Steel frames - Coral homes

We are building Low Set - 1 Level only. Due to land bring closer to main road, we are adding acoustics as additional as well.


thanks will check the Instagram as well

That person's story on Instagram is pretty bad. It's not the Coral Homes I know. I have heard of similar problems with noisy floors recently, and in that persons case I'm wondering if it comes down to how they've attached the floor (yellow tongue boards etc) to the frame. But it does sound like a metallic sound, almost clicking. Not good.

We built with Coral in 2012/2013 and got their first steel frame built in NSW. The frame is actually a product from Stoddart and a few builders use the same now. Our place was a Noosa design, single level house.

Back to the op questions - as a home owner the steel frame layout is the same to work with in some aspects. It has the same basic components as a timber frame (studs, noggins etc) so screwing something to the wall is the same process as timber. My stud finder had no trouble picking the frame up through the plaