Ceiling insulation, recommended for staying cool?

[banagan]

Hi, I assumed adding 150cm thick ceiling insulation would help keep a condo cool, but not so sure after this 7 year old thread, http://bit.ly/2M6Vwbv (thought it best to start a new one)

 

So, I'm having an old condo renovated. Top floor, so about 5 feet from my ceiling to the condo ceiling. I'd like to keep the place cool and save on ac electric bills.

 

Should I install 150cm stay cool ceiling insulation? 

[CharlieH]

I did and it knocked my A/C usage down and av.temp  in house down by 4 deg.

 

Full thread on it here.....

 

 

[geoffbezoz]

Amassing stuff this insulation but surprised given the climate that it is not standard everywhere as there is a payback.  Having said that they are a bit slow in excepting new ideas from foreigners arn't they ? Wasn't it a mere  4000 odd years ago that the Egyptians used straw in their villas (the rich ones) to insulate them ?

[Artisi]

 bear in mind it works in both directions - slows heat into the living space and slows heat getting back out. 

[banagan]

9 minutes ago, Artisi said:

 bear in mind it works in both directions - slows heat into the living space and slows heat getting back out. 

Yes, I've been reading up on that. Apparently you need to vent the attic space properly... not exactly sure how to achieve that on a condo. I can't go adding vents to the condo roof... any ideas? Maybe Homepro can offer suggestions?

[banagan]

Read through CharlieH's previous thread, a lot more to ceiling insulation than I thought. I've still not clear on a few things, hope you guys can clear em up. My roof pics below.

1. I only need to lay the insulation on my ceiling? The roof above it is the condo roof (top floor)

2. The parts of the ceiling that is support beams, do I need to insulate that? If so, maybe 2 inch would fit... 

3. What's all this talk of fans, vents? Do people have fans blowing in the loft space? Or vents on the main roof?

4. I imagine Homepro do this all the time. Good idea to have them out to access? I believe they do that, right? I'm looking at close to 11k's worth insulation.

Thanks.

 

 

[tjo o tjim]

The insulation and radiant barrier is a good start, but you might look at taping the insulation (per manufacturer instructions, depending on type, etc) to give yourself a bit of a vapor barrier.  The latent heat load (de-humidification) can really dominate the costs of comfort cooling. 

[Artisi]

ideally, there should be insulation under the roof sheet to reduce the radiant heat entering the roof space.

Best to be reduced the heat at its source rather than trying to treat it later. 

 

putting a thick layer of insulation on top of the ceiling lining will turn the room into hot box as there is nowhere for any heat that finally get thru' the insulation to get back out again. Solution might be to put a few vents or fan in the ceiling  to exhaust any heat back into the roof space.

[bankruatsteve]

Looks like you will want to do that sooner than later.  Doesn't seem to be much space above the hangers to do it after the ceiling installed.  (?)

[sometimewoodworker]

2 hours ago, tjo o tjim said:

The insulation and radiant barrier is a good start

There is no radiant barrier installed and it's a bit too late to do it now.

[Artisi]

19 hours ago, banagan said:

Yes, I've been reading up on that. Apparently you need to vent the attic space properly... not exactly sure how to achieve that on a condo. I can't go adding vents to the condo roof... any ideas? Maybe Homepro can offer suggestions?

"Maybe Homepro can......" 

I wouldn't rely on Homepro for a technical assessment of the current time, even if they were wearing a watch. 

[tjo o tjim]

3 hours ago, sometimewoodworker said:

There is no radiant barrier installed and it's a bit too late to do it now.

The insulation pictured has an integral radiant barrier by the looks of it. Getting a vapor barrier to be solid would be a significant challenge though. 

[Artisi]

Banagan, have you considered spray on insulation to the underside of the roof sheet,  3 advantages, ideal insulation, reduces the possibility of leaks, and good sound proofing. 

 

 

 

22 hours ago, banagan said:

Yes, I've been reading up on that. Apparently you need to vent the attic space properly... not exactly sure how to achieve that on a condo. I can't go adding vents to the condo roof... any ideas? Maybe Homepro can offer suggestions?

 

[MikeN]

8 hours ago, Artisi said:

putting a thick layer of insulation on top of the ceiling lining will turn the room into hot box as there is nowhere for any heat that finally get thru' the insulation to get back out again. Solution might be to put a few vents or fan in the ceiling  to exhaust any heat back into the roof space.

