Seeing a lot more flat roofs

[chrisandsu]

Been looking at different house designs the last few weeks as I will be building a new house in the not to distant future. I have come across these roofs (see picture ) is there many Benifits to this or is it just cheap ??

[chrisandsu]

Picture

[trogers]

Part and parcel of using precast concrete elements for construction. Less labor intensive.

[chrisandsu]

Would there be any benefit in heat reflection with the materials used ?

[trogers]

Would there be any benefit in heat reflection with the materials used ?

Not unless you cover the roof with foil...

[Crossy]

It's difficult to see from the photo but if that's a fly-roof then it will help significantly in reducing heat-gain.

http://inexpensivehomebuilding.blogspot.com/2007/04/what-is-flying-roof-how-to-make-flying.html

Similar effect to the high pitched roofs and ventilation used in some traditional Thai homes without the need for a complex structure (so it's cheap to build).

[williamgeorgeallen]

flat roofs are generally used to get another floor in without going over height restrictions. not sure if this is true in thailand. flat roofs do a great job in delaying the incoming heat from the sun. reduce the roof cavity reduce this benefit.

[maderaroja]

The flat roof is less expensive to construct. Most of the flat roofs that I see are "attached" to the main structure without much insulation. Some have only reflective foil under the roof. To be really well insulated from the heat, there should be some foam or glas-wool under the foil. The best use of the flat roof occurs when there is an air space between the actual roof and the "umbrella" roof to allow for air flow cooling.

[Ulic]

Just make sure the roof drains, ie not flat-flat where water pools.

[buythisdashcam]

I always find standard house roof so stupid and wonder why people still build them. Flat root is a chance to make your roof useful !

[Eric Loh]

What happen to the old fashion pitch roof. Less problem of leaking with pitch roof than flat. More airy and have a feeling of space.

[jesimps]

A lot of people think they're in the Med and picture themselves spending loads of time on their roof bbq-ing, sunbathing and supping chota pegs. Unfortunately they find that for 11 months of the year it's too hot and humid.

Give me a pitched roof every time in Thailand.

[bazza40]

Pitch roofs are designed to shed snow, which as far as I know is not a problem in Thailand. Flat roofs are cheaper to build.

There does need to be enough cavity space ( preferably ventilated ) otherwise the air conditioning bills can be eye-watering.

[jacksam]

Most answers incorrect. The cheapest roof is done with pre fab trusses. That's why about 90% single and double story are done this way warmer climates where snow is not an issue. Problem in los is because they exclude people like myself working here, their domestic construction is in dark ages. The skillion roof is good for tropical climates where airflow is necessary. Also can look great with different roof sections pitched at different directions.

Edited January 25, 2016 by jacksam

[MRH1959]

Roofing is a personal choice, so go with what you want to see within your budget.

Be sure you use a qualified builder and not a little al handy man and insist on quality products, especially with cement.

Beware of the following:

Foundation ground that has not been 'set hard'.

Steel joints that aren't primed.

Cracking due to ???

Non squared framework, especially around doors and Windows.

Shoddy electrical work.

Contractors not following through with their work.

You didn't state what area you are building in, though build with your eyes open.

Edited January 25, 2016 by MRH1959

[Eric Loh]

Certainly agree with Jacksam on the roof truss bit. Much cheaper than rafters which is always over over built and easier to install. Better in terms of keeping rain away than flat roof. Not many roof truss fabricators here in LOS. Know of one who fabricates timber roof truss here. Has little success in selling the truss concept.

[jacky54]

Having lived in 2 places with a flat roof I would say never again, both leaked

[jesimps]

Pitch roofs are designed to shed snow, which as far as I know is not a problem in Thailand. Flat roofs are cheaper to build.

There does need to be enough cavity space ( preferably ventilated ) otherwise the air conditioning bills can be eye-watering.

My pitch roof provides me with a huge loft, which gives me loads of space for my junk and allows me easy access to my electrical cables and connections.

If it wasn't for the forest of steel, I'd put a lodger or two up there!

Edited January 25, 2016 by jesimps

[jacksam]

Having lived in 2 places with a flat roof I would say never again, both leaked

They leaked because not installed by someone that knows what to do. Also it is not a flat roof it's a skillion roof. With continuous roofing material they offer the BEST waterproofing.

[jacksam]

Pitch roofs are designed to shed snow, which as far as I know is not a problem in Thailand. Flat roofs are cheaper to build.

