My house is being built in a village by a developer. to keep the attic cool i have reflective foil at the roof. I then asked [extra] for R-19 insulation at the ceiling. the contractor then brought R-23 with foil on each side, not what i wanted. i sent it back.

question is, if i did install the foil wrapped insulation at the ceiling line wont that trap moisture?. when i build in america we either put R-30 at the ceiling line or foil on the roof and paper backed R-19 at the ceiling, paper to the living side, which is proper and works well.

thanks for any input

Jimmy

What is the reflective foil UNDER the roof reflecting?

Also, I think the R-23 was just fine in the ceiling; if a leak develops the foil can keep the insulation from getting wet. In the states the only thing I've seen under the outer layer of roofing material (shingles or whatever) is a felt paper which comes in different "weights". I think it's purpose is to offer a moisture barrier to protect the decking (plywood) under it in case any slight leaks develop; also it offers some sound-proofing.

I'm not a roofer/builder so the above may be totally wrong; so be warned.

The 'foil' on the underside of the roofing, which is usually reflective on one side only, is generally used as a vapour barrier & not such a good insulator. In Australia, this stuff is called sarking.

Fibreglass 'bats' that have foil on one side are used as combination vapour barrier & insulation. There is an ongoing debate about the installation of vapour barriers with respect to the Northern Hemisphere & the Southern Hemisphere.

These things have been discussed at length on Thaivisa previously but I can't tell you where to find the topic.

My house is being built in a village by a developer. to keep the attic cool i have reflective foil at the roof. I then asked [extra] for R-19 insulation at the ceiling. the contractor then brought R-23 with foil on each side, not what i wanted. i sent it back.

question is, if i did install the foil wrapped insulation at the ceiling line wont that trap moisture?. when i build in america we either put R-30 at the ceiling line or foil on the roof and paper backed R-19 at the ceiling, paper to the living side, which is proper and works well.

thanks for any input

Jimmy

Jimmy,

you forgot one important feature which i mentioned when we met some time ago. it is most important to ventilate your attic, if possible force ventilated and not by wind-driven toys. no matter what foil you fix under the roof tiles -which initially might prevent some radiation- there will be heat building up in your attic. the double backed insulation available in Thailand works quite well but is difficult to apply because of the suspenders on which the gypsum ceilings are fixed. ideal would be the blown in insulation (U.S. style) which unfortunately is not available locally.

to solve the above-mentioned problem i had a steel mesh welded on top of the suspenders and therefore an even and "undisturbed" surface area to install the insulation mats.

off topic: when i returned from Brazil i found my fish pond with algae greener and most probably thicker than green pea soup. have an appointment today with a contractor to install inline UV in order to kill algae.

Hey

Just as a side note.

In Florida they have now changed the building code to make it against code to use ridge vents, you can now only use 'off' ridge vents.

You may want to incorporate these when doing the forced ventilation for the loft.

Kind regards

Peter

The point of ceiling insulation is to trap the heat that comes through the roof and keep it in the attic. So you have a layer of foil on top of the ceiling tar sheet to reflect the heat back to the roof.

Under the aluminium foil you will have a tar sheet. This absorbs some of the heat that gets through the aluminum sheet. It seems in Thailand they use other materials instead.

The point of ceiling insulation is to trap the heat that comes through the roof and keep it in the attic. So you have a layer of foil on top of the ceiling tar sheet to reflect the heat back to the roof.

Under the aluminium foil you will have a tar sheet. This absorbs some of the heat that gets through the aluminum sheet. It seems in Thailand they use other materials instead.

Steve,

no tar sheets, no plywood and no shingles in Thailand (as in the Greatest Nation on Earth™). moreover, a tar sheet is not capable of absorbing any heat and one wouldn't want to trap heat anywhere but try each and everything to get rid of the heat.

