Building A New House

[CharlesHolzhauer]

I am in the process of building a new 81-square-meter, one-bedroom house elevated on 16 concrete columns, each measuring 2.20 meters in height. The drilling for 7-meter-deep concrete piles has been completed, with rebar inserted and CPAC delivering and pouring the concrete using a mixer truck. A backhoe has already excavated around the piles to prepare for the foundation setup.

 

For the roof, I have opted for a single flat-sloped design, using hot-dipped galvanized single-skin sheets with thick insulation attached, manufactured by BlueScope.

 

I would appreciate insights from those with experience using this roofing material. Specifically, I am curious whether the insulation remains securely attached over time or if detachment is a common issue. If so, would it be advisable to install a wire mesh support (e.g., chicken wire fencing) beneath the roofing before installation to prevent insulation from coming loose?

 

The house walls will be built entirely from aerated concrete blocks, and the floor will be reinforced concrete. The ceiling will be constructed using 1-inch thick Shera panels, supported by metal beams.

 

The attic, which will be internally accessible, will have a height of approximately 1.80 meters at the front and 1.50 meters at the back. Like the rest of the house, it will be enclosed with aerated concrete blocks and will feature large windows on all sides, which will remain open for most of the year to facilitate airflow.

 

Given my current insulation plan, do you think these measures are sufficient to ensure a well-insulated and energy-efficient home? Or should I consider additional insulation strategies?

[GreasyFingers]

With regards to the insulation foam on the underside of the metal sheeting, you could have some problems with discolouring and breakdown after a few years if you use a cheap one. We have just built a garage and used the insulated sheeting that had a lining under the insulation. Probably more for cosmetic reasons but looks a lot better that the exposed insulation.

 

Large windows on all sides will mean that it is not energy efficient even with being open.

[sometimewoodworker]

16 hours ago, GreasyFingers said:

With regards to the insulation foam on the underside of the metal sheeting, you could have some problems with discolouring and breakdown after a few years if you use a cheap one. We have just built a garage and used the insulated sheeting that had a lining under the insulation. Probably more for cosmetic reasons but looks a lot better that the exposed insulation.

 

Large windows on all sides will mean that it is not energy efficient even with being open.

With regards to the insulation under the roof, we have use 3 versions,

 

the first is sprayed on PU, in the house it has yellowed but there is no breakdown it is expensive.

 

On the outside kitchen we used cheap steel with a stuck on foam with an aluminium foil on the underside, this rusted through in spots and the foam came off after a couple of years.

 

the last roof over the outside kitchen is a sandwich of steel, foam, and steel. So far it has only shown signs of quite rapid fading of the top surface but the sandwich shows no sines of breaking down, though it’s only been about 2 years.

 

With large windows, they can be reasonably energy efficient, the majority of ours are, but that requires them to be shaded from the sun. We have a minimum 2.5 metres overhang of the roof so some of them  only get early morning and late afternoon sun, the others no direct sun. However they are also double glazed with low-E glass so are also sound attenuating, the give about a 24db drop.

[KhunLA]

Used the thickest insulated BlueScope (3 thickness available ?) on present house, and 3 yrs on, and staying firmly on.

 

Insulation wise, works great, with added rolled out insulation on all the ceilings.   Also used the aerated block, K block or whatever version name goes by (not cinder), and the house stays very cool.  South & West walls are almost entirely shaded.   Sun is off the East facing glass doors by 0800 hrs, due to extended roof over the veranda, and full indoor curtain are used to block the sunlight.  Little ambient comes through the glass itself.

 

Have a 13k BTU in the bedroom (~25m²), and a 24k BTU in the main house area (~80m²).   Open door between those rooms, and house stays very cool.   ACs don't struggle at all.

 

Laundry & storage room run the length of South wall, as buffer to main house.  Carport on West side of house.

 

[AlexRRR]

Windows on all sides isn't a great idea since most of the heat would come in through the glass if unless you shade them.