Polystyrene plates for ceiling insulation?

[Phil Conners]

The big supermarket chains have these largish polystyrene plates, maybe 100 x 70 cm or so. either about 1.5 or 3 cm thick. I was wondering if anyone tried using these for roof insulation, i.e. put them on top of the gypsum ceiling? I don't mean to make a 100% coverage, but even dropping a bunch of the plates on top of the gypsum surely must reduce temperatures with a bit, no? Considering the low price of these plates, I think they're only like 20 baht or so per plate, so even a one degree change would be worth the effort.

[Crossy]

Better get one and apply a match (outside of course), we wouldn't want your attic to get very hot due to a small electrical incident becoming a big conflagration

[Phil Conners]

Oh, right, polystyrene burns really well, forgot about that.

Why isn't rockwool available in Thailand?

[cooked]

If I were to use this I would put it on the underside of the ceiling. Fireproof PS or equivalent is available in Europe...maybe here also somewhere.

[IMHO]

Oh, right, polystyrene burns really well, forgot about that.

Why isn't rockwool available in Thailand?

if by rockwool you mean fiberglass insulation batts, they are available everywhere... But if shopping for building supplies at a supermarket, you're in the wrong place LOL.

In answer to your first question - No, a few randomly placed insulators won't do much at all for cooling - if the air can get around/under it, it's game over.

Edited October 3, 2013 by IMHO

[Khun Jean]

I had great success by using a combination of two styles of insulation and a fan.

The first was the bubble foam with aluminum foil. I placed this directly under the roof, about 5-10cm from the tiles/roof material. Air between roof and this foil gets hot and needs to be vented of. The roof has some vents on the highest points to allow that. This is by convection only.

The bubble foam acts as a radiation shield. This alone dropped the air temperature between the roof and ceiling about 15 degrees!

Then on top of the ceiling a 5cm layer of glasswool. These can be bought on rolls where the glasswool is inside aluminum foil. These can be taped together to prevent gaps.

The air between the roof and ceiling is then pulled out with a fan, effectively dropping the temperature to ambient.

The insulation on the ceiling is a barrier between that ambient temperature and the cooled area in the room. This is noticeable as the aircon cools it down quicker and is active much less resulting in much lower electricity usage. Of course stopping the cool air escape under the doors was also part of that, together with making sure windows and doors close very well.

The next step would be double glazed windows, but for now it is more then satisfactory.

[Phil Conners]

Hm that is interesting. I've never seen rockwool or glasswool here, neither in shops or actually used anywhere. Anyone know where that can be bought in the Pattaya area, and what is the cost? What about pests (rats, birds, snakes, insects), will they not nest in it?

[Khun Jean]

Bought everything at Thai Watsadu (http://www.thaiwatsadu.com/location.html), the one close to Ikea.

Rats,birds and snakes can be prevented by using a barrier.

I spend around 4000 baht 1 large roll of bubble foam and 8 rolls of glasswool, it covers 30m2.

[yankee99]

Hm that is interesting. I've never seen rockwool or glasswool here, neither in shops or actually used anywhere. Anyone know where that can be bought in the Pattaya area, and what is the cost? What about pests (rats, birds, snakes, insects), will they not nest in it?

Home pro and home works both sell the insulation. 2.4 sqm (one roll) are 399baht ..... Does anyone consider the weight on the ceiling?

[Phil Conners]

I had great success by using a combination of two styles of insulation and a fan.

The first was the bubble foam with aluminum foil. I placed this directly under the roof, about 5-10cm from the tiles/roof material. Air between roof and this foil gets hot and needs to be vented of. The roof has some vents on the highest points to allow that. This is by convection only.

The bubble foam acts as a radiation shield. This alone dropped the air temperature between the roof and ceiling about 15 degrees!

Then on top of the ceiling a 5cm layer of glasswool. These can be bought on rolls where the glasswool is inside aluminum foil. These can be taped together to prevent gaps.

The air between the roof and ceiling is then pulled out with a fan, effectively dropping the temperature to ambient.

The insulation on the ceiling is a barrier between that ambient temperature and the cooled area in the room. This is noticeable as the aircon cools it down quicker and is active much less resulting in much lower electricity usage. Of course stopping the cool air escape under the doors was also part of that, together with making sure windows and doors close very well.

The next step would be double glazed windows, but for now it is more then satisfactory.

How do you fix the bubble/alu foil 5-10cm from the tiles? Photos? I already have a whirlybird, it works as it should, rotates fast, but I don't feel much difference from before we had it installed.

I don't think it's good to have glasswool inside alufoil, it would make it very difficult to make a tight fit. I used to do some work with glasswool in Denmark many many years ago, I recall it is very very easy to work with, just cut up to fit. And wear old clothes and take a long shower after, that stuff itches!

