Ceiling Insulation - Worth the cost?

[chiang mai]

If you look very closely at the claims made by roof paint manufacturers you'll see that they are all untrue, the paint in itself doesn't have the ability to reflect heat, only changing the colour will do that. Even the properties of paint technology that is claimed to have been used on the space shuttle is exaggerated, ceramic paint doesn't reduce heat it evens out the absorption of heat, the underlying insulating tiles on the SS prevent heat penetration.

[rjcampbe]

Is there any basis for the Thai opinion that "no need" insulation?

the only downside is the ignorance of Thai builders!

Exactly the same attitude as Thai "electricians" have about the Earth wire... "No need..."

[Thorgal]

One of the heat problems you probably can't solve, especially if the house doesn't have a radiant barrier between the roof tiles and the steel in the roof, is the conducted heat transfer of heat from the roof tiles, to the steel in the roof, to the walls below, it can be a significant problem evidenced by hot walls near the ceiling, in late after noon. Think of the steel in your roof as being the same as a heating element in your kettle, unless you can find a way to break that transfer your living space will get warm because it can't be insulated against.

Spraying ~5cm PU foam reduces only +/-10% of heat but keeps your roof wind and waterproof.

All roof tiles splices are sealed. Which will result in reducing mold creation if you want to install additional insulation panels to result in desired temperature.

I would rather start like OP's bungalow to apply PU foam first. Prices in Thailand start around 700THB/m2 and drops for larger surfaces. Most of these all-in companies are runned by Farangs who will give you detailed expertise and calculation for additional insulation.

Just an example : http://www.sprayfoamthailand.com/heatinsulation/

Each roof insulation depends on sizing, location (humidity), previous used construction materials for the roof and below., etc..

None of them are explained in OP...

Edited June 5, 2016 by Thorgal

[bazza40]

I installed batts that were approx 100 mm thick with foil on top. Helped significantly but I noticed after approx 5-7 years that the batts have compressed down to about half thickness of what they were originally. I think this is from the high humility here. I'm sure they still are offering some reduction in heat but obviously not as much as when first installed.

Possibly your batts have not compressed, they have collapsed.

Fibreglass is manufactured to many different specifications. The more reputable manufacturers use borate salts as a

flux. Less reputable ones use sodium which in a humid environment will leach out of the glass more readily, leaving a fragile silicate structure. It also depends on how much binder ( usually phenol or urea formaldehyde resin ) is used to stick the fibres together, A lot of variables in there.

[bazza40]

Spraying ~5cm PU foam reduces only +/-10% of heat but keeps your roof wind and waterproof.

All roof tiles splices are sealed. Which will result in reducing mold creation if you want to install additional insulation panels to result in desired temperature.

I would rather start like OP's bungalow to apply PU foam first. Prices in Thailand start around 700THB/m2 and drops for larger surfaces. Most of these all-in companies are runned by Farangs who will give you detailed expertise and calculation for additional insulation.

Just an example : http://www.sprayfoamthailand.com/heatinsulation/

Each roof insulation depends on sizing, location (humidity), previous used construction materials for the roof and below., etc..

None of them are explained in OP...

ImageUploadedByThaivisa Connect1465104391.951575.jpgImageUploadedByThaivisa Connect1465104403.386093.jpg

PU foam is one of the most dangerous materials one can use in a housing structure, nearly as risky as asbestos.

In the event of a fire, the combustion products include hydrogen cyanide - the same compound formerly used in gas chamber executions in the USA.

[masuk]

Is there anyone in the Chiang Rai area who knows how to retrofit roof vents? I'm convinced our roof space is a mass of heated air.

Insulation definitely helps, provided the roof is adequately vented.

AGREED!

First step should be the installation of a "Cyclone" type roof ventilator.