"Turn it into a hot box "?  strange that when I did it in my house in Australia no such thing happened....even when it was hotter than it is here in Thailand. If it is insulated where does your heat come from ? Hot air from an open window ?...keep the window closed and the hot air outside.

[sometimewoodworker]

15 hours ago, tjo o tjim said:

The insulation pictured has an integral radiant barrier by the looks of it. Getting a vapor barrier to be solid would be a significant challenge though. 

No it does not. As the installation will not get hot.

 

A radiant barrier reduces radiation transfer from a hot surface. This is governed by the second law of thermodynamics.

 

You are mistaken, the installation has a reflective barrier.

 

Like many people you seem to have mistaken the fact that silver (coated aluminium) foil can be used as a reflective barrier, though it is only really effective as a radiant barrier, in the case of that insulation its a reflective not radiant barrier.

 

The reason is that used as a reflective barrier it almost always has dust accumulation on its surface (it is usually horizontal) . Whereas used as a radiant barrier dust can't be deposited in more than an extremely light amount, since it is inverted and on the underside of the roof.

 

NB this is Thailand, hot outside cooler inside, not a theoretical arctic environment, thought even there the same problems are in effect.

 

here is a fun and accurate explanation 

 

 

 

[banagan]

Let there be insulation! 

 

Asked my brother who's a builder, about fans, barriers etc, he said it's fine to just lay this stuff. 

[superal]

On 8/9/2019 at 11:11 AM, Artisi said:

ideally, there should be insulation under the roof sheet to reduce the radiant heat entering the roof space.

Best to be reduced the heat at its source rather than trying to treat it later. 

 

putting a thick layer of insulation on top of the ceiling lining will turn the room into hot box as there is nowhere for any heat that finally get thru' the insulation to get back out again. Solution might be to put a few vents or fan in the ceiling  to exhaust any heat back into the roof space.

I came to this topic as where I live has the too hot problem . The house belongs to my lady and was built 15 years ago . The roof is the corrugated cement board laid bare to the support steel work .  An apex roof which is quite high to the ridge , say 3.5 mtrs . The ceiling is suspended foam tiles  and the floor to ceiling height is 2.8 mtrs . There is no insulation in the loft . The house is like a greenhouse heat wise and even in the mornings when I come from my air con bedroom it is still 30c .  I go outside to cool down  . Roof size is 24 x 12  x 3.5 mtrs high . Have to say that the cement boards are not in the best of condition and we have 2 or 3 leaks in torrential rain . Each gable end has a small louvre vent which cannot be doing much. Because of the suspended ceiling wires I think it would not be easy to lay thick insulation . 

Any thoughts on the cheapest alternative . BTW yesterday the temperature inside the house was 35c and if I could get that down by 5c that would help .

Thinking , is that why we see many Thai houses have a roof on top of roof i.e. a double roof ?   

[masuk]

In Darwin, Australia, which is a pretty hot, tropical area, the recommended ceiling insulation of the fibre variety (used to be fibre glass but better stuff nowadays) is 150mm (NOT centimetres!)

 

In the olde worlde language, 15cm (150mm)  is 6 inches.

 

Australian Standards - Fletcher Insulation

 

https://insulation.com.au/support-article/australian-standards/

Jan 20, 2016 - There are a range of Australian Standards relevant to insulation, some of which include: AS/NZS 4859.1:2002 – Materials for the thermal insulation of buildings. AS 3999-2015 – Thermal insulation of dwellings – Bulk insulation – Installation requirements.

[masuk]

22 hours ago, superal said:

I came to this topic as where I live has the too hot problem . The house belongs to my lady and was built 15 years ago . The roof is the corrugated cement board laid bare to the support steel work .  An apex roof which is quite high to the ridge , say 3.5 mtrs . The ceiling is suspended foam tiles  and the floor to ceiling height is 2.8 mtrs . There is no insulation in the loft . The house is like a greenhouse heat wise and even in the mornings when I come from my air con bedroom it is still 30c .  I go outside to cool down  . Roof size is 24 x 12  x 3.5 mtrs high . Have to say that the cement boards are not in the best of condition and we have 2 or 3 leaks in torrential rain . Each gable end has a small louvre vent which cannot be doing much. Because of the suspended ceiling wires I think it would not be easy to lay thick insulation . 

