How To Cool An Old Style House?

[akirasan]

Hey all,

We are in a traditional style old Thai house. It is on stilts with very thin wooden walls (I'm sure you know the type).

My problem with it is that it gets baking hot during the day, and I'm looking at ways to cool it down. My wife wants to get an air con but I want to try and get the house as cool as we can first of all.

I'm thinking of taking a 3 step approach, being:

1) Rebuild the roof - but what materials are the best? Currently it's a flat roof made out of corrugated tin. I also want to get some vents cut out to allow the air to flow through the space between the roofing layers.

2) Insulate the walls - which insulation is best for cooling? and is there any way to keep mice and rats from making a home in there? 

3) Shade the outside wall with trees - will take a couple of years to get big enough.

Does anyone have any other suggestions?

 

[worgeordie]

Yes do all 3, before installing A/c, having trees and water

helps a lot,that's what we have and don't have A/c,dont

like them.make sure any insulation is fire retardant.

regards Worgeordie

[zyxwv]

Painting your roof white will reflect a lot of radiant heat.

[Denim]

Post a picture of the house then we can see what you are up against.

 

Otherwise do what a lot of Thais do. Use the upstairs as a storage area / attic and build rooms on the ground floor where it should be cooler.

[zyxwv]

It shouldn't be hard to unscrew the metal sheeting....roll out insulation under it over the battens and / or between beams (with foil-backed insulation for extra reflection of radiant heat) Could be as little as 50mm of insulation but more is going to be a lot better (best quality you can find is worth it). Then screw the sheeting back on. making sure that the screwholes are  (roof and gutter silicone) waterproofed.

screw down partially, then apply silicone so that it squeezes up around base of screw and down around sides of screw's inclines spiral plane. If there are any sharp ridges around screwholes file / grind them off...you can put in a rubber washer for extra safety from water.

[eyecatcher]

Believe it or not, being on stilts 2m high is a fantastic cooling aid but I would get rid of any metal flat roof and form a pitched roof with tiles that are not going absorb and conduct heat like a tin roof.

 

Trees are a great bonus, not only do thry offer shade but they also reduce the effects of smog in the air, which is very noticeable in chiang mai.

I lined my walls recently with a 3inch insulation batt, it wasnt really necessary but the cost was negligable and I was refurbishing anyway.

My house is also a typical thai house on tree legs.

[Denim]

2 minutes ago, eyecatcher said:

 

My house is also a typical thai house on tree legs.

 

Is it triangular shaped then ? ????

[Kron]

Install an extract fan as high up as possible. Certainly in the evenings this draws in the cooler air

[mokwit]

Having done all this, you should do what a lot of the Thais do and install air conditioning.

[eyecatcher]

25 minutes ago, Denim said:

 

Is it triangular shaped then ? ????

Excellent, I am intrigued now how long it will take others to cotton on to your reply

[Artisi]

44 minutes ago, Denim said:

 

Is it triangular shaped then ? ????

only to the Irish ????

[Kwasaki]

1 hour ago, akirasan said:

1) Rebuild the roof - but what materials are the best?

Leave existing roof and construct a high pitched composite metal roof on top.

 

1 hour ago, akirasan said:

2) Insulate the walls - which insulation is best for cooling?

Use thick insulation batts and one of the suitable lining board materials available.

 

1 hour ago, akirasan said:

3) Shade the outside wall with trees

Banana trees in combination of external bamboo roller screens.

[sometimewoodworker]

2 hours ago, akirasan said:

2) Insulate the walls - which insulation is best for cooling? and is there any way to keep mice and rats from making a home in there? 

Do not use polystyrene as they will love it, polyurethane is a good choice.

[eyecatcher]

The key to wall insulation is to keep those animals out. If you can do that, then what you use doesnt matter.

my insulation is foil wrapped as the majority are, but whether its jingjoks or squirrels that can get in, that crinkling foil behind your ears at 4am is a bloody nuisance.

[Enoon]

 

As an immediate solution covering the metal roof with ready made palm-thatch battens will cut down its heat absorption (and radiation into the living space) greatly.

 

 

Very cheap and little time to achieve.

 

Decide if you want more sophistication/cost at your leisure.

 

Or stick with a truly traditional "old" style!