Some people think they're electric powered. No so, the hot air escaping out causes the vent to rotate.

https://www.google.com.au/search?q=cyclone+roof+vents&biw=1745&bih=1026&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwiS6emYm5DNAhVMrY8KHYSTBOIQsAQIXA&dpr=0.9

[BuriramDevelopers]

It depends, generally it works and will save you money. But if you have nice insolation , bu these crappy , bad fitting wood frames round your windows........get my point?

But yes it works and in the long run will be saving you money

[sometimewoodworker]

Spraying ~5cm PU foam reduces only +/-10% of heat but keeps your roof wind and waterproof.

All roof tiles splices are sealed. Which will result in reducing mold creation if you want to install additional insulation panels to result in desired temperature.

I would rather start like OP's bungalow to apply PU foam first. Prices in Thailand start around 700THB/m2 and drops for larger surfaces. Most of these all-in companies are runned by Farangs who will give you detailed expertise and calculation for additional insulation.

Just an example : http://www.sprayfoamthailand.com/heatinsulation/

Each roof insulation depends on sizing, location (humidity), previous used construction materials for the roof and below., etc..

None of them are explained in OP...

ImageUploadedByThaivisa Connect1465104391.951575.jpgImageUploadedByThaivisa Connect1465104403.386093.jpg

PU foam is one of the most dangerous materials one can use in a housing structure, nearly as risky as asbestos.

Complete FUD and BS

In the event of a fire, the combustion products include hydrogen cyanide - the same compound formerly used in gas chamber executions in the USA.

While that is true you have left out the fact that all products that contain nitrogen will produce hydrogen cyanide, that PU foam produces less than most, that hydrogen cyanide is combustible so is often degraded by the fire that produced it and finally that in a fire it's unlikely to be that that hurts you

Hydrogen cyanide is a by-product of the combustion of materials used in products used in everyday life (insulation, carpets, clothing, and synthetics). The culprit is nitrogen. Nitrogen gas in atmospheric air can contribute (under the right circumstances) to the formation of minute amounts of cyanide during combustion. High temperatures and low-oxygen concentrations favor the formation of cyanide gas. Smoke from the combustion of grass clippings, green wood, tobacco, cotton, paper, wool, silk, weeds, and animal carcasses will likely contain some hydrogen cyanide gas. But the real offender is the combustion of manmade plastic and resins containing nitrogen, especially if the fire is hot and in an enclosed space. Common manmade materials that generate cyanide gas during combustion include nylon, polyurethane, melamine, and acrylonitrile.

[F4UCorsair]

A whirlybird on the roof, taking the hot air from the ceiling cavity, will make a greater difference, and that's based on personal experience.

Reflective foil under the tiles and a whirlybird are a better combination than batts, imo, but batts will prevent cool air being transferred through the ceiling to the roof cavity, so provide some benefit.

Use a multi pronged approach, whirlybird, foil and batts, none of them will break the bank.

Thanks to all the home builders sharing their experience. I'm not experienced in building, but just trying to use common sense. Have installed the aluminum sheeting under the tiles and that was cheap. Will also have passive vents in attic, but haven't seen a whirlybird in the stores. This is where the Thais say enough. But my thought is that ceiling insulation will keep the air con in and reduce cooling costs in the same way it keeps the heat in in cold climates. The combo of aluminum under the tiles to keep the heat out and fiberglass on the ceiling to keep the cool in seems to make sense. The stay cool isn't cheap but isn't prohibitive either. Also using roof overhangs and trees for shading seems a good idea.

Interesting the several comments that insulation slows cooling the house at night. But hopefully the air con will take care of that.

Opening windows will take care of that, but if you've been running the aircon during the day, inside will already be cooler than outside.

[bazza40]

Spraying ~5cm PU foam reduces only +/-10% of heat but keeps your roof wind and waterproof.

All roof tiles splices are sealed. Which will result in reducing mold creation if you want to install additional insulation panels to result in desired temperature.

I would rather start like OP's bungalow to apply PU foam first. Prices in Thailand start around 700THB/m2 and drops for larger surfaces. Most of these all-in companies are runned by Farangs who will give you detailed expertise and calculation for additional insulation.

