Approprate venting for Colorbond Roof

anna123456 · Mar 31, 2023 5:39 pm

Hi there,
My newly built house has been terribly hot this very mild Perth summer, despite having Anticon and ceiling insulation. The house is tiled in all rooms and white external aluminium shutters on all windows stay down all day long until we get home after 6pm, so I am very surprised that so much heat is being retained.
My partner suspects the roof does not have appropriate venting - it is a huge roofspace, and has one ridge vent and two eave vents. The builder refuses to discuss the issue with me, stating they provide all clients with one ridge vent and two eave vents.
Surely builders should calculate roof space and provide appropriate ventilation? I have asked multiple times if this is calculated but have not received an answer. Am just about to talk to the Building Commission of WA but would appreciate if anyone has any insights?
Thank you, Anna

StructuralBIMGuy · Mar 31, 2023 6:06 pm

hey anna123456 Welcome to the forum

anna123456

Surely builders should calculate roof space and provide appropriate ventilation? I have asked multiple times if this is calculated but have not received an answer.

If anyone has airflow calcs then they should be in the certified energy report?

anna123456

Am just about to talk to the Building Commission of WA but would appreciate if anyone has any insights?
Thank you, Anna

Without that data you are wasting your time at the BC
BTW Proper airflow simulations cost several $000s.. bit too late now...but may help others, of course, before they sign up

Althom · Apr 02, 2023 12:10 pm

anna123456

Hi there,
My newly built house has been terribly hot this very mild Perth summer, despite having Anticon and ceiling insulation. The house is tiled in all rooms and white external aluminium shutters on all windows stay down all day long until we get home after 6pm, so I am very surprised that so much heat is being retained.
My partner suspects the roof does not have appropriate venting - it is a huge roofspace, and has one ridge vent and two eave vents. The builder refuses to discuss the issue with me, stating they provide all clients with one ridge vent and two eave vents.
Surely builders should calculate roof space and provide appropriate ventilation? I have asked multiple times if this is calculated but have not received an answer. Am just about to talk to the Building Commission of WA but would appreciate if anyone has any insights?
Thank you, Anna

If it's you typical WA builder job there was no calculation done in respect of ventilation.
The roofing contractors just do what they did on the last job.
Unless you specify the number of vents etc you're just going to get what they give you.
Our 195m2 house has 3 ridge vents and 6 eave vents.
We specified the 3 ridge vents but left the eave vent number up to the builder who insisted we didn't need any.
I retrofitted the eave vents after talking to the people who manufacture the ridge vents.
Building Commission won't help, total waste of time.
Discuss with your builder but don't expect them to budge.
Maybe time to just get hold of a roofer and get them to install more ridge vents and do more eave vents yourself

anna123456 · Apr 02, 2023 1:28 pm

StructuralBIMGuy

hey anna123456 Welcome to the forum

anna123456

Surely builders should calculate roof space and provide appropriate ventilation? I have asked multiple times if this is calculated but have not received an answer.

If anyone has airflow calcs then they should be in the certified energy report?

anna123456

Am just about to talk to the Building Commission of WA but would appreciate if anyone has any insights?
Thank you, Anna

Without that data you are wasting your time at the BC
BTW Proper airflow simulations cost several $000s.. bit too late now...but may help others, of course, before they sign up

hi StructuralBIMguy, thanks for your comments, I have tried reading the energy report but have found it a bit hard to decipher, if the calculations are there, they are definitely not clearly labelled as "roof ventilation"

I will persevere. Kind regards, Anna

anna123456 · Apr 02, 2023 1:33 pm

Althom

anna123456

Hi there,
My newly built house has been terribly hot this very mild Perth summer, despite having Anticon and ceiling insulation. The house is tiled in all rooms and white external aluminium shutters on all windows stay down all day long until we get home after 6pm, so I am very surprised that so much heat is being retained.
My partner suspects the roof does not have appropriate venting - it is a huge roofspace, and has one ridge vent and two eave vents. The builder refuses to discuss the issue with me, stating they provide all clients with one ridge vent and two eave vents.
Surely builders should calculate roof space and provide appropriate ventilation? I have asked multiple times if this is calculated but have not received an answer. Am just about to talk to the Building Commission of WA but would appreciate if anyone has any insights?
Thank you, Anna

If it's you typical WA builder job there was no calculation done in respect of ventilation.
The roofing contractors just do what they did on the last job.
Unless you specify the number of vents etc you're just going to get what they give you.
Our 195m2 house has 3 ridge vents and 6 eave vents.
We specified the 3 ridge vents but left the eave vent number up to the builder who insisted we didn't need any.
I retrofitted the eave vents after talking to the people who manufacture the ridge vents.
Building Commission won't help, total waste of time.
Discuss with your builder but don't expect them to budge.
Maybe time to just get hold of a roofer and get them to install more ridge vents and do more eave vents yourself

Hi Althom, thanks so much for your comments. Yes, typical WA project builder!! I think we will just end up getting more vents done ourselves too. Cheers, Anna

Pulse · Apr 02, 2023 2:24 pm

The roof is a small part of the big picture, orientation, shading of windows etc has a much greater effect. A thermal camera and a review of your plans would be more helpful.

anna123456 · Apr 02, 2023 4:07 pm

Pulse

The roof is a small part of the big picture, orientation, shading of windows etc has a much greater effect. A thermal camera and a review of your plans would be more helpful.

Thank you Pulse, I thought we did the right things; external shutters on all windows down all day, west side of the house nearly completely in the shadow of the large two storey next door. Will definitely think about plants for shading and thermal camera is excellent idea, didn't think of that, thank you. Kind regards, Anna