 

 

 

 

[4MyEgo]

I recently insulated our roof space with SCG R-38 insulation batts and also installed two whirly birds and put in those saloon door style louver vents on either side of the front of our house.

 

Now you and others probably won't believe this, but the house feels like it has the air conditioner on all day.

 

We do not use any of the 6 air conditioners that we have, yesterday was 38 and we didn't even have the fans on, although last night I turned one on at the lowest speed but have to turn it off at around 3.00am.

 

Prior to insulating the roof space, we had thermal reflective insulation under the roof tiles, it worked till about 10-12pm, but then we had to turn on air conditioners (2) front of house and back of house.

 

We also recently purchased some shade cloth 2 x 3 metres from DoHome around 500 baht each and have put them up like wide eaves at an angle to shade some west facing walls and the difference is like day and night, i.e. those rooms do not get hot, whereas they were like ovens before.

 

Do yourself a favour, spend, spend, spend, as there is nothing worse than being uncomfortable, air conditioners will only make you dry and sick, trust me on that, we don't like them, but in trial and error, we have reduced our heat inside the house by 10 degree, that is a huge difference, right now, I am cool, not sitting here and sweating like I used too and argue with the Mrs over nothing, now we both bit the kids to shut the doors when they come in....lol

 

The thermal reflective insulation reduces the time the heat takes to penetrate into your ceiling, the insulation reduces the heat from entering your house below the ceiling, whirly birds and vents keep the heat moving out.

 

I have a BIG single level house of about 320m2 and both set me back 120,000 all up, BEST investment I have ever made here in Thailand, if I knew this before I purchased the 6 air conditioners I could have saved some bucks, but like I said, trial and error.

 

Your going to have to insulate and cover the side walls as well as insulate your ceilings, suffice to say, it will also depend on whether you have any ceiling space, I can stand in mine to give you an example.

 

Good luck

[emptypockets]

1 hour ago, 4MyEgo said:

I recently insulated our roof space with SCG R-38 insulation batts and also installed two whirly birds and put in those saloon door style louver vents on either side of the front of our house.

 

Now you and others probably won't believe this, but the house feels like it has the air conditioner on all day.

 

We do not use any of the 6 air conditioners that we have, yesterday was 38 and we didn't even have the fans on, although last night I turned one on at the lowest speed but have to turn it off at around 3.00am.

 

Prior to insulating the roof space, we had thermal reflective insulation under the roof tiles, it worked till about 10-12pm, but then we had to turn on air conditioners (2) front of house and back of house.

 

We also recently purchased some shade cloth 2 x 3 metres from DoHome around 500 baht each and have put them up like wide eaves at an angle to shade some west facing walls and the difference is like day and night, i.e. those rooms do not get hot, whereas they were like ovens before.

 

Do yourself a favour, spend, spend, spend, as there is nothing worse than being uncomfortable, air conditioners will only make you dry and sick, trust me on that, we don't like them, but in trial and error, we have reduced our heat inside the house by 10 degree, that is a huge difference, right now, I am cool, not sitting here and sweating like I used too and argue with the Mrs over nothing, now we both bit the kids to shut the doors when they come in....lol

 

The thermal reflective insulation reduces the time the heat takes to penetrate into your ceiling, the insulation reduces the heat from entering your house below the ceiling, whirly birds and vents keep the heat moving out.

 

I have a BIG single level house of about 320m2 and both set me back 120,000 all up, BEST investment I have ever made here in Thailand, if I knew this before I purchased the 6 air conditioners I could have saved some bucks, but like I said, trial and error.

 

Your going to have to insulate and cover the side walls as well as insulate your ceilings, suffice to say, it will also depend on whether you have any ceiling space, I can stand in mine to give you an example.

 

Good luck

two whirly birds for 120,000? Or is that the total cost for everything you did?

I've seen some solar powered whirly birds in Oz which work even if their is no wind - daytime only obviously!

[4MyEgo]

4 minutes ago, emptypockets said:

two whirly birds for 120,000? Or is that the total cost for everything you did?

I've seen some solar powered whirly birds in Oz which work even if their is no wind - daytime only obviously!

Total cost, whirly birds from memory were 1,500 baht each, the BIG ones and they spin all day long, not noisy at all.