Just an example : http://www.sprayfoamthailand.com/heatinsulation/

Each roof insulation depends on sizing, location (humidity), previous used construction materials for the roof and below., etc..

None of them are explained in OP...

ImageUploadedByThaivisa Connect1465104391.951575.jpgImageUploadedByThaivisa Connect1465104403.386093.jpg

image.jpg

Hydrogen cyanide is a by-product of the combustion of materials used in products used in everyday life (insulation, carpets, clothing, and synthetics). The culprit is nitrogen. Nitrogen gas in atmospheric air can contribute (under the right circumstances) to the formation of minute amounts of cyanide during combustion. High temperatures and low-oxygen concentrations favor the formation of cyanide gas. Smoke from the combustion of grass clippings, green wood, tobacco, cotton, paper, wool, silk, weeds, and animal carcasses will likely contain some hydrogen cyanide gas. But the real offender is the combustion of manmade plastic and resins containing nitrogen, especially if the fire is hot and in an enclosed space. Common manmade materials that generate cyanide gas during combustion include nylon, polyurethane, melamine, and acrylonitrile.

I think what you have quoted supports my argument it's a serious risk. It's also a matter of surface area. A entire roof covered in PU foam is going to have a very fast rate of spread compared to a pile of grass clippings, not so?

Incidentally, try a little courtesy in your postings. You may be talking to someone who knows a lot more about a subject than you do.

[manfredtillmann]

One of the heat problems you probably can't solve, especially if the house doesn't have a radiant barrier between the roof tiles and the steel in the roof, is the conducted heat transfer of heat from the roof tiles, to the steel in the roof, to the walls below, it can be a significant problem evidenced by hot walls near the ceiling, in late after noon. Think of the steel in your roof as being the same as a heating element in your kettle, unless you can find a way to break that transfer your living space will get warm because it can't be insulated against.

Spraying ~5cm PU foam reduces only +/-10% of heat but keeps your roof wind and waterproof.

All roof tiles splices are sealed. Which will result in reducing mold creation if you want to install additional insulation panels to result in desired temperature.

I would rather start like OP's bungalow to apply PU foam first. Prices in Thailand start around 700THB/m2 and drops for larger surfaces. Most of these all-in companies are runned by Farangs who will give you detailed expertise and calculation for additional insulation.

Just an example : http://www.sprayfoamthailand.com/heatinsulation/

Each roof insulation depends on sizing, location (humidity), previous used construction materials for the roof and below., etc..

None of them are explained in OP...

ImageUploadedByThaivisa Connect1465104391.951575.jpgImageUploadedByThaivisa Connect1465104403.386093.jpg

never seen anything like this - but it looks cool and totally intriguing.

a few things that come to mind:

application hazards - this stuff is bound to be toxic to inhale or to absorb through skin - what blowing agents are used? cfc's? are the thai applicators fully trained, use personal protective gear and apparatus?

how does one inspect structural roof members for decay or termite infestation? the outer roof cover will still emit moisture and insects - you just can't see them no more.

how toxic is this stuff in case of a house fire? will you kill all your neighbors if your chips boil over?

is there an environmentally sound way of separating it from the building when it comes to demolition? or will it all just all get dumped into the river for some other nation to worry about it - like everything else here?

i suppose that's why i have never seen this...

[bazza40]

Spraying ~5cm PU foam reduces only +/-10% of heat but keeps your roof wind and waterproof.

All roof tiles splices are sealed. Which will result in reducing mold creation if you want to install additional insulation panels to result in desired temperature.

I would rather start like OP's bungalow to apply PU foam first. Prices in Thailand start around 700THB/m2 and drops for larger surfaces. Most of these all-in companies are runned by Farangs who will give you detailed expertise and calculation for additional insulation.

Just an example : http://www.sprayfoamthailand.com/heatinsulation/

Each roof insulation depends on sizing, location (humidity), previous used construction materials for the roof and below., etc..