Bought everything at Thai Watsadu (http://www.thaiwatsadu.com/location.html), the one close to Ikea.

Rats,birds and snakes can be prevented by using a barrier.

Thanks, I'll check it out. Never saw it before but they might just not have it on display, not like it is very interesting to look at, I guess

What is a barrier? Do you mean by closing all holes into the roof area? I think that's virtually impossible, rats and snakes will always find a way in if they want. I've never had problems with it but I know people who have.

Home pro and home works both sell the insulation. 2.4 sqm (one roll) are 399baht ..... Does anyone consider the weight on the ceiling?

I don't think it's heavy enough to make a problem for the ceiling, at least not mine.

Is it safe to leave cables and stuff directly on glass wool?

[Khun Jean]

How do you fix the bubble/alu foil 5-10cm from the tiles? Photos? I already have a whirlybird, it works as it should, rotates fast, but I don't feel much difference from before we had it installed.

I bought the cheap aluminum profiles that are used to hang ceilings and created in essence a second 'ceiling'.

The roof is under full sunshine and the roof material are thin concrete plates. They get extremely hot. Having only a small gap reduces the amount of air that gets hot and the aluminum foil gets only warm itself. Removing the air between roof and the foil is essential otherwise the foil becomes the new radiant.

I don't think it's good to have glasswool inside alufoil, it would make it very difficult to make a tight fit. I used to do some work with glasswool in Denmark many many years ago, I recall it is very very easy to work with, just cut up to fit. And wear old clothes and take a long shower after, that stuff itches!

I actually liked the glasswool inside alufoil better. Used aulminum tape to tape them together. No gaps at all. And i really like to prevent handling glasswool directly.

What is a barrier? Do you mean by closing all holes into the roof area? I think that's virtually impossible, rats and snakes will always find a way in if they want. I've never had problems with it but I know people who have.

I used the wrong word. I mounted a steel mesh material in the vent holes and used expanding foam to fill big gaps and covered it with a layer of cement.

One other step i am considering is to paint the roof with a heat reflecting paint. Just have to find someone who will scrape the roof clean first.

Edited October 5, 2013 by Khun Jean

[krisb]

Forget using these polystyrene things you found op. They won't do anything but they will help burn the house down very well. Just get normal insulation batts. Theres a few varieties, rockwool, fibreglass and tontine. Tontine is by far the most user friendly. It is the same stuff inside of pillows. It does'nt make you itchy to install like the others will.

[The Deerhunter]

I have similar plans for my wife's house inland from Chonburi. I am scared of polystyrene because of flammability. Glass wool is real glass melted & spun. Rockwool is real basalt rock melted & spun. Glasswool sandwiched between ali-foil sounds convenient as glass-wool "bats" are nasty to handle.

Does anyone know anything about rats, ants, termites, snakes etc response to polyester wool (Tontine??) or glass wool re nesting & breeding-in etc?

I was thjinking of using foil glass sandwich stapled to inside the bare "boxes" of the upstairs wall areas which is not lined yet, then possibly cutting polyester squares to fit the squaresand then lining with plasterboard. A suspended ceiling I will have to get someone in to do. That would be beyond me.

Is polyester wool (Tontine) flammable or flame-retardant-treated? I guess it would have to be, surely?

[krisb]

Tontine is the best imo. Not what you would call flammable. It's used through out the world. Easily installed. If you do use it, here's a trade secret. Tontine tears easily along the grain. It does'nt the other way. So the secret is use a serated bread knife and it cuts beautifully!

The deerhunter, be extremely careful if you intend stapling alfoil insulation to anything inside walls and ceilings if the powers connected. There have been several deaths in Australia from doing this. As for anything eating or nesting in tontine, sure it's possible. I mean it's warm and probably feels safe to vermin so probably no different than any other insulation in that respect. Respirator mask should still be worn while installing tontine.

Edited October 17, 2013 by krisb

[The Deerhunter]

The deerhunter, be extremely careful if you intend stapling alfoil insulation to anything inside walls and ceilings if the powers connected.

Thanks for the help on OP's posting. Re stapling: Upstairs is not lined so I would be stapling into studs, nogs & cladding i.e., bare visible wood frame and external cladding, prior to installing plasterboard lining. All wiring would be visible. Thanks for advice re respirator though. Yeah, Thai electrics scare me. This house is old school & there are no earth wires from what I can see!!!!!!!!!! However, I can see the value in a plastic (not steel) handled stapler!!!!!!!!!! Could get used somewhere else later. Ouch! Thanks for that tip!!!

Are any of the insulation materials considered "unfriendly" to pests? Is there any ant or termite baits worth including before the plasterboard goes on the inside?

[krisb]

Deerhunter, there are no baits as you put it that I''ve ever heard of. Preventative measures is the angle I'd go for. That's about it and hope they don't get in. Not using timber in the first place is a good start.

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