My house is being built in a village by a developer. to keep the attic cool i have reflective foil at the roof. I then asked [extra] for R-19 insulation at the ceiling. the contractor then brought R-23 with foil on each side, not what i wanted. i sent it back.

question is, if i did install the foil wrapped insulation at the ceiling line wont that trap moisture?. when i build in america we either put R-30 at the ceiling line or foil on the roof and paper backed R-19 at the ceiling, paper to the living side, which is proper and works well.

thanks for any input

Jimmy

Jimmy,

you forgot one important feature which i mentioned when we met some time ago. it is most important to ventilate your attic, if possible force ventilated and not by wind-driven toys. no matter what foil you fix under the roof tiles -which initially might prevent some radiation- there will be heat building up in your attic. the double backed insulation available in Thailand works quite well but is difficult to apply because of the suspenders on which the gypsum ceilings are fixed. ideal would be the blown in insulation (U.S. style) which unfortunately is not available locally.

As you suggested I bought a "whole house fan" which i going into my ceiling to pull heat out the the house when i get home. same setup i had in hawaii.

to solve the above-mentioned problem i had a steel mesh welded on top of the suspenders and therefore an even and "undisturbed" surface area to install the insulation mats.

They were planning on installing something to keep the insulation off the recessed lights since i dont have "IC" lights as i did in america which allow the insulation to touch the lighting

off topic: when i returned from Brazil i found my fish pond with algae greener and most probably thicker than green pea soup. have an appointment today with a contractor to install inline UV in order to kill algae.

Call me and I can help, you need the following

1. UV light properly sized

2. a true "koi approved" filter running 24-7

3. better circulation in the pond

4. no more than 30% sun on the water

5. minimul amout of feeding

thanks for your help

Jimmy

Hey

Just as a side note.

In Florida they have now changed the building code to make it against code to use ridge vents, you can now only use 'off' ridge vents.

You may want to incorporate these when doing the forced ventilation for the loft.

Kind regards

Peter

i wonder what sense that makes. anyway, each and every county in Florida has different codes. some of these codes are ridiculous. i took Volusia County Building Department (DeLand) to court because of their request that my ducts for the three central aircon units should be ABOVE and NOT BURIED in the insulation. naturally i won the case but the inspectors tried to give me a hard time for each and everything else, such as minimum center distance between a toilet and bidet, exhaust duct from kitchen not through attic and roof but sideways through walls. i was just laughing and so was my lawyer. we were relaxed as my german "judicial insurance" paid for each and every injunction or letter the lawyer wrote.

Hey

Just as a side note.

In Florida they have now changed the building code to make it against code to use ridge vents, you can now only use 'off' ridge vents.

You may want to incorporate these when doing the forced ventilation for the loft.

Kind regards

Peter

My guess is that this is because of the hurricanes they have there.....which we don't have in Thailand...if I'm right then this should be ignored for construction in Thailand unless someone can come up with some reason why ridge vents (properly designed and constructed of course) should not be used.

Chownah

Hey

The reason for the Unified Building Code change in Florida, was to stop ingress of water at wind speeds of over 40 mph. Apparently, it had been under discussion for several years and when the Unified Code was updated again after the 2004 Hurricanes, they included the Roof Vent amendment.

When I build my next home, wether in the USA, Thailand or anywhere where Negative/Forced Pressure Ventilation is being used, I will only be using off ridge vents.

Although each county can add to the Unified Building Code, they cannot make it less effective.

The strictest code is Miami-Dade County and most components are certified to that Code and then can be used anywhere in Florida.

Kind regards

Peter

I am having a house built. 80 meters

The builder wants to use this foil under the roof for about 8,000.

I would prefer, and would not mind paying the extra 4,000 for the 3 inch insulation that goes on the ceiling.

I do not care how hot the attic is. I care about the house. I have painted roofs white before, and it works great. I have also put a large industrial fan in the roof to blow hot air out of the atic to the outside of the house. Removing the bathroom access panel allows air to pass through the windows, through the house and up through the access way in the bathrooms and into and out of the attic in the evenings.

I like how this has worked.

Does the foil under the roof really help?

I do not care how hot the attic is. I care about the house.

if your attic is hot and your ceilings are not insulated your house will be hot. as simple as that.

