insulate existing concrete floor

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empacher48

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#2501225 9-Jun-2020 09:53

timmmay:

The biggest thing we do is heat the house consistently in winter, so it warms through. Weekend and days we're home heating is on from 6am to 10pm, turned down a bit when we go out. Weekdays it's on 5am to 7am and then 3pm to 10pm, even though we're not home until 5pm. On super cold days we turn it down to 18 rather than off. Even though it's off a bit the house stays warmed through, so we're not heating it from really cold.

As my father used to say in winter you have to heat the bones of the house, once they’re warm it’s easy to keep it warm.

Insulation helps keep the bones warm.

kobiak

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#2501231 9-Jun-2020 10:06

timmmay:

When I insulated under my wooden floor it made little difference to temperature or comfort, but that may be different for a concrete floor. Ceiling insulation made the biggest difference, wall insulation made a small difference, double glazing somewhere between the two. Removing downlights made a good difference.

The biggest thing we do is heat the house consistently in winter, so it warms through. Weekend and days we're home heating is on from 6am to 10pm, turned down a bit when we go out. Weekdays it's on 5am to 7am and then 3pm to 10pm, even though we're not home until 5pm. On super cold days we turn it down to 18 rather than off. Even though it's off a bit the house stays warmed through, so we're not heating it from really cold.

Yeah I have ceiling and walls insulation, no double glazing. I'm sure my slab has some insulation, but I don't see how it would make easier to heat up concrete/or stop it to drive cold into the ground level without thermal insulation inside the building. I'm debating to spend $500-700 on ground level flooring if that won't have much positive change... :(

helping others at evgenyk.nz

kobiak

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#2517121 4-Jul-2020 10:21

Alright. Just to update on the progress and results.

I used Expol XPS 10mm sheets to lay on the concrete + foil underlay 3mm + 10mm laminate.

XPS board is so hard I could stand on it and no or little damage. When laminate plank is on XPS - there is absolutely no damage and it feels rock solid.

The flooring is rock solid with no creaking, movements, etc.

The main goals were:

1st. to make room feel warmer

I think it does feel warmer. It was 4-7C nights in the last 3 days in WEST AKL, and I could say ROOM feels warmer. Temp difference is about 2-4 degs or how it was. So it stays 14-16C (sensor is 1m from the floor) when temp drops to 4-7C outside. So that's the success!

2nd. less heat loss or I would say less cold coming to the room from the bare concrete.

I think there's less cold coming in as sensor 2cm from the floor shows 1-1.5 deg warmer as it used to be. So no it's 12-14C, and it was 11-13C. I hope it would improve overtime as well. And when I heat the room with my little fan heater, room stays warmer for far longer than it used to be. Next door Garage with concrete floor has 11-13C. So that's the success!

3rd. and to make it feel warmer to walk on the floor without slippers

Laminate floor feels cold. So I'm still in slippers/shoes. BIG FAIL. and side effect, my boss chair is rolling like on ice, need a rug or something.

Overall. $130 for 10 sheets of XPS + $280 for laminate and underlay = I'm happy.

helping others at evgenyk.nz

Kickinbac

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#2517191 4-Jul-2020 13:57

Good work. Where did you buy the expol xps foam from?

kobiak

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#2517335 4-Jul-2020 19:52

Kickinbac: Good work. Where did you buy the expol xps foam from?

Mitre10 special order. 3 days

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justabum

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#3110835 1-Aug-2023 22:23

kobiak:

Alright. Just to update on the progress and results.

I used Expol XPS 10mm sheets to lay on the concrete + foil underlay 3mm + 10mm laminate.

XPS board is so hard I could stand on it and no or little damage. When laminate plank is on XPS - there is absolutely no damage and it feels rock solid.

The flooring is rock solid with no creaking, movements, etc.

The main goals were:

1st. to make room feel warmer

I think it does feel warmer. It was 4-7C nights in the last 3 days in WEST AKL, and I could say ROOM feels warmer. Temp difference is about 2-4 degs or how it was. So it stays 14-16C (sensor is 1m from the floor) when temp drops to 4-7C outside. So that's the success!

2nd. less heat loss or I would say less cold coming to the room from the bare concrete.

I think there's less cold coming in as sensor 2cm from the floor shows 1-1.5 deg warmer as it used to be. So no it's 12-14C, and it was 11-13C. I hope it would improve overtime as well. And when I heat the room with my little fan heater, room stays warmer for far longer than it used to be. Next door Garage with concrete floor has 11-13C. So that's the success!

3rd. and to make it feel warmer to walk on the floor without slippers

Laminate floor feels cold. So I'm still in slippers/shoes. BIG FAIL. and side effect, my boss chair is rolling like on ice, need a rug or something.

Overall. $130 for 10 sheets of XPS + $280 for laminate and underlay = I'm happy.

Hi kobiak

How has the insulation gone?

Did you install a vapour barrier between the concrete and the Expol XPS?

Want to insulate and install a nice floor on a concrete floor in garage to make it habitable.

Cheers.

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cddt

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#3110919 2-Aug-2023 09:14

kobiak:

THis morning outside 8.1 deg, ground level with no heating 16.6 deg (sensor is ankle high from the floor so it's around 1.5-2 deg warmer in the room).

That's not bad actually. On Saturday my living room was 10 degrees when I woke up, outside temperature would have been 5 or so.

neb

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#3111094 2-Aug-2023 15:35

kobiak: Heater heats the air and its get too hot to wait until floor is heated too :(

Current solution is shoes :) but meh I don't like it.

Expensive and messy, but you can retrofit underfloor heating either by cutting slots in the concrete and laying it in them or by building up a thin layer of filler with heating coils embedded. With passive insulation there's really not much room to add anything significant, and you've still got cold concrete underneath it.

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