[Ulic]

Lots of ways, and between your plans and what has been suggested you can achieve a lot. The main challenges will be budget and aesthetics. You can paint the roof and walls silver to reflect the heat, but it will not be very attractive. removing the roof adding insulation and venting properly between the insulation and roof surface will be effective but expensive, as will insulating the walls inside the home, but you will retain the house aesthetics. Fast growing trees to provide shade will take time but will also help immensely. Good luck with the project. 

[Lacessit]

6 hours ago, sometimewoodworker said:

Do not use polystyrene as they will love it, polyurethane is a good choice.

Polyurethane is a terrible choice. In any kind of fire, it will break down to form a number of toxic compounds in the smoke, including hydrogen cyanide. Fibreglass batts don't burn.

[Lacessit]

7 hours ago, eyecatcher said:

Believe it or not, being on stilts 2m high is a fantastic cooling aid but I would get rid of any metal flat roof and form a pitched roof with tiles that are not going absorb and conduct heat like a tin roof.

 

Trees are a great bonus, not only do thry offer shade but they also reduce the effects of smog in the air, which is very noticeable in chiang mai.

I lined my walls recently with a 3inch insulation batt, it wasnt really necessary but the cost was negligable and I was refurbishing anyway.

My house is also a typical thai house on tree legs.

Tiles absorb heat more slowly. However, they also shed the heat more slowly. Swings and roundabouts. Although admittedly a tile roof is a lot less noisy than a tin roof when it rains.

The other consideration is mass. Tile roofs are a lot heavier than than tin roofs, so the OP would have to be confident the existing structure could take the extra load.

I agree creating a pitched roof with soffit ventilators and ceiling insulation will give more temperature control.

[sometimewoodworker]

15 minutes ago, Lacessit said:

Polyurethane is a terrible choice. In any kind of fire, it will break down to form a number of toxic compounds in the smoke, including hydrogen cyanide. Fibreglass batts don't burn.

A little research will show that there are fire retardant additives that reduce or eliminate the ability of PU to sustain combustion.

 

The best place to be in a fire is Somewhere else.

 

The fibreglass doesn't burn but the glues and covers do, the loose fibres during installation do wonders for your lungs and skin 

[Lacessit]

1 minute ago, sometimewoodworker said:

A little research will show that there are fire retardant additives that reduce or eliminate the ability of PU to sustain combustion.

 

The best place to be in a fire is Somewhere else.

 

The fibreglass doesn't burn but the glues and covers do, the loose fibres during installation do wonders for your lungs and skin 

The fire retardant additives for polyurethane are usually organo-phosphorus compounds. Note they are fire-retardant. They don't stop liberation of toxic compounds from the polyurethane when the temperature is high enough.

You can't have it both ways. Encapsulated fibreglass means your comment on loose fibres is irrelevant.

"The best place to be in a fire is somewhere else?" You win my award for superficial comment of the week.

I was a research chemist, and had several years experience in polyurethane foam development. Please tell me your qualifications in this field.

[sometimewoodworker]

1 hour ago, Lacessit said:

Please tell me your qualifications in this field.

Someone who has always been somewhere else when there has been any fire involving PU, while you may consider it superficial I consider it prudent.

1 hour ago, Lacessit said:

Encapsulated fibreglass means your comment on loose fibres is irrelevant.

No really as I have never seen fibreglass insulation installed without the rolls often needing to be cut. 

 

All materials will burn "when the temperature is high enough" and it is wise not to be there.

 

[eyecatcher]

Regarding the whirlybird type ventilators, there are two different types, passive and powered.

 

Unless they are powered I really have doubts that a passive wind powered model actually works.

 

The principle is that wind turns the  vanes creating a vacuum effect and sucking out hot air.

 

However, having lived in the North for several years, I can probably count the number of times we have had anything even approaching a breeze, most of which is a pressure breeze prior to a rainstorm which are 9/10 in the evenings.

When was the last time you saw a flag actually flying?

So, Thailand doesnt get windy and the cheap 1500bt vents have no chance of worki g efcectively.

 

Motorise them and yes they very likely will work.

The solar cells obviously create the energy to turn them but typically you dont see them here.

[Lacessit]

9 hours ago, sometimewoodworker said:

Someone who has always been somewhere else when there has been any fire involving PU, while you may consider it superficial I consider it prudent.