Removing the bathroom access panel allows air to pass through the windows, through the house .. I like how this has worked.

of course this works... if one likes the bathroom "scent" in the house (especially after they have been used).

The reason for the Unified Building Code change in Florida, was to stop ingress of water at wind speeds of over 40 mph. Apparently, it had been under discussion for several years and when the Unified Code was updated again after the 2004 Hurricanes, they included the Roof Vent amendment.

thanks for the clarification Peter. i was not aware of that change. sold my home in Central Florida end of may 2004.

I am having a house built. 80 meters

The builder wants to use this foil under the roof for about 8,000.

I would prefer, and would not mind paying the extra 4,000 for the 3 inch insulation that goes on the ceiling.

I do not care how hot the attic is. I care about the house. I have painted roofs white before, and it works great. I have also put a large industrial fan in the roof to blow hot air out of the atic to the outside of the house. Removing the bathroom access panel allows air to pass through the windows, through the house and up through the access way in the bathrooms and into and out of the attic in the evenings.

I like how this has worked.

Does the foil under the roof really help?

We have just had the Home Pro 6" thick foil covered fibreglass laid on our ceiling boards...big big improvement..the wire supports proved a bit of a problem, as did the lights. However theory says that the insulation should touch the ceiling boards..no gap.

Having a ventilated roof aswell would improve things even more.

For more info type 'cool thai house' in google

Edited March 25, 200719 yr by John45

I had a building that got so hot, you could not go in there during the afternoons. After insulating, it was as cool as a wine celler.

Put the vapor barrior against the inside walls/ceiling.

Ventilate the roof.

Plant trees.

We have just had the Home Pro 6" thick foil covered fibreglass laid on our ceiling boards...big big improvement..the wire supports proved a bit of a problem, as did the lights. However theory says that the insulation should touch the ceiling boards..no gap.

For a small additional cost you could buy two thinner layers of fiberglass and lay them cross hatched. The thinner blankets are easier to handle and tuck around the wire supports and the cross hatching reduces the chances of gaps between the rolls.

I am having trouble find r-19 insulation. The only thing i have found so far is R-12 & R-23? and both are wrapped with foil. Expensive and not needed. i would like to have R-19 with one side vaper barriered. [in US we call it paper backed]. does anyone know where i can get it in pattaya without being foil wrapped?

My ceiling already has foil at the roof plane, two large wind turbines and a "whole house fan" at the ceiling level. I want this additional insulation at the ceiling level.

thanks Jimmy

i have looked at variouse places including Home Mart and Home west

A friend of mine built a big house near Jomtien. He is firm believer in insulation. He had the underside of his tile roof sprayed with foam as well as fiberglass in the ceiling. He says the foam was quite expensive but had benefits besides insulating. It keeps the roof tiles tight and eliminates any leaks. He used the superblock. That's the ones with foam in the center. Not only that, he put double block walls with an airspace between them. He has now moved in and he is very pleased with the results. He told me today that it cools even easier than he had expected.

"I do not care how hot the attic is. I care about the house."

***if your attic is hot and your ceilings are not insulated your house will be hot. as simple as that.

YOu missed this note: "I would prefer, and would not mind paying the extra 4,000 for the 3 inch insulation that goes on the ceiling."

Removing the bathroom access panel allows air to pass through the windows, through the house .. I like how this has worked.

"of course this works... if one likes the bathroom "scent" in the house (especially after they have been used). "

*** The air goes from the windows through the house into the bathroom and up through the access panel to the attic, not the other way around.

A friend of mine built a big house near Jomtien. He is firm believer in insulation. He had the underside of his tile roof sprayed with foam as well as fiberglass in the ceiling. He says the foam was quite expensive but had benefits besides insulating. It keeps the roof tiles tight and eliminates any leaks. He used the superblock. That's the ones with foam in the center. Not only that, he put double block walls with an airspace between them. He has now moved in and he is very pleased with the results. He told me today that it cools even easier than he had expected.

