I was wondering if anyone has experience at applying roof insulation.
Our house is new, a bungalow with 2 bedrooms. The builder seems to have laid roof tiles on what look like asbestos sheets. I dont know how effective this will be at keeping the heat out.
I have seen adverts in Pattaya property magazines for foam insulation which is sprayed-on to the underside of the roof. I have not seen mention of uk-style rockwool insulation which would be laid on the ceiling. I believe the rockwool would be much cheaper but does it exist in LOS? Would it have other disadvantages ie nesting place for creepy-crawlies?...we do have aircon in one bedroom.

The foam is also a waterproofing coat and will effectively stick to the roof material. I am planning to do a similar project on the family house in Nong Khai at some point mainly to fix current and potential leaks

ash

Check this site Cool Thai House for all sorts of info. on building in LOS.

This is an Australian site greenhouse. gov. which is very good on many aspects of house design in hot climates.

Regarding spray on roof insulation - it has a very bad reputation in the UK, as it can cause all sorts of problems with damp/condensation. Not sure what its performance is like in LOS. We had the silver foil put in under the roofing when our house was built.

As for bulk insulation material - check out the Aussie site above for guidence.

quote:

we do have aircon in one bedroom.

So, unless you have an en-suite toilet you will roast like a duck when you go for a midnight wee wee

Remember, the heat inside the house will always be much the same as the ambient temperature in the shade outside. The sun heats up the windows, the walls and the ground surrounding.....also remember that hot air rises, it will get up there anyway, one of the best recommendations that I have seen, is to make sure you have a good vent at one end of the roof (those louvre door sort of things) and have a large pad lom at the other end.

Hi Pgcon,

I too have been through similar thought dilema's on this subject in the past, especially with the new house I built in Buriram after living just outside Pattaya for 5 years.

I had friends and neighbours in Pattaya who have one or the other and I listened to the pro's and con's from each. My conclusions were basically that if you are going to apply insulation, well you apply it to the underside of the roof. If applied typically like UK, ceiling joists, welll the heat comes through the roof and causes melt down in the roof space, and yes I mean melt-down!!

The roof foam is heavily advertised and as I think Ash mentioned, as well as insulation, well it is also promoted as a waterproof agent and also in helping entry of creepy crawlies etc!! However it is expensive (80K to 100K for an average size 3 bedroom bungalow) and if you ever have a broken roof tile for instance, well there will be quite a difficulty replacing it, as it is cemented into the foam.

After listening to much advice, I went the way that Thaddeus suggests, large ventilation louvres at either end of the roof apexes and 3 large wind operated pad loms in the main roof angles. I will try and attach a couple of pic's that I have in my comp. Unfortunately I am in my Dubai office at the moment, otherwise I would walk outside and be more accurate. Maybe attach via a couple of mails....Hope this helps...RayBan

Insertion of the back wind fan.

I forgot to say in my original reply that all 3 are now operational, cost about 3k each for purchase and installing and also extremely effective. If the roof space is kept cool, the house stays cool.

This is the best I can come up with in regards to a pic of the final installation, as I said I am in my Dubai office. This was actually a shot of the new outside kitchen I just built for Sanan, but top left you can see the rear roof fan.

All 3 fans have been installed since January, major rainy season in Buriram up to now this year, no roof leaks from the installation if installed professionally, (not Uncle Liang!!!).....

Having read some of the links, well this task is looking more complex than it at first appeared
Some contributors insist that the transfer of heat from the roof to the room below is due largely to radiation.
Insulating the ceiling or evacuating hot air from the roof space will only reduce heat transfer by convection.
So, radiation is reduced by radiating the heat back to the roof ie reflective material attached to the underside of the roof or laid on the loft-side of the ceiling.
Retro-fitting reflective layers to the underside of the roof....this requires two layers and what to fix it to?? They suggest taking the roof off first. Not really helpful.But placing it on the upper side of the ceiling would be quite easy. I guess I could do a trial on just one bedroom and measure temperature effect.
Anyone any experience of reflective layer technology? Apparently the material is available at HomeMart/HomePro.

quote:

Remember, the heat inside the house will always be much the same as the ambient temperature in the shade outside.

Hi again pgcon,

A reply eloquently put from possibly a person from an engineering background, but I wish to draw your attention to a quote from Thad's reply .

I am from a process engineering background and although your comments about heat radiation and convection are quite accurate, you forgot to mention the most important element of heat transfer in most Farang built Thai houses.........Conduction!!!!

Radiation from the sun's rays, convection from the wind etc, but most of the heat in one's home is retained via conduction to the roof tiles, which pass it on to the metal roof supports and associated ceiling supports, all usually metal. There is nothing in the natural world that can retain and conduct heat more than man made roof tiles and metal, we use it every day in industry to control heat exchange.

The ultimate source and objective of an engineer on this subject is to control the raw elements of heat and cooling by natural means, i.e. the sun's rays and the cooling affect of natural draft, both go hand in hand and are the most cost effective methods of heating and cooling.

Without using artificial means you will never reduce the temperature in your house below shade temperature (as per Thad's quote) without "constant cost" assistance. Newton's fundamental "Law of Resistances in Heat" will defeat you otherwise.

Try to use nature to serve your requirements as best as possible, on approaching retirement these laws of physics become quite a money saving way to go!!!

There is an ad in todays Bangkok Post for roof insulation and waterproofingAlso serves against unwanted vermin.Burglars trying to find their way in through the roof would need a sledgehammer now.
Company is called LOHR Trade and Consulting Pts.,Ltd.
Have branches in Bangkok,Pattaya and Udon Thani/Khon Kaen.
Website is given as
http://www.1stplanet.com/lohr-trade.
Don't know anything about roof insulation but may be of use.

quote:

Remember, the heat inside the house will always be much the same as the ambient temperature in the shade outside.

That is correct, although I would use the word temperature rather than heat.

However a point worth considering is the heat retaining effect of the mass of concrete in the uninsulated walls and roof of a Thai house. Long after the temperature has decreased outside after dusk, you may still be feeling the heat radiated from your concrete walls and roof.

A good practice is to shade the walls and roof if possible with natural shade, possibly from planting trees or building near existing natural shade. Even buying on the shady side of the street works - I know that is true, because that is what we did.

Does anyone know where you can buy the expanding foam in Udon or khon Kaen. Its available in the UK at B&Q but I've not seen in in the hardware stores in LOS.

We want it to insulate and seal the upstairs which my idiot brother in law forgot to overlap the timbers so when they dried they cracked and now leak.

Also can you buy silicone sealant ?

Cheers
ash

Hi Ash,

I have actually seen it in LOS, in Pattaya, but I cannot remember whether it was in the big Home Mart store on Sukhumvit, or in Home Pro at Carrefore. I will be trevelling up there next month and will keep my eye out for you........cheers.......RayBan

quote:

Does anyone know where you can buy the expanding foam in Udon or khon Kaen. Its available in the UK at B&Q but I've not seen in in the hardware stores in LOS.

I'll have a look next time I'm in Global House. That's about the biggest place in Khon Kaen, there's one in Udon Thani too.

Paul/Rayban

Much appreciated I would appreciate an idea of the price and if possible the brandname in thai (or english).

Cheers
ash