None of them are explained in OP...

ImageUploadedByThaivisa Connect1465104391.951575.jpgImageUploadedByThaivisa Connect1465104403.386093.jpg

never seen anything like this - but it looks cool and totally intriguing.

a few things that come to mind:

application hazards - this stuff is bound to be toxic to inhale or to absorb through skin - what blowing agents are used? cfc's? are the thai applicators fully trained, use personal protective gear and apparatus?

how does one inspect structural roof members for decay or termite infestation? the outer roof cover will still emit moisture and insects - you just can't see them no more.

how toxic is this stuff in case of a house fire? will you kill all your neighbors if your chips boil over?

is there an environmentally sound way of separating it from the building when it comes to demolition? or will it all just all get dumped into the river for some other nation to worry about it - like everything else here?

i suppose that's why i have never seen this...

CFC's are banned as blowing agents for PU foams by the Montreal Protocol on ozone-depleting chemicals. However, both China and Russia never signed off on the protocol. Thailand? depends on where the PU comes from,I suppose.

The most common blowing agents nowadays are short chain aliphatics such as pentane and hexane, highly flammable. Petrol sniffing is quite popular in some communities.

Doubt if you'd kill your neighbours. However,if you are still inside your life expectancy is very low.

[manfredtillmann]

Spraying ~5cm PU foam reduces only +/-10% of heat but keeps your roof wind and waterproof.

All roof tiles splices are sealed. Which will result in reducing mold creation if you want to install additional insulation panels to result in desired temperature.

I would rather start like OP's bungalow to apply PU foam first. Prices in Thailand start around 700THB/m2 and drops for larger surfaces. Most of these all-in companies are runned by Farangs who will give you detailed expertise and calculation for additional insulation.

Just an example : http://www.sprayfoamthailand.com/heatinsulation/

Each roof insulation depends on sizing, location (humidity), previous used construction materials for the roof and below., etc..

None of them are explained in OP...

ImageUploadedByThaivisa Connect1465104391.951575.jpgImageUploadedByThaivisa Connect1465104403.386093.jpg

never seen anything like this - but it looks cool and totally intriguing.

a few things that come to mind:

application hazards - this stuff is bound to be toxic to inhale or to absorb through skin - what blowing agents are used? cfc's? are the thai applicators fully trained, use personal protective gear and apparatus?

how does one inspect structural roof members for decay or termite infestation? the outer roof cover will still emit moisture and insects - you just can't see them no more.

how toxic is this stuff in case of a house fire? will you kill all your neighbors if your chips boil over?

is there an environmentally sound way of separating it from the building when it comes to demolition? or will it all just all get dumped into the river for some other nation to worry about it - like everything else here?

i suppose that's why i have never seen this...

CFC's are banned as blowing agents for PU foams by the Montreal Protocol on ozone-depleting chemicals. However, both China and Russia never signed off on the protocol. Thailand? depends on where the PU comes from,I suppose.

The most common blowing agents nowadays are short chain aliphatics such as pentane and hexane, highly flammable. Petrol sniffing is quite popular in some communities.

Doubt if you'd kill your neighbours. However,if you are still inside your life expectancy is very low.

thank you

[chiang mai]

Is there anyone in the Chiang Rai area who knows how to retrofit roof vents? I'm convinced our roof space is a mass of heated air.

Insulation definitely helps, provided the roof is adequately vented.

AGREED!

First step should be the installation of a "Cyclone" type roof ventilator.