I considered several alternatives; sprayed or injected PU foam, sprayed cellulose fiber insulation, fiberglass in foil bags etc. Did some materials tests, checked prices with different suppliers etc.

Conclusion: there are many suppliers of PU foam, but most PU foam available on the market here has no noticeable fire protection / fire resistance. I would not want to have that in my house as a small fire will spread very rapidly in this. I lit a match next to a one year old sample (so any solvent residue etc should have evaporated) and it immediately ignited and gave off nasty smelling black smoke.

I came across one supplier who claims their PU foam is fire resistant but I was not able to get a price quote or materials sample from them.

Although it has a higher R value than fiberglass all suppliers who gave a quote quoted per square meter, and not for the volume of PU foam actually used. I wanted a volume quote as the final thickness applied is very important.

Cellulose fiber appears to have inferior insulation properties, and the one supplier I contacted couldn't be bothered to reply to email.

Fiberglass in foil bags - this is what I am going for. Good insulating properties, cheap, durable, insect and moisture proof as long as the foil bags are intact. Does not burn very well. Note that there are two types of foil bags; real aluminium foil bags and metalized plastic. The real foil costs a few baht more per bag but will last longer than the metalized plastic. I would not want to use fiberglass here unless in a sealed bag as condensation in the fiberglass turns it from insulation to a heat conductor.

Final price paid: B290 per pack for 3" (60cm x 4m) and B440 per pack for 6".

Will post a re-evaluation in this thread in 30 years, or whenever I come across a problem with the fiberglass insulation (whichever comes first).

Lingling,

Are you sure that the fibres in the bag are glass fibres....I've seen fiber mat insulation in bags that is not glass at all but some fire "resistent" plastic fibre.

Chownah

Edited March 29, 200719 yr by chownah

Are you sure that the fibres in the bag are glass fibres....I've seen fiber mat insulation in bags that is not glass at all but some fire "resistent" plastic fibre.

I hope it is, but to be honest I didn't do the same fire-test with this one as I did with the PU foam. This is the one I got:

http://www.siamfiberglass.com/final/produc...tion/house.html

"LoveDaBlues" Wrote

"What is the reflective foil UNDER the roof reflecting?"

HEAT! And very very well.

If you are open minded on the subject of insulation, I can describe a simple test you can do so you can see if it works yourself.

Conductive insulation (ie.e non conductive - foam, fibreglass, etc) is hardly necessary in Thailand. unless in the North where it can get cool.

Copied from

http://www.insulco.com.au/foils.htm

"It is important to note that the only time you are able to install foils as a sarking under roofs and in wall frames, is during construction – so you need to plan ahead. Insulco also have specialised perforated foils available for use on glasswool products for industrial, air conditioning and acoustic systems.

benefits at a glance

* Provides the ideal insulation system for the control of heat and condensation.

* Reflects radiant heat away from living areas in summer when installed adjacent to an air space.

* Suitable to be used under all types of roofs as weatherproof sarking underlay.

* Provides an impermeable vapour barrier when combined with bulk insulation and the ends are sealed.

* All Insulco foils comply with the Australian Standards."

We sprayed the foam type insulation on the under side of the roof, metal sheet, last week. So we will see how this works as i have never used it before.

The point about the aluminum is that it reflects the heat back up to the roof. Standard in South Asia is to have a layer of tar sheet on top of the ceiling and then the aluminium on top of that. I'd check it out as its easy to lay, and easy to replace.

Theirs a company in bangkok CoolandCosy, that comes from Australia and suposedly has the best insulation for tropical climates. I know two families that have used them and it can be 36 outside and 26 indoors without air. Unfortunately I do not have their phone number.

Barry

Theirs a company in bangkok CoolandCosy, that comes from Australia and suposedly has the best insulation for tropical climates. I know two families that have used them and it can be 36 outside and 26 indoors without air. Unfortunately I do not have their phone number.

Barry

my respect and congratulations to this company! seems to me that they invented the perpetuum mobile and at the same time solved the mathematical task of the circle quadrature.

who said miracles do not happen nowadays?