Keeping the roof area cool

[IMHO]

Yep, the main benefit is minimizing thermal short circuits . The only way I can see to truly achieve the kind of effect in the image would be to heavily "sag" the foil between the trusses - without that you just have dozens of horizontal battens blocking airflow upwards..

Sorry IMHO, but now you disappoint me. How does the batten block the airflow under a curved roof tile? The flat side rests on the batten, while the curved side is completely unobstructed .

This is just a picture taken of the web, but in real life the curved part of the roof tile is even bigger than the flat part .

Fair call, but the popular curved tiles used in Thailand (Monier Elebana, V-Con etc) don't have anywhere near the gap that your photo has. Here's an actual photo I just took

Tile-Cline-Gap.jpg

Also, if you look at this, you'll see that whether the foil is on top of the batten, or under it, the gap remains the same (save a few microns), and that airflow gap is only about the thickness of the tile itself at the junction with the C-Line (batten).

I remain a proponent of foil under battens BTW, just sayin'

The picture of the tile was taken from the Monier website, so I assume that is how the gap from a Thai Monier tile looks

http://www.monier.in/roof-solutions/roof-ventilation.html

When you put the foil on top of the batten, There is no way to straighten the foil, and the wind will blow under the foil and push it towards the tile thereby blocking any airflow.

While where under the battens the foil can be straightened easily because the battens are screwed on top, and there is no way that the foil can blow upwards, because first of all the eaves opening are higher than the foil and the foils is stretched.

That means you don't save a few microns, but about 1 inch.

Not trying to be argumentative, but for wind to blow up the foil as per your imagined scenario, it'd need serious windspeed up that tiny little channel - decent quality foil is stiff enough to be formable, and it's anchored all over the place

As for the India Monier range, no idea. Only buy Thai made tiles.

The gap is more like 1/2 an inch at the apex BTW.

Edited July 2, 2014 by IMHO

[JesseFrank]

Sorry IMHO, but now you disappoint me. How does the batten block the airflow under a curved roof tile? The flat side rests on the batten, while the curved side is completely unobstructed .

This is just a picture taken of the web, but in real life the curved part of the roof tile is even bigger than the flat part .

Fair call, but the popular curved tiles used in Thailand (Monier Elebana, V-Con etc) don't have anywhere near the gap that your photo has. Here's an actual photo I just took

Tile-Cline-Gap.jpg

Also, if you look at this, you'll see that whether the foil is on top of the batten, or under it, the gap remains the same (save a few microns), and that airflow gap is only about the thickness of the tile itself at the junction with the C-Line (batten).

I remain a proponent of foil under battens BTW, just sayin'

The picture of the tile was taken from the Monier website, so I assume that is how the gap from a Thai Monier tile looks

http://www.monier.in/roof-solutions/roof-ventilation.html

When you put the foil on top of the batten, There is no way to straighten the foil, and the wind will blow under the foil and push it towards the tile thereby blocking any airflow.

While where under the battens the foil can be straightened easily because the battens are screwed on top, and there is no way that the foil can blow upwards, because first of all the eaves opening are higher than the foil and the foils is stretched.

That means you don't save a few microns, but about 1 inch.

Not trying to be argumentative, but for wind to blow up the foil as per your imagined scenario, it'd need serious windspeed up that tiny little channel - decent quality foil is stiff enough to be formable, and it's anchored all over the place

As for the India Monier range, no idea. Only buy Thai made tiles.

The gap is more like 1/2 an inch at the apex BTW.

I think you start showing yourself a bad loser now IMHO.

Everyone know that a Monier tile made in India is exactly the same as the one made in Thailand, the Philippines or Malaysia since they are the same company .

Foil, even the most decent one, is only 1 millimeter thick and need very little breeze to get moved. The only way to anchor it when under the tiles is with steel wires, which may even cause it to tear when trying to stretch it or just from the wind, something that isn't possible when it is locked under a batten.

I'm out of here, and I suggest you should stay in the automotive forum, instead of talking about things you have no idea about.

Because someone in your family is a builder and you do the accounting, doesn't make you knowledgeable about building

FYI , a batten is 30 mm high, with on top of that the tile gap.