Some people think they're electric powered. No so, the hot air escaping out causes the vent to rotate.

https://www.google.com.au/search?q=cyclone+roof+vents&biw=1745&bih=1026&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwiS6emYm5DNAhVMrY8KHYSTBOIQsAQIXA&dpr=0.9

And they are only effective if a significant source of cooler air is allowed in to replace the hotter air that is vented, otherwise it will not spin and simply becomes a hole in the roof for air air to rise out of occasionally, that's why people put fans inside them, to make them spin, duh! The two ports, the point where the hot air is pushed out and the other, the point where cooler air is brought in to replace it, must be sized properly. In the case of vented soffits (for cooler inbound air) and gable vents (for exhausted hot air), the two must be the same size otherwise the smaller of the two opening will limit the amount of ventilation, e.g. 5 square feet of outbound ventilation and 3 square feet of inbound means you have three square feet of ventilation in your roof space. In the case of a whirly bird roof vent the calculation becomes more difficult because the outbound capacity is variable based on turbine speed, which in turn is dictated by the size of the inbound cooler air vents. Clear?

Edited June 5, 2016 by chiang mai

[F4UCorsair]

A whirlybird on the roof, taking the hot air from the ceiling cavity, will make a greater difference, and that's based on personal experience.

Reflective foil under the tiles and a whirlybird are a better combination than batts, imo, but batts will prevent cool air being transferred through the ceiling to the roof cavity, so provide some benefit.

Use a multi pronged approach, whirlybird, foil and batts, none of them will break the bank.

Am constantly amazed seeing no ventilation of attic spaces being ventilated at all. That seems to be such a no-brainer but...

You are not trying to eliminate hot air from your roof cavity, you need to have a barrier to stop radiated heat whirly birds will not get rid of radiated heat. Extensively used in factories and buildings without ceiling cavities their main purpose is for ventilation.

Whirlybirds are effective in removing hot air from ceiling cavities. I can vouch for that.

Stopping radiated heat is another angle, just as batts are, stopping cooled air escaping through the ceiling.

No one method, in isolation, will achive best results.

Stop heat getting through the roof (foil), remove what does (whirlybirds), stop cooled air getting through the ceiling (batts), stop radiated heat (trees, roof overhangs, tinted windows).

[F4UCorsair]

Is there anyone in the Chiang Rai area who knows how to retrofit roof vents? I'm convinced our roof space is a mass of heated air.

Insulation definitely helps, provided the roof is adequately vented.

AGREED!

First step should be the installation of a "Cyclone" type roof ventilator.

Some people think they're electric powered. No so, the hot air escaping out causes the vent to rotate.

https://www.google.com.au/search?q=cyclone+roof+vents&biw=1745&bih=1026&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwiS6emYm5DNAhVMrY8KHYSTBOIQsAQIXA&dpr=0.9

And they are only effective if a significant source of cooler air is allowed in to replace the hotter air that is vented, otherwise it will not spin and simply becomes a hole in the roof for air air to rise out of occasionally, that's why people put fans inside them, to make them spin, duh! The two ports, the point where the hot air is pushed out and the other, the point where cooler air is brought in to replace it, must be sized properly. In the case of vented soffits (for cooler inbound air) and gable vents (for exhausted hot air), the two must be the same size otherwise the smaller of the two opening will limit the amount of ventilation, e.g. 5 square feet of outbound ventilation and 3 square feet of inbound means you have three square feet of ventilation in your roof space. In the case of a whirly bird roof vent the calculation becomes more difficult because the outbound capacity is variable based on turbine speed, which in turn is dictated by the size of the inbound cooler air vents. Clear?

Even if the whirlybird is powered, unless there is adequate incoming air from under the eaves, little will be achieved.

[chiang mai]

A whirlybird on the roof, taking the hot air from the ceiling cavity, will make a greater difference, and that's based on personal experience.

Reflective foil under the tiles and a whirlybird are a better combination than batts, imo, but batts will prevent cool air being transferred through the ceiling to the roof cavity, so provide some benefit.

Use a multi pronged approach, whirlybird, foil and batts, none of them will break the bank.

Am constantly amazed seeing no ventilation of attic spaces being ventilated at all. That seems to be such a no-brainer but...