Any thoughts on the cheapest alternative . BTW yesterday the temperature inside the house was 35c and if I could get that down by 5c that would help .

Thinking , is that why we see many Thai houses have a roof on top of roof i.e. a double roof ?   

Remember that ceiling cavity temps can be up to 70C.   The ceiling then radiates that heat into the room below.    If you can keep this heat out of the room, then it will stay close to the ambient air temperature.   Yes, lots of ventilation certainly helps.

 

The addition of rotary roof ventilators helps remove the heated air from the ceiling cavity.  These spin around with the hot air escaping.

 

[spidermike007]

I added insulation of R-22 and it made a big difference. House is cooler and when AC is turned off rooms stay cool for hours afterwards. Could not ventilate the attic without cutting through a wall, so decided not to. Still made a huge difference and cost was minimal. 13,000 baht including a laborer we hired. Really made the house alot more livable. The ceiling is now 4 degrees cooler and the house at least 2-3 degrees. 

[superal]

29 minutes ago, masuk said:

Remember that ceiling cavity temps can be up to 70C.   The ceiling then radiates that heat into the room below.    If you can keep this heat out of the room, then it will stay close to the ambient air temperature.   Yes, lots of ventilation certainly helps.

 

The addition of rotary roof ventilators helps remove the heated air from the ceiling cavity.  These spin around with the hot air escaping.

 

Thanks Masuk ,

                      Suspended ceiling poses a problem with the hanging wires and then there are the electrical cables which are tight and cannot be lifted for insulation to go under as I know to lay on top of cables is asking for trouble . I have considered the sprayed foam under the roof which would solve the leaks and give insulation but I think it is quite expensive . Any info from those who have used this method would be appreciated . The roof space is quite big and large enough to make an additional room by installing modified steel work .  This idea is common in the UK and a system of roof windows named " Velox " are installed but I have never seen them in Thailand . .

I am tempted to replace the suspended ceiling with a plasterboard hard ceiling , modify the wiring and then slab insulate over . Finally roof extractors named whirly ? , available as a solar powered item and not relying on the wind to work . Any opinions on this ?

[superal]

24 minutes ago, spidermike007 said:

I added insulation of R-22 and it made a big difference. House is cooler and when AC is turned off rooms stay cool for hours afterwards. Could not ventilate the attic without cutting through a wall, so decided not to. Still made a huge difference and cost was minimal. 13,000 baht including a laborer we hired. Really made the house alot more livable. The ceiling is now 4 degrees cooler and the house at least 2-3 degrees. 

R-22 ? I am not conversant with that . Where did you buy it from and did electric cables pose a problem ? Your ceiling is suspended type ? What is the area or size approx of your attic please ?

Thanks for your help 

[Iem]

I can see the gable end in the photos . I would have thought the answer would be to put a large expelair fan into the gable end ( above the ceiling insulation ) reducing the temperature in the roof space -as mentioned by someone else the temperature in this area , if not vented builds up . Regards , Iem

[4MyEgo]

On 8/13/2019 at 1:24 AM, banagan said:

Let there be insulation! 

 

Asked my brother who's a builder, about fans, barriers etc, he said it's fine to just lay this stuff. 

All due respect to your brother, you did say he is a builder, however insulation is a little bit of a different area.

 

After doing the below, the difference in degrees from outside to inside temperatures is 10 degrees, hard to believe, tested it 10 times, at different times of the day, it's like the air con is on, but its not, i.e. if it's 35 outside, its 25 inside, nice and we hardly turn on the air cons, at night, maybe for 20-30 minutes, then let the fan take over, rooms still stay cool throughout the night, and we have seen the difference in the drop in the electricity bills.

 

1) I had thermal reflective sisalation placed under my concrete roof tiles, which I purchased from HomePro, you can read up on it here: http://www.polynum-insulation.com/index.php?goto=bep

 

2) I then put in the R-38 insulation, remember, if you have downlights to cover them with something that will be elevated with a hole at the top of it, slightly above the height of the insulation, I used plastic pots with a hole at the bottom, but turned it upside down, and placed them over the downlight and its generator, this allows the heat out of the downlights and its generator, can't think of the generators correct name (sorry). 

