underfloor heating.

[Rancot]

Hi. I am a keen DIY enthusiast over many years. Came to this site when researching UFH. One job I did not enjoy previously was using self levelling compound - it did not level! maybe too thick? However as I am thinking of laying UFH loose cable I will need to use it so any tips would be appreciated. Also, has anyone ever recommended using al. foil under 6mm insulation board to increase the insulation but keeping low height of thickness? Would this be dangerous and make the wire overheat etc?? would be working on concrete base.

 

[Andy Allen]

What SLC did you use?

 

[Qwerty]

In theory it would work in radiating the heat back, but how would you ever fix this to ensure a movement free substrate? Im certain it would void any warranty as well as create potential catastrophic issues in the future with movement. Use just the insulation boards or go to 10mm if you can

 

[AliGage]

 

[p4ulo]

some companies will sell you a paint-on solution that "improves" insulation properties. maybe try that under 6mm boards?
I used 10mm in the end, and I was worried about height, there are gains over 6mm, but if you are really conscious on it, go for 6mm, I'm sure it'll be fine.
Someone used a different SLC on a thread the other day, and it mixed watery and was very easy to level.....Gimme a minute I'll add the name....

ITS UZIN.....do some research.....might be able to find some at a decent price near you? Good luck - pictures please!

 

[Rancot]

Hi. I am a keen DIY enthusiast over many years. Came to this site when researching UFH. One job I did not enjoy previously was using self levelling compound - it did not level! maybe too thick? However as I am thinking of laying UFH loose cable I will need to use it so any tips would be appreciated. Also, has anyone ever recommended using al. foil under 6mm insulation board to increase the insulation but keeping low height of thickness? Would this be dangerous and make the wire overheat etc?? would be working on concrete base.

Thanks your points have made me give more focus to movement.

 

[Rancot]

some companies will sell you a paint-on solution that "improves" insulation properties. maybe try that under 6mm boards?
I used 10mm in the end, and I was worried about height, there are gains over 6mm, but if you are really conscious on it, go for 6mm, I'm sure it'll be fine.
Someone used a different SLC on a thread the other day, and it mixed watery and was very easy to level.....Gimme a minute I'll add the name....

ITS UZIN.....do some research.....might be able to find some at a decent price near you? Good luck - pictures please!

Thanks - saw this and it looks to be good

 

[AliGage]

Many people get fooled by SLC.
You still need to move it around to where it's needed. It'd not just a case of pouring and it'll level itself. It's does to a point. But it's more localised self smoothing.

 

[Rancot]

What SLC did you use?

Thanks for replying. It was ages ago can't remember name but it was from local DIY store. Uzin looks good so I will think about this.

 

[Qwerty]

I will now give my opinion on your situation...... Forget the foil idea straight away! Prime the floor with an acrylic primer and fix 10mm insulation boards using bagged cement tile adhesive. An easy, recommended and trouble free installation. Sorted!
As for SLC, any quality fibre reinforced bagged SLC poured evenly over the floor and floated carefully will leave a level smooth finish

 

[Chalker]

The foil won't be much help as it reflects light. Underfloor heating works initially through conduction, from the wire/pipe into the finish layer. This then emits heat through transfer to air and a little light wave energy.
Therefore to get the most heat into the room, You need a good dense mass above the element, this will give better heat transfer to the room and the thicker the insulation mass under the element, it will loose less heat downwards.

Sorry for going all technical!

 

[Rancot]

I will now give my opinion on your situation...... Forget the foil idea straight away! Prime the floor with an acrylic primer and fix 10mm insulation boards using bagged cement tile adhesive. An easy, recommended and trouble free installation. Sorted!
As for SLC, any quality fibre reinforced bagged SLC poured evenly over the floor and floated carefully will leave a level smooth finish

Thanks. This is what I want to do - however it will take this floor above the adjacent floor which is sculptured porcelain tiles. These really could do with covering as the floor is the result of 3 different room extensions. What is the best way of covering these tiles, I thought of vinyl over hardboard or thin ply as I cant go direct on to the tiles because of the ridges in their pattern. Or should I just self level again? This job is getting like pinoccios nose!

 

[Rancot]

The foil won't be much help as it reflects light. Underfloor heating works initially through conduction, from the wire/pipe into the finish layer. This then emits heat through transfer to air and a little light wave energy.
Therefore to get the most heat into the room, You need a good dense mass above the element, this will give better heat transfer to the room and the thicker the insulation mass under the element, it will loose less heat downwards.

Sorry for going all technical!

Thank you for taking the time to reply - interesting

 

[White Room]

I doubt whether slc would stick to ali foil...

 

[Dan]

Hi. I am a keen DIY enthusiast over many years. Came to this site when researching UFH. One job I did not enjoy previously was using self levelling compound - it did not level! maybe too thick? However as I am thinking of laying UFH loose cable I will need to use it so any tips would be appreciated. Also, has anyone ever recommended using al. foil under 6mm insulation board to increase the insulation but keeping low height of thickness? Would this be dangerous and make the wire overheat etc?? would be working on concrete base.

Welcome to the forum.

Yeah as above. SLC is more of a push it around and it'll sort its self out kinda stuff.