres took me 2 hours to do so it's easy. 50mm is recommended for ufh but you can go thicker depending on your sub floor levels, DOUBLE CHECK levels!

barry75

thanks for the replys lads,i went with xtratherm 50mm 8 by 4 sheets at 22 euro,the hardware store was looking for 25.50 per sheet for kingspan!I will be busy enough on my next day off putting this in.Has anyone ever used liquid screed with UFH,i am going to used this upstairs with the UFH,The installer of the UFH said that some of the liquid screeds heat up and cool down to quickly anyone ever heard of this?

fatchance

i looked at the liquid screed option to but it was very expensive compared to a load of concrete, plus they have to come before you put down your insulation in order to make the whole floor area watertight by laying down a special plastic sheeting, then you put you insulation on this. Reason being that because it is self levelling it is very watery and if there is a leak anywhere all the screed will run away and you will be left with a very expensive puddle! It's very handy stuff alright but it is not a wearing surface like concrete so you will need to cover it quickly with tiles or timber as it wears down with walking traffic, oh and don't get it wet after pouring it, it breaks down, that why i used concrete cus my upstairs was open to the sky till blocklayers came back