 

3) You should have a good clearance up in the ceiling, e.g. at mid point I can stand and still have room above my head and I am 183cm in height.

 

4) I put those saloon door looking timber vents at the front gables, one double on both sides of the pitches and then places two whirly birds at the back and they spin all day long as this creates a sort of wind tunnel, e.g. If I stick my head up the manhole which is half way down, I will feel the immediate travel of hot air passing me and heading straight to the whirly birds. I also have vented eave covers 600mm x 900mm, I think you call them soffits ?

 

5) It pays to keep your windows closed and covered (clear) as a lot of heat travels in through your windows, whether it be trees or awnings or a something else like a shade cloth which we have also put up and big enough to cover the outside of 4 x 4 wall, which has cooled it down big time, e.g. you could put your hand on the wall inside and it was HOT, now it's luke warm, and very comfortable to sit in, it's my gym, and I rarely sweat in it since I put up the shade cloth ????

 

The more you do, the more you will cool your place, but just the R-38's won't do it, you will need the whirlybirds to extract the heat already in the ceiling when it builds up, i.e. it needs to get out and not stay in there, the thermal reflective sisalation can only hold the radiant heat for so long before it enters your ceiling space, same with the R-38's, and using something to extract the build up of heat within the ceiling plays a vital part of the process, whether its an extractor fan that kicks in at a particular time, or whirly birds, vents, and vented soffits, it's all going to help as well as keeping those windows covered, i.e. not allowing the sun to enter.

 

Sure it's going to cost, but it's the price you pay to stay comfortable in your castle if you spend as much time as I do on my rear ????

 

Good luck, hope some of this helps, as it has helped me, I swear by it !

 

 

 

[emptypockets]

On 8/8/2019 at 7:14 PM, geoffbezoz said:

Amassing stuff this insulation but surprised given the climate that it is not standard everywhere as there is a payback.  Having said that they are a bit slow in excepting new ideas from foreigners arn't they ? Wasn't it a mere  4000 odd years ago that the Egyptians used straw in their villas (the rich ones) to insulate them ?

I'm sure there will be one or two members who actually did that for the Egyptians and can confirm the prices too. 

[emptypockets]

On 8/12/2019 at 10:24 PM, banagan said:

Let there be insulation! 

 

Asked my brother who's a builder, about fans, barriers etc, he said it's fine to just lay this stuff. 

Ask an electrician and you may get a slightly different answer. 

[roath]

If you go to SCG (Siam Cement Group) store, they have installers who will recommend what you need and come and install for you.

 

There is a 2,000 charge for the inspection which can be set against any order made. They are probably a bit more expensive than a contractor but they are trained on how to install and offer a guarantee. Installation was about 5,000 baht for me for a 90 sq m attic (36 rolls of RT38). 

 

I also had roof vents installed. 

 

I've only just had it done, so I can't say whether it has made any difference as yet

[brianthainess]

On 8/8/2019 at 7:21 PM, Artisi said:

 bear in mind it works in both directions - slows heat into the living space and slows heat getting back out. 

Correct.

[brianthainess]

50 minutes ago, superal said:

Thanks Masuk ,

                      Suspended ceiling poses a problem with the hanging wires and then there are the electrical cables which are tight and cannot be lifted for insulation to go under as I know to lay on top of cables is asking for trouble . I have considered the sprayed foam under the roof which would solve the leaks and give insulation but I think it is quite expensive . Any info from those who have used this method would be appreciated . The roof space is quite big and large enough to make an additional room by installing modified steel work .  This idea is common in the UK and a system of roof windows named " Velox " are installed but I have never seen them in Thailand . .

I am tempted to replace the suspended ceiling with a plasterboard hard ceiling , modify the wiring and then slab insulate over . Finally roof extractors named whirly ? , available as a solar powered item and not relying on the wind to work . Any opinions on this ?

There is silver foil backed plasterboard available here. Also different thicknesses of silver insulation.

[emptypockets]

41 minutes ago, superal said:

R-22 ? I am not conversant with that . Where did you buy it from and did electric cables pose a problem ? Your ceiling is suspended type ? What is the area or size approx of your attic please ?

Thanks for your help 

The R22 that I know of is a refrigeration gas used in air conditioners and widely banned in the West as a greenhouse gas.