You are not trying to eliminate hot air from your roof cavity, you need to have a barrier to stop radiated heat whirly birds will not get rid of radiated heat. Extensively used in factories and buildings without ceiling cavities their main purpose is for ventilation.

Whirlybirds are effective in removing hot air from ceiling cavities. I can vouch for that.

Stopping radiated heat is another angle, just as batts are, stopping cooled air escaping through the ceiling.

No one method, in isolation, will achive best results.

Stop heat getting through the roof (foil), remove what does (whirlybirds), stop cooled air getting through the ceiling (batts), stop radiated heat (trees, roof overhangs, tinted windows).

A minor point - cooled air doesn't escape through the ceiling, the hot air penetrates the ceiling (if it is not allowed to rise and escape) and warms the cooler air below, preventing (slowing actually) that penetration of the ceiling is what bat insulation is all about.

[F4UCorsair]

Technical question.......should the inlet/s for air to the cavity be greater or smaller in area than the outlets?

I know the answer, but seeing if anybody else does.

Quite right on that point CM, and I was trying to simplify it. In actual fact, air above the inside unit of an airconditioner will be warmer than that below because the thermostat is located in the case.

[chiang mai]

The outlet should be slightly larger because hot air expands.

[Naam]

tinted windows

are highly overrated. ideal are tinted windows/glass doors with a reflective mirror-like coating. paid an additional ~25% (glass only, not frames), and i'm very happy with the result.

[chiang mai]

I suppose the real advantage of PU foam is that it prevents heat radiation from the roof tiles onto the stonework and ceilings below, it is effectively a radiant barrier with a layer of insulation as well. But whilst it may stop radiant heat (heat that is stored in the roof tiles and reflected onto the ceilings below), it doesn't stop conducted heat transfer from the roof tiles to the steel in the roof which ultimately is tied to the walls of the living space. Also, the layer of insulation is quite thin hence it will be defeated quite quickly. All of that means that there is a lot of convected hot air in the roof space which has to be managed out. That seems like an expensive radiant barrier when there are much cheaper options available.

[F4UCorsair]

tinted windows

are highly overrated. ideal are tinted windows/glass doors with a reflective mirror-like coating. paid an additional ~25% (glass only, not frames), and i'm very happy with the result.

window.JPG

That's what I intended saying Naam, 'reflective coating' rather than 'tinted'. People selling the product call it 'tinting', but it's really a reflective coating, and it's very effective.

If a house had aluminium foil under the roof, batts in the ceiling, a whirlybird, and reflective coating on the windows, you could be in danger of freezing to death!!??

Edited June 6, 2016 by F4UCorsair

[eeeya]

my house had a serious heat issue even after installing foil backed insulation. Upstairs was unbearable and you would walk through a layer of heat as you came up the stairs.

After reading through posts on TV about reducing ambient inside temperature I used a multi pronged approach.

I installed 2 whirlybirds on the roof, 2 blower fans in the upstairs ceiling to suck hot air from the upstairs rooms into the roof cavity and increased outside roof ventilation to allow air into the roof cavity. Also used 3M film on the windows.

When asking for advice from the locals i got the usual "this is normal for thailand, people dont use upstairs in the day time." But I went in guns blazing and got it done after repeated pushing.

I originally had foil backed insulation only in the roof but daytime heat was still unbearable.

now the temperature of the upstairs level has dropped considerably. cost me about 20k all up.

Rainy season will be useful to prove everyone that whirlybirds dont leak (fingers crossed)

Edited June 6, 2016 by eeeya

[Naam]

That's what I intended saying Naam, 'reflective coating' rather than 'tinted'. People selling the product call it 'tinting', but it's really a reflective coating, and it's very effective.

If a house had aluminium foil under the roof, batts in the ceiling, a whirlybird, and reflective coating on the windows, you could be in danger of freezing to death!!??

freezing to death is not in the cards. but icicles developing on your balls and pecker are quite uncomfortable

[F4UCorsair]

That's what I intended saying Naam, 'reflective coating' rather than 'tinted'. People selling the product call it 'tinting', but it's really a reflective coating, and it's very effective.

