Electric underfloor heating under vinyl floor

[d000hg]

We're looking to put electric underfloor heating in a log cabin we're having constructed. The cabin is ~70m2 and will have a suspended wooden floor (not concrete).

It seems the precise details of what is required are different if we were having vinyl/lino, or wooden laminate, etc. Can anyone help me clear this up? I'm trying to get ballpark figures from Screwfix but some seem to need foil, others insulation boards. Obviously different flooring types have their own underlay requirements as well.

We are strongly leaning to vinyl flooring mainly as it appears to be more cost-effective but haven't ruled out laminate. The floor itself will just be regular MDF boards on the joists, well-insulated underneath.

Many thanks for any advice or information. We did get a quote from an electric firm but both their material costs and overall cost seemed remarkably high (£4500 for underfloor heating materials)

 

[crazydaze]

if you are laying sheet vinyl, you would 4mm pre-wet hardboard the floor and loose lay on top.

If you are laying Luxury Vinyl Tiles (LVT) you’ll need to 6mm ply the floor, microcoat or feather edge the screwheads and joints and use a High Temperatire Adhesive to glue it down.

If you are Laying Linoleum it’s a similar process to LVT

If you are laying Laminate, you need to lay it on a Underfloor heating Underlay for Wood flooring, something similar to Duralay Heatflow for Wood Flooring UFH underlay.

 

[crazydaze]

If you fit vinyl or LVT be very careful about using rugs, heat from UFH trapped in Localised areas can discolour vinyl easily.

Well worth looking at the tog rating for your underfloor heating system, it’s advisable to spec what flooring and and underlayment to the systems max Tog rating to avoid damage and high running costs

 

[bernardgreen]

Also avoid falling asleep on the floor when the heating is ON.

 

[foxhole]

Also avoid falling asleep on the floor when the heating is ON.

Does that apply to the dog?

 

[d000hg]

if you are laying sheet vinyl, you would 4mm pre-wet hardboard the floor and loose lay on top.

If you are laying Luxury Vinyl Tiles (LVT) you’ll need to 6mm ply the floor, microcoat or feather edge the screwheads and joints and use a High Temperatire Adhesive to glue it down.

If you are Laying Linoleum it’s a similar process to LVT

If you are laying Laminate, you need to lay it on a Underfloor heating Underlay for Wood flooring, something similar to Duralay Heatflow for Wood Flooring UFH underlay.

Just to make sure I have it clear, for lino you're saying:

1. Lay thin ply on the floorboards
2. Lay the underfloor heating mat on the ply
3. Lay the lino directly on top

What's the ply for?

Chatting to a chap today he pointed out there are two types of underfloor heating - foil based and mat based. Sounded like foil might be better for lino and laminate?

 

[bernardgreen]

Does that apply to the dog?

They say he never settled in the room when the electric heating was on.

 

[crazydaze]

Just to make sure I have it clear, for lino you're saying:

1. Lay thin ply on the floorboards
2. Lay the underfloor heating mat on the ply
3. Lay the lino directly on top

What's the ply for?

Chatting to a chap today he pointed out there are two types of underfloor heating - foil based and mat based. Sounded like foil might be better for lino and laminate?

The subfloor that you are laying it on needs to be billiard table smooth.

If you are laying Linoleum which is a very very specialised product you would need to 6 or 9mm ply, Microcoat and High Temp Adhesive over a wood subfloor or Self Levelling Screed over Concrete and High Temp Adhesive.

So it depends on your underfloor heating product but you would normally lay the underfloor heating product, and then a smoothing layer and then the flooring so as to not get lumps and bumps.

Sheet vinyl specification on floating floors requires 4mm pre-wet Hardboard or a self levelling screed over concrete.

LVT or Luxury Vinyl Tile flooring would require 6mm Ply and Microcoat on all edges and board gaps before the LVT is glued down with High Temp adhesive, on a Concrete floor it will need a high quality self leveling screed and glue down using High Temp adhesive.

You need to research the Underfloor heating system and specs but you cant lay Linoleum or vinyl directly onto it. You need to put a smoothing layer between it and the floor covering.

 

[d000hg]

Thanks, that's much clearer. The flooring we prefer is a big roll of vinyl which seems like a more modern take on Lino - a bit nicer on the feet. Is that what you refer to as sheet vinyl, just to be sure?
That "4mm pre-wet Hardboard" seems like what I had a quote for, they definitely didn't plan to go the screed route. Though if I was tiling, even on to a suspended wooden floor, I still WOULD have to go the screed route, correct?

I'd wondered since we're building from scratch if the new floor should be smooth enough to avoid the need for smoothly ply beneath the heating. We have to ensure the floor joists are extremely level for the foundation and cabin design we've selected and I'd expect the MDF flooring sheets would therefore be super-level too.But it seems like we need to make sure there are no imperfections AT ALL - presumably so thin wires don't break - so filling screws and taping joins might make a thin ply layer easier to do?

 

[crazydaze]

Thanks, that's much clearer. The flooring we prefer is a big roll of vinyl which seems like a more modern take on Lino - a bit nicer on the feet. Is that what you refer to as sheet vinyl, just to be sure?
That "4mm pre-wet Hardboard" seems like what I had a quote for, they definitely didn't plan to go the screed route. Though if I was tiling, even on to a suspended wooden floor, I still WOULD have to go the screed route, correct?

I'd wondered since we're building from scratch if the new floor should be smooth enough to avoid the need for smoothly ply beneath the heating. We have to ensure the floor joists are extremely level for the foundation and cabin design we've selected and I'd expect the MDF flooring sheets would therefore be super-level too.But it seems like we need to make sure there are no imperfections AT ALL - presumably so thin wires don't break - so filling screws and taping joins might make a thin ply layer easier to do?

Yup that describes sheet vinyl.

Ply as a construction product fitted correctly will be very level.

When laying the vinyl, what ever you lay it too has to be smooth or all imperfections and gaps, screwheads etc will show through.

Because Vinyl will be loose laid as a floating installation, hardboard is sufficient to lay as a smoothing layer.