There does need to be enough cavity space ( preferably ventilated ) otherwise the air conditioning bills can be eye-watering.

My pitch roof provides me with a huge loft, which gives me loads of space for my junk and allows me easy access to my electrical cables and connections.

If it wasn't for the forest of steel, I'd put a lodger or two up there!

Are you for real. You would cook them. Also whatever pitched roof you used would require much larger floor joists for upper level. Also if a normal pitched roof what under purlins etc. Roof space even on large home is very small. Also you using stairs or ladder. Dream on

[AlQaholic]

Looks like they are partly fly roof and part just tilted flat roof or flat roof. It is generally cheaper to build a flat roof and it has become somewhat of a fashion to build flat roofs world wide the last couple of years.

Personally I think it looks cheap and is a fad that will go away sometime in the future. I think the traditional pitched tiled roof is a better long term solution even if it costs a bit more. They built roofs like that traditionally for a reason.

[crazykopite]

They are not flat in that they have a slight incline to allow the rain to run off they are cheaper to erect than a fully pitched roof and only require guttering where the water runs off so all in all more cost effective. Like any roof it is important to insulate to either keep heat in or out depending on what country you live in. I find them more attractive /contemporary than the normal bog standard pitched roof and with clever design you can use them as a storage area just like pitched roofs !

[bark]

Most answers incorrect. The cheapest roof is done with pre fab trusses. That's why about 90% single and double story are done this way warmer climates where snow is not an issue. Problem in los is because they exclude people like myself working here, their domestic construction is in dark ages. The skillion roof is good for tropical climates where airflow is necessary. Also can look great with different roof sections pitched at different directions.

Your answer is Wrong. Wood is more expensive then cement in Thailand. And like your Pre-Fab wood Trusses; they make pre-fab cement for roofs. And if you want to work for 400 baht a day. I will give you a work permit; and you can work for my construction company.

You also cannot weigh more then 60 kg ! Bamboo ladders.

[thailand49]

I'm not expert but now do the majority of the work myself. When it comes to roofs, what I found out is the old style roof like A-frame usually a good house being build uses that heavy looking type slabs, I know housing using this material the framing must be stronger to take the weigh. These types of roof material (not some of these newer style material) I read due to the heat the framing expand and retracts so after a while you will have leaks? read this was a given no matter how much you pay for your house. If you have the money when your house is being built it is advise to have the undersize spray with insulation foam? this prevents less expansion and leaks? If you drive around neighborhoods you will notice many old homes with cement patching at the top of the roof. That is what I have.. gone a number of times to the top and do patching.

My opinion now is from what I see being build today is the sland roof there aren't any joints or curves and when it rains it just rolls off.. material is cheaper from looks of it.

[chrisandsu]

Sorry about the picture guys I didn't realise it had rotated . From what I could see from these buildings there is a slight gap from the steel frame to the slanted roof (sorry I said flat but it does have a slight pitch to it ) from what I could see it looks quite effective and a bit more modern and obviously if it's cost effective it might well be worth consideration as it won't be my primary house .

[chrisandsu]

Roofing is a personal choice, so go with what you want to see within your budget.

Be sure you use a qualified builder and not a little al handy man and insist on quality products, especially with cement.

Beware of the following:

Foundation ground that has not been 'set hard'.

Steel joints that aren't primed.

Cracking due to ???

Non squared framework, especially around doors and Windows.

Shoddy electrical work.

Contractors not following through with their work.

You didn't state what area you are building in, though build with your eyes open.

I will be building in Rayong the ground seems very sturdy , so I was wondering if I even need footings especially considering I may put a roof like this one on . Do you think it's possible to build a two storey house for under 2 million baht ? I already own the land ( my wife does ) so that's not a cost to consider . Thanks guys

[Fookhaht]

While we're on roofing materials,  I just looked at two building projects (one at a resort, and the other at a pre-built wood-style home) where they used the below type of roofing.  Frankly, it looks like the cheapest possible roof (very thin metal), and running bolts through the upper surface in order to fasten it to the trusses/beams, scares me to death.   I always thought that the cardinal rule of roofing (come from a roofer's family) was NEVER to drill/screw anything through the roofing material from the upper side.  All I can see are these bolts rusting out in future years with massive leakage problems.

Any thoughts on the thin roofing material and running bolts from the upper side into the roof surface (see attached photo)?  

Edited June 8, 2017 by Fookhaht

[Senechal]

Drainage is the principle issue here. Make sure your flat roof has some slope, however minimal.