Concrete Brick House too hot in summer

Hi guys,

Some of you know or remember that we just bought an old house (1950s) and moved in 2 weeks ago.

We are very happy in the house, however, this week we had a day with 42 degrees warm and we were surprised the house got very hot inside very quickly.

I checked the ceiling and house has insulation but it seems it is very old and thin. I'm wondering whether or not fitting a new insulation will make the house much less warmer than it is currently now?

I'm looking to see if it is worth the investment in new insulation not only temperature wise aut also when we decide to put aircon at home and not getting higher bills due to the aircon working too hard to keep the temperature low.

House is a concrete brick on timber floor and timber roof on top with old concrete tiles.

 

Install a roof ventilator as a first step and see how that goes before replacing the insulation.

Get a couple of quotes to replace the insulation or to patch where it's missing (which may also be part of the problem. Guys who came out to inspect mine said that the insulation was fine (Kevin '07) but a whirlybird would cost a few $ hundred.

 

As well as looking at ceiling insulation, tryto stop heat entering the house through the windows and walls. For example, with external blinds so sun doesn’t hit window glass.

Also, consider ways to screen the external walls from getting sun on them. For example, planting a vine or deciduous tree on the western side, using shading pergolas etc.

Does the house have eaves - and how wide are they?

 

Well, thing is that lounge and master bedroom don't receive afternoon sun. Besides, windows have those old blinds awnings I think it is called? So that is why it surprised me to feel both rooms so hot inside, master bedroom faces South with second bedroom next to it receiving afternoon sun. Lounge also faces South and East.

I will look into those roof ventilators, any recommendation for the type to choose or look into?

 

In 42 degree heat, every house will be warm inside. Did you close up all the windows and doors and cover them all with thick curtains or blinds? Any rooms facing south will get the full blasts of Summer sun.

 

OK. Is sun hitting the walls or windows on the eastern or northern sides?

 

Yes, sun is hitting mostly the wall on the side where 2 bedrooms a bathroom and laundry are. Please see the picture I just attached:

The front has 2 windows one for each bedroom. Master bedroom is the one in the corner closest to the entrance with 2 windows. The other window next to the carpark is the lounge.

On the North side we have part of the lounge, kitchen and part of the laundry.

Windows are closed all the time except for next day when temperature dropped to cool the house.

Another thing worth mentioning is that the house is also very cold when temperature drops, we even needed to use quilts the week we moved at the beginning of November.

Thanks for the inputs guys.

 

You can buy some great modern versions of the whirlybird.
Solar powered fan vents, some will have a thermostat so they don't start working until 30 deg (that way they don't suck all the warm out in winter).

 

Also solar powered ones are much more efficient at moving air than the standard whirlybirds. I think ATA did an article on this in their Renew publication.

 

Hey @iwantahouse there are quite a few things you can do.

Definately put in a whirlybird but you also kinda need to stop the sun from hitting the concrete and get some internal airflow happening.

Here's a guide that I found very useful for Darwin. Obviously you won't be able to do everything in here but hopefully there might be a few ideas that help.

Sustainable Tropical Design - COOLmob

 

Oh... Just saw your photo...

Your roof is very dark. It'd be just soaking up all the heat the sun can throw at it.

I'd be getting that painted white pronto.

 

Speaking of dark roofs, we are currently about to undertake a new house build, and have been trawling the Display Villages for ideas for colours and finishes for the last year (all done now, thankfully).
We have decided on a corrugated tin roof in colorbond colour "surfmist" which is very light.
This has made me more acutely aware of what colour people select for their roof.
What I have noticed is the overwhelming majority of people go for charcoal grey, and usually tiles of some sort.
One thing that might help make the house in this thread cooler is to get more tree shade around the house.

 

I agree it is dark but it might not need to be painted white. White tiles look awful.

Options
1. paint roof with heat reflective paint
2. put solar panels on the roof. The added bonus of solar but the panels actually shade the roof tiles and help keep the roof cool
3. reroof with colorbond in a lighter colour. THis is probably the most expensive so I would go option 2 as my preferred option.

Other options to help cool an existing house
1. plant trees and shrubs on north and western side to help reduce sunlight falling on the house. Deciduous ones allow the light to still come in Winter otherwise you'll end up with a freezing house (sounds like you already have that issue)
2. insulate the blockwork. I'm not overly familiar with this style of blockwork but I have used expanding foam insulation between bricks in Perth which might also work
3. check the windows - double glazing or tinting the windows may help prevent heat gain/loss
4. read as much as you can of YourHome | Australia's guide to designing, building and living in environmentally sustainable homes. and see what other ideas there are

 

I seem to recall reading a report recently that indicated that the effect of dark roofs with reflective sarking from memory is not as bad as you might think as a contributor to a house heating up. But the amount and type of sarking might be crucial. (Then again it might have been a rubbish study!)

Light coloured roofs are still better though.

Read what Dr Chris Reardon has to say here (5-year old article) Cool roofs V dark roofs – special report

Also, Colourbond colours have become more reflective in recent years with advances in paint technology.

Colours that we’re previously rated as a medium are now rated light (more reflective).

 

Yes, I think that with todays standards of roof insulation, the colour of the roof may be a minimal impact, but was an interesting observation.