Roof Insulation

[culicine]

Hi all, we are about to get some roof insulation done. We have basically narrowed it down to two choices. A polyethelene foam spray that is sprayed onto the underside of the tiles. The thickness should be about 2 inches. The other type is the square foam/aluminimum tiles that are placed onto the ceiling inside the roof. The cost will be similar for both. The tiles themselves are cheaper but labout cost will be an add on. The foam spray is about 430 baht per square metre.

Does anyone have comments regarding these two materials. Pros and cons?

In out last place we had some imported material from australia which worked great. It was like a gray duck down material (forgot its name), and was about 4-5 inches thich and put onto the ceiling inside the roof. That worked great, but have lost their phone number and the company name.

[wpcoe]

One "pro" that I've read about the foam spray-on insulation is that it secures your roof tiles. Apparently one somewhat common entry point for burglars is to remove roof tiles, but with the spray-on insulation, they essentially are glued into place.

[LennyW]

I have known some people to have condensation problems after they have applied the PU spray foam, must have a good airflow through your roof space.

[ad61]

The foam spray is a very good way to insulate your house, not only against the heat but it will also stop water to leak on to your ceilling as it is happen very often here in Thailand.

[longball53098]

Have you looked at and considered the fiberglass batts made by the Siam Cement Group? I believe the name is StayCool. It would lay down over the ceiling grid to a thickness of about 6 inches

[Rimmer]

Methinks you will get a lot more input if I move this to DIY lots of very knowledgeable folks over there.

[katabeachbum]

PU foam gives condense problems if your roof only has venting through roof bricks. any leak in roof bricks is discovered after corrosionproblems in your roof has come a long way. Does not withstand UV, so any sunshine coming through tiles will damage foam. Advantage is if your rooftiles are not tied, foam keeps them in position.

squeared foam/aluminum sheets or rolls keep the roof as it is. 5 mm insulates equal to 3 inches fiberglass, does not hold humidity and allows venting as before insullating. My favorite, but installation must be inspected to avoid gaps.

[Naam]

The foam spray is a very good way to insulate your house, not only against the heat but it will also stop water to leak on to your ceilling as it is happen very often here in Thailand.

the foam spray under the tiles is worth nothing and used nowhere on this planet except in Thailand by companies who want to make an easy and quick buck. all it does is slow down the heat built-up in the attic for a couple of hours. it is the attic heat which transmits rather easily through the gypsum ceilings when these boards are not insulated. insulated the ceilings is a bit tedious because of the suspensions holding up the gypsum boards but it pays.

an excellent solution is to use the foam ON the ceilings instead on the inside of the roof tiles and of course make sure that the attic is properly ventilated.

[katabeachbum]

The foam spray is a very good way to insulate your house, not only against the heat but it will also stop water to leak on to your ceilling as it is happen very often here in Thailand.

the foam spray under the tiles is worth nothing and used nowhere on this planet except in Thailand by companies who want to make an easy and quick buck. all it does is slow down the heat built-up in the attic for a couple of hours. it is the attic heat which transmits rather easily through the gypsum ceilings when these boards are not insulated. insulated the ceilings is a bit tedious because of the suspensions holding up the gypsum boards but it pays.

an excellent solution is to use the foam ON the ceilings instead on the inside of the roof tiles and of course make sure that the attic is properly ventilated.

good idea.

PUfoaming the ceilings 2 inches would make excellent insulation. some job to avoid or box in gypsum all the downlights though, and electric must have been installed in conducts to boxes over ceiling. not very common here

[culicine]

Thanks for the responses. We ended up getting some material (10 mm thick) that is in long rolls (website: m-pe.com). This is laid onto the ceiling and sealed with aluminium tape. The cost was about 22K with labour for about 75 sq m. Not bad. The foam material applied to the roof would have been about 50K. It seems to work quite well with an R value of about 13. Very little heat is coming though the ceilings now.

[katabeachbum]

Thanks for the responses. We ended up getting some material (10 mm thick) that is in long rolls (website: m-pe.com). This is laid onto the ceiling and sealed with aluminium tape. The cost was about 22K with labour for about 75 sq m. Not bad. The foam material applied to the roof would have been about 50K. It seems to work quite well with an R value of about 13. Very little heat is coming though the ceilings now.

sounds like a good and inexpensive solution. and your roof is still vented as it was

[jaideeguy]

Better hope that your ceiling is sealed against vermin.....rats, bats and gekos......they love the ready made homes with nice slick floors and ceilings and soft bedding of the fiberglass. Works for a year before the invaders move in and is a real mess to remove and dispose of.......my experience.

[Naam]

Better hope that your ceiling is sealed against vermin.....rats, bats and gekos......they love the ready made homes with nice slick floors and ceilings and soft bedding of the fiberglass. Works for a year before the invaders move in and is a real mess to remove and dispose of.......my experience.

geckos might make it but who has an attic with access big enough for rats or bats?

[Donnyboy]

Better hope that your ceiling is sealed against vermin.....rats, bats and gekos......they love the ready made homes with nice slick floors and ceilings and soft bedding of the fiberglass. Works for a year before the invaders move in and is a real mess to remove and dispose of.......my experience.

geckos might make it but who has an attic with access big enough for rats or bats?

you would be surprised how rats can gain access into ceiling spaces

[mdechgan]

The foam spray is a very good way to insulate your house, not only against the heat but it will also stop water to leak on to your ceilling as it is happen very often here in Thailand.

the foam spray under the tiles is worth nothing and used nowhere on this planet except in Thailand by companies who want to make an easy and quick buck. all it does is slow down the heat built-up in the attic for a couple of hours. it is the attic heat which transmits rather easily through the gypsum ceilings when these boards are not insulated. insulated the ceilings is a bit tedious because of the suspensions holding up the gypsum boards but it pays.

an excellent solution is to use the foam ON the ceilings instead on the inside of the roof tiles and of course make sure that the attic is properly ventilated.

I also recommend spraying insulation on the ceiling right above the gypsum boards. Usually it is about 10cm think. However it is pain if you have to rewire some lights or replace or cutout some drywall or lighting fixtures. I don't recommend sparying the tiles because it only slows down heat radiation and it doesn't insulate the ceiling or room.

[lioness]

Thanks for the responses. We ended up getting some material (10 mm thick) that is in long rolls (website: m-pe.com). This is laid onto the ceiling and sealed with aluminium tape. The cost was about 22K with labour for about 75 sq m. Not bad. The foam material applied to the roof would have been about 50K. It seems to work quite well with an R value of about 13. Very little heat is coming though the ceilings now.

Reply

I used this as well, the material cost was around 9,000 Baht and I laid it myself, it's been in for 5 years now and does a great job, together with ceiling fans I have never had to turn on the air conditioners.

[Hssl]

PU Foam spray has a major problem for low grade steel roof truss's - traps any moisture and the truss rust's from the inside out

If me i would

1 Vent the roof space

2 make sure i have sofit vents to stop pests entering the roof space

3 lag the roof with foil

4 lag the celling with rock wool / stay cool type lagging