No really as I have never seen fibreglass insulation installed without the rolls often needing to be cut. 

 

All materials will burn "when the temperature is high enough" and it is wise not to be there.

 

Interesting. A person is sleeping in a house, and a fire breaks out. If I am following your logic, they are supposed to wake up and decamp immediately. That'll work if they have smoke alarms. And if they are able-bodied.

I saw an installation of fibreglass rolls here once. The installer didn't cut any rolls, simply doubled it over in the roof space.

Noted you do not dispute PU in a fire will generate toxic compounds, including hydrogen cyanide. The same chemical used in gas chambers. Also noted you have nothing to say w.r.to your qualifications.

[superal]

Topic is of interest to me as my lady has just had a new commercial kitchen built to the back of the property , without any input from me , to typical Thai methods . Well the apex roof is foil backed corrugated aluminum with two semi clear full size sections for daylight . The result is that even without cooking the temperature reached 40c in the kitchen when outside it was 37c and all this with two overhead fans and windows / doors .

So having done some asking around I heard of another falang whose solution to the same problem was to build another roof on top of the original to stop the direct hit from the sun and to some extent it worked . I then asked the Thai builder for a quote to do the same double roof but he came up with a proven solution and much cheaper which was to take out  a complete section of the roof each side of the ridge ( about 1.5 mtrs each side ) and then build another roof section 75 cms above with meshed in sides to stop birds and insects .This allows the hot air to escape and also creates a vortex effect especially if there is any outside breeze . The two ceiling fans will then also be effective to expel the hot air as up to now they have only been circulating the hot air and exacerbating the problem .  However the kitchen will never be cooler than the ambient temperature and so I think I may have to introduce a low level air-con unit .

To akirasan I would say that concrete roof tiles are the best bet if you can afford them as they are maintenance free and a long life product , plus no noise from the heavy rains . The steel work support structure for the tiles will not be cheap so an easy fix may be the tin roof modification  but get a good reputable builder .

 

 

[sometimewoodworker]

3 hours ago, superal said:

I then asked the Thai builder for a quote to do the same double roof but he came up with a proven solution and much cheaper which was to take out  a complete section of the roof each side of the ridge ( about 1.5 mtrs each side ) and then build another roof section 75 cms above with meshed in sides to stop birds and insects .This allows the hot air to escape and also creates a vortex effect especially if there is any outside breeze . The two ceiling fans will then also be effective to expel the hot air as up to now they have only been circulating the hot air and exacerbating the problem

That idea is good unless you live in any area where sugar cane or stubble is burned.

if you live in that kind of area you will have black dust or flakes entering for part of the year and making the cook really unhappy with the design. 

 

We considered it and SWMBO vetoed the idea.

 

On some of the islands I know it is in place and works well. I even have a bluescope design drawing of the method that was used.

[Ahab]

Try the metal roof with radiant barrier sheathing attached (don't buy the cheap stuff ask for the good type 30 baht/m2 vs. 60 baht/m2). We went with a white Bluescope roof and you will feel almost no heat coming through it during the hottest part of the day. We also installed solar powered attic fans to suck the hot air out of the attic and bring in cooler air from under the eaves. Large overhangs keep most of the house shaded during the day.

 

Getting rid of the corrugated tin roof will yield the greatest results, and I highly recommend the Bluescope metal roof with the high quality radiant barrier sheathing attached at the factory.

[Ahab]

14 hours ago, eyecatcher said:

Regarding the whirlybird type ventilators, there are two different types, passive and powered.

 

Unless they are powered I really have doubts that a passive wind powered model actually works.

 

The principle is that wind turns the  vanes creating a vacuum effect and sucking out hot air.

 

However, having lived in the North for several years, I can probably count the number of times we have had anything even approaching a breeze, most of which is a pressure breeze prior to a rainstorm which are 9/10 in the evenings.

When was the last time you saw a flag actually flying?

So, Thailand doesnt get windy and the cheap 1500bt vents have no chance of worki g efcectively.

 

Motorise them and yes they very likely will work.

The solar cells obviously create the energy to turn them but typically you dont see them here.

Heat rises from the hot attic, the passive whirlybirds do not need wind to operate.