If a house had aluminium foil under the roof, batts in the ceiling, a whirlybird, and reflective coating on the windows, you could be in danger of freezing to death!!??

freezing to death is not in the cards. but icicles developing on your balls and pecker are quite uncomfortable

And the greater the mass, the greater the discomfort.............so you shouldn't feel too much discomfort Naam!!

[sometimewoodworker]

Spraying ~5cm PU foam reduces only +/-10% of heat but keeps your roof wind and waterproof.

All roof tiles splices are sealed. Which will result in reducing mold creation if you want to install additional insulation panels to result in desired temperature.

I would rather start like OP's bungalow to apply PU foam first. Prices in Thailand start around 700THB/m2 and drops for larger surfaces. Most of these all-in companies are runned by Farangs who will give you detailed expertise and calculation for additional insulation.

Just an example : http://www.sprayfoamthailand.com/heatinsulation/

Each roof insulation depends on sizing, location (humidity), previous used construction materials for the roof and below., etc..

None of them are explained in OP...

ImageUploadedByThaivisa Connect1465104391.951575.jpgImageUploadedByThaivisa Connect1465104403.386093.jpg

image.jpg

Hydrogen cyanide is a by-product of the combustion of materials used in products used in everyday life (insulation, carpets, clothing, and synthetics). The culprit is nitrogen. Nitrogen gas in atmospheric air can contribute (under the right circumstances) to the formation of minute amounts of cyanide during combustion. High temperatures and low-oxygen concentrations favor the formation of cyanide gas. Smoke from the combustion of grass clippings, green wood, tobacco, cotton, paper, wool, silk, weeds, and animal carcasses will likely contain some hydrogen cyanide gas. But the real offender is the combustion of manmade plastic and resins containing nitrogen, especially if the fire is hot and in an enclosed space. Common manmade materials that generate cyanide gas during combustion include nylon, polyurethane, melamine, and acrylonitrile.

I think what you have quoted supports my argument it's a serious risk. It's also a matter of surface area. A entire roof covered in PU foam is going to have a very fast rate of spread compared to a pile of grass clippings, not so?

Not so, all PU used in roof insulation has flame retardant. So if you can get it burning (and almost everything will burn given enough heat and oxygen) then it not be the major danger and probably not a significant one either, as the rest of the house or roof will be burning long before that.

Incidentally, try a little courtesy in your postings. You may be talking to someone who knows a lot more about a subject than you do.

If you do, you have not demonstrated any of that knowledge in your post.

[bazza40]

I think what you have quoted supports my argument it's a serious risk. It's also a matter of surface area. A entire roof covered in PU foam is going to have a very fast rate of spread compared to a pile of grass clippings, not so?

Not so, all PU used in roof insulation has flame retardant. So if you can get it burning (and almost everything will burn given enough heat and oxygen) then it not be the major danger and probably not a significant one either, as the rest of the house or roof will be burning long before that.

Incidentally, try a little courtesy in your postings. You may be talking to someone who knows a lot more about a subject than you do.

If you do, you have not demonstrated any of that knowledge in your post.

If you were talking about PU foam in Western countries, you may be right. However, this is Thailand.

The most expensive flame retardants in PU foams are organic phosphates. As I've said before in this thread, boric acid as a flame retardant slowly diffuses from the insulation medium.

I would expect a considerable proportion of PU foam here to come from China. I think we all know the Chinese like to maximize profit. Regulation there is as lax as Thailand. Perhaps you can tell me how you can guarantee every PU roof application has an effective flame retardant in it.

[sometimewoodworker]

I think what you have quoted supports my argument it's a serious risk. It's also a matter of surface area. A entire roof covered in PU foam is going to have a very fast rate of spread compared to a pile of grass clippings, not so?

