Thin Interior Wall Insulation (TIWI)

[iansale]

Hi all, new member on here. We have recently bought a detached Victorian house, recently well renovated however struggling with cold issues. Even with the full heating on full blast the main living spaces struggle to get above 12 degrees.

I got hold of a thermal camera and using that identified some draft proofing i can do. But the thing that stands out is how cold all the external walls are - around 4 degrees c, compared to 10 degrees for the floor, ceiling, double glazed windows.

I assume that means I should tackle the walls first as they are drawing the most heat?

If so next question is how to insulate... Can't do external as need to keep character of the building. And internally due to period fixtures and fittings putting 60-100mm of insulation will entail ripping out features... Which leads me to TIWI (Thin Internal Wall Insulation) which is a bit of a trade off. Says gets around 70% of the impact of full thickness insulation but at a width of only 10-20mm or so, so opens up possiblity of wall insulation with minimal disruption.

Has anyone used it? Would you recommend it? Know any installers? Or are there better alternatives?

See this government report on TIWI here : https://www.google.com/url?sa=t&sou...oQFnoECBAQAQ&usg=AOvVaw0ioChBTmsyLN0LykILoleK

Report from Leeds Uni : https://www.google.com/url?sa=t&sou...oQFnoECBEQAQ&usg=AOvVaw1xto0n4GK4ZSguZhAFMa5F

 

[a twig]

Has that been the case only in the recent cold snap or beforehand?

Generally something like that means one or a combination of:

1) Undersized heating system - can’t physically put enough heat into the house to get above 12
2) Howling draughts - hot air leaving faster than beating can warm up incoming cold air
3) Damp (sorry) - if walls are very cold, that’s often because they are damp, a water saturated wall takes a lot longer to warm up that a dry one (specific heat capacities and all that)

 

[iansale]

Has that been the case only in the recent cold snap or beforehand?

Generally something like that means one or a combination of:

1) Undersized heating system - can’t physically put enough heat into the house to get above 12
2) Howling draughts - hot air leaving faster than beating can warm up incoming cold air
3) Damp (sorry) - if walls are very cold, that’s often because they are damp, a water saturated wall takes a lot longer to warm up that a dry one (specific heat capacities and all that)

Appreciate the really rapid respose! Thanks. Its been particularly hard the last week with he -8C temp outside. But even when it was 4-5C we would struggle to get up to 15-16C inside. Gas bill getting pretty impressive.... heating om full power is about £3.60 an hour.

1) could be true, the living dining area is very big (50 square meters) but is only heated by two large radiators either end. A solution we are considering for this is installing underfloor heating to spread the heat around the room, and reduce cost per hour of heating (as boiler can be set much lower). Would you recommend wet UFH? We were thinking of maybe getting it across the bottom floor - around 100square meters, but due to staircases, cupboards kitchen pininsula etc we'd only cover around 66 sq m with the UFH.

2) The thermal camera reveals cold spots (catflap, fireplace, skirting, under doors, window cases) but nothing hugely noticable in terms of moving air. If you hover you hand over the area you can feel a very gentle movement but you have to be looking for it. I assume though over time the heat loss is probably quite significant so draft-proofing is key, so we are prioritising that.

3) I don't think we have damp at ground floor leve. No mould, wt patches, discolouring etc. We have got damp in the basement but you can see that it stops before moving above hip height. Will defo ask though when we get a contractor round. Any tests we should do ourselves?

Thank you! And would you say doing wall insulation is worth it? And is TIWI a good idea?

 

[Lacan07]

Hi all, new member on here. We have recently bought a detached Victorian house, recently well renovated however struggling with cold issues. Even with the full heating on full blast the main living spaces struggle to get above 12 degrees.

I got hold of a thermal camera and using that identified some draft proofing i can do. But the thing that stands out is how cold all the external walls are - around 4 degrees c, compared to 10 degrees for the floor, ceiling, double glazed windows.

I assume that means I should tackle the walls first as they are drawing the most heat?

If so next question is how to insulate... Can't do external as need to keep character of the building. And internally due to period fixtures and fittings putting 60-100mm of insulation will entail ripping out features... Which leads me to TIWI (Thin Internal Wall Insulation) which is a bit of a trade off. Says gets around 70% of the impact of full thickness insulation but at a width of only 10-20mm or so, so opens up possiblity of wall insulation with minimal disruption.