Edited July 2, 2014 by JesseFrank

[IMHO]

I think you start showing yourself a bad loser now IMHO.

Everyone know that a Monier tile made in India is exactly the same as the one made in Thailand, the Philippines or Malaysia since they are the same company .

Foil, even the most decent one, is only 1 millimeter thick and need very little breeze to get moved. The only way to anchor it when under the tiles is with steel wires, which may even cause it to tear when trying to stretch it or just from the wind, something that isn't possible when it is locked under a batten.

I'm out of here, and I suggest you should stay in the automotive forum, instead of talking about things you have no idea about.

Because someone in your family is a builder and you do the accounting, doesn't make you knowledgeable about building

FYI , a batten is 30 mm high, with on top of that the tile gap.

Hey, hey there

Please do feel free to correct me when I'm wrong, but, I'm afraid my wife has the exclusive on correcting me when I'm right

[JesseFrank]

I think you start showing yourself a bad loser now IMHO.

Everyone know that a Monier tile made in India is exactly the same as the one made in Thailand, the Philippines or Malaysia since they are the same company .

Foil, even the most decent one, is only 1 millimeter thick and need very little breeze to get moved. The only way to anchor it when under the tiles is with steel wires, which may even cause it to tear when trying to stretch it or just from the wind, something that isn't possible when it is locked under a batten.

I'm out of here, and I suggest you should stay in the automotive forum, instead of talking about things you have no idea about.

Because someone in your family is a builder and you do the accounting, doesn't make you knowledgeable about building

FYI , a batten is 30 mm high, with on top of that the tile gap.

Hey, hey there

Please do feel free to correct me when I'm wrong, but, I'm afraid my wife has the exclusive on correcting me when I'm right

Fine, if you still consider yourself to be correct, then i challenge you to show us a link where is advised to put the foil between the batten and the roof tile as being insulation efficient.

And with a link I don't mean one from Somchai the builder or an " expert" on one or another forum, but a link from a credible company with a purpose of roof insulation in hot countries.

I'll take a chair because I guess it may take a while.

[IMHO]

Will this do?

[IMHO]

Even better, no Thai needed

[JesseFrank]

Will this do?

foil-install.jpg

Who is C-CO, another wanna be company that doesn't has a clue what it's talking about ?

Let me give you an example of what I have in mind that most companies in Thailand have not a clue what they are selling.

The biggest water purification company in Thailand, with some 2400 branches all over Thailand, sold me a 80 liter full automatic whole house water softener system.This system is sold in all the Home pro as well.

There system can only be programmed to regenerate the 60 liter of resin every 2 - 4 or maximum every 7 days. At the maximum setting of every 7 days that makes you need about 1200 Kg of salt a year to regenerate the resin.

When questioned they told me that is the normal way a water softener works. So you think they know what they are talking about ?

For your info, the regeneration of the resin is never time based but depends on the quantity of water and the hardness of the water that flows through it, but on an average household about every 120 days is more than sufficient.

I think the company in your picture is similar, otherwise why would it make a difference for insulation properies if the foil is under or on top of the battens, depending on the fact if the foil is laid downwards or sidewards ?

The only reason in my opinion that they suggest as on the package has nothing to do with insulation properties, but is that when laying sideways the only way to lock the foil is by sticking under the battens.

When laying downwards you can stick steel wire through the foil and wind it around the battens, which is more convenient.

So I'm still waiting for a link that advises to lay the foil on top of the battens, for insulation properties, and explains why.

[IMHO]

C-CO is made by SCG - same company that makes Tra Chang (Elephant brand in the video). And who also make Monier roof tiles under license ...

Edited July 2, 2014 by IMHO

[sotsira]

we are having AC installed too. but dont want to use it all the time, and would like way of dropping the temp by a few degrees if we can

You can't have it both ways, either design the attic to be efficient for the A/C, that means fully insulated from the main living area to prevent A/C air entering the attic.

or

Design the attic to allow air from the main living area to exhaust into the attic and then outside.

I would go with the first option if i were you, and vent the attic with airflow to keep it as cool as possible by installing soffit vents for intake and ridge vents for exhaust.