Not so, all PU used in roof insulation has flame retardant. So if you can get it burning (and almost everything will burn given enough heat and oxygen) then it not be the major danger and probably not a significant one either, as the rest of the house or roof will be burning long before that.

Incidentally, try a little courtesy in your postings. You may be talking to someone who knows a lot more about a subject than you do.

If you do, you have not demonstrated any of that knowledge in your post.

If you were talking about PU foam in Western countries, you may be right. However, this is Thailand.

The most expensive flame retardants in PU foams are organic phosphates. As I've said before in this thread, boric acid as a flame retardant slowly diffuses from the insulation medium.

I would expect a considerable proportion of PU foam here to come from China. I think we all know the Chinese like to maximize profit. Regulation there is as lax as Thailand. Perhaps you can tell me how you can guarantee every PU roof application has an effective flame retardant in it.

Why would I try to do that? Can you prove that they don't?

My PU foam chemicals came from Germany as did the chemicals for other installations I know of.

I do not know of any of Chinese origin, they may be used and they might be substandard.

So you are now basing your statement of the danger of PU foam on the use of incorrect materials. That makes your advice far less exciting doesn't it?

I stand by my statement that PU foam is no more a significantly dangerous producer of Hydrogen cyanide than wood and less than silk. [ironic mode]So don't use wood in your house or silk in your clothes of furnishings [/ironic mode]

[bazza40]

If you were talking about PU foam in Western countries, you may be right. However, this is Thailand.

The most expensive flame retardants in PU foams are organic phosphates. As I've said before in this thread, boric acid as a flame retardant slowly diffuses from the insulation medium.

I would expect a considerable proportion of PU foam here to come from China. I think we all know the Chinese like to maximize profit. Regulation there is as lax as Thailand. Perhaps you can tell me how you can guarantee every PU roof application has an effective flame retardant in it.

Why would I try to do that? Can you prove that they don't?

My PU foam chemicals came from Germany as did the chemicals for other installations I know of.

I do not know of any of Chinese origin, they may be used and they might be substandard.

So you are now basing your statement of the danger of PU foam on the use of incorrect materials. That makes your advice far less exciting doesn't it?

I stand by my statement that PU foam is no more a significantly dangerous producer of Hydrogen cyanide than wood and less than silk. [ironic mode]So don't use wood in your house or silk in your clothes of furnishings [/ironic mode]

Quote: "All PU used in roof insulation has flame retardant." A rather sweeping generalisation.

You can't prove that statement. I can't prove the converse without laboratory tests.. Doesn't really matter to me, PU roof insulation is never going to be used in a house I inhabit. That's based on product knowledge, as I was formerly a development chemist working on incorporation of flame retardants in PU foams.

I think the stuff's dangerous. You don't. Other viewers of this thread can decide for themselves.

As Emerson once said, a foolish consistency is the hobgoblin of small minds.

[siamcrut]

my house had a serious heat issue even after installing foil backed insulation. Upstairs was unbearable and you would walk through a layer of heat as you came up the stairs.

After reading through posts on TV about reducing ambient inside temperature I used a multi pronged approach.

I installed 2 whirlybirds on the roof, 2 blower fans in the upstairs ceiling to suck hot air from the upstairs rooms into the roof cavity and increased outside roof ventilation to allow air into the roof cavity. Also used 3M film on the windows.

When asking for advice from the locals i got the usual "this is normal for thailand, people dont use upstairs in the day time." But I went in guns blazing and got it done after repeated pushing.

I originally had foil backed insulation only in the roof but daytime heat was still unbearable.

now the temperature of the upstairs level has dropped considerably. cost me about 20k all up.

Rainy season will be useful to prove everyone that whirlybirds dont leak (fingers crossed)

Well done!

I had a similar situation. After cutting roof tiles to instal whirlybirds make sure it ain't leak in heavy rain!

I used some tarmac tape from Sika, on some roof tiles around the modifications!

No leaking at all!

Cheers.

http://tha.sika.com/en/group.html