Has anyone used it? Would you recommend it? Know any installers? Or are there better alternatives?

See this government report on TIWI here : https://www.google.com/url?sa=t&sou...oQFnoECBAQAQ&usg=AOvVaw0ioChBTmsyLN0LykILoleK

Report from Leeds Uni : https://www.google.com/url?sa=t&sou...oQFnoECBEQAQ&usg=AOvVaw1xto0n4GK4ZSguZhAFMa5F

Hi all, new member on here. We have recently bought a detached Victorian house, recently well renovated however struggling with cold issues. Even with the full heating on full blast the main living spaces struggle to get above 12 degrees.

I got hold of a thermal camera and using that identified some draft proofing i can do. But the thing that stands out is how cold all the external walls are - around 4 degrees c, compared to 10 degrees for the floor, ceiling, double glazed windows.

I assume that means I should tackle the walls first as they are drawing the most heat?

If so next question is how to insulate... Can't do external as need to keep character of the building. And internally due to period fixtures and fittings putting 60-100mm of insulation will entail ripping out features... Which leads me to TIWI (Thin Internal Wall Insulation) which is a bit of a trade off. Says gets around 70% of the impact of full thickness insulation but at a width of only 10-20mm or so, so opens up possiblity of wall insulation with minimal disruption.

Has anyone used it? Would you recommend it? Know any installers? Or are there better alternatives?

See this government report on TIWI here : https://www.google.com/url?sa=t&sou...oQFnoECBAQAQ&usg=AOvVaw0ioChBTmsyLN0LykILoleK

Report from Leeds Uni : https://www.google.com/url?sa=t&sou...oQFnoECBEQAQ&usg=AOvVaw1xto0n4GK4ZSguZhAFMa5F

As Twig said I'd check the rads aren't undersized. Without being able to click on your links the only thing I would say is with insulation bulk matters and there's been various claims over the years for spacing saving materials that have been tested and proven to b *****KS. Over on the the Green building forum there's a whole thread ripping into the claims of silver foil insulation. It's amazing how popular the product is despite being proven to be useless. All I'd say is tread carefully.

 

[TudorCottage]

As has been said, check the efficiency of your current system first. How old is the boiler? Maybe a Chemical flush of the heating system is required, which will remove any air in the system at the same time. Do you have any cold spots on the radiators?

It wasn’t until we moved here that I realised how bad the system was in my last place, an old boiler that couldn’t cope with a big detached house, rads that just weren’t getting hot enough. I thought they were ok until I moved here and felt these!! Inefficiency was probably masked by better insulation than I have here.

If you do go down the underfloor heating route I would recommend a gas system, dearer than electric to install but I would imagine much cheaper to run. We have an electric underfloor system (radiators upstairs) and when cranked up it‘s nice and toasty, but eye watering costs to run.

It has been an exceptional cold period and these old places require a bit more juice to keep them warm. Our internal walls in the original cottage felt like the inside of a fridge, definitely not damp just freezing temperatures outside getting into the wall requiring a lot of heating to keep at bay. Whilst the cavity walls in the 1980’s and 2000’s extensions felt ok.

 

[malcolm]

I've just been around checking my place. I found my 9 inch brick walls tend to be about the same temperature or a little warmer than the new double glazed windows. It was a useful exercise as I found a radiator that wasn't supposed to be on. What are your walls made from? Do they have any paint/ render/ cement pointing that might be keeping them from drying out?

 

[Lacan07]

1) could be true, the living dining area is very big (50 square meters) but is only heated by two large radiators either end. A solution we are considering for this is installing underfloor heating to spread the heat around the room, and reduce cost per hour of heating (as boiler can be set much lower). Would you recommend wet UFH? We were thinking of maybe getting it across the bottom floor - around 100square meters, but due to staircases, cupboards kitchen pininsula etc we'd only cover around 66 sq m with the UFH.

My kitchen / diner is quite small, about 22 SQM and the BTU required is probably between 8000 - 9000, (with 40mm wood fibre IWI installed). You'd usually spread this over two radiators, the max BTU you can get from a rad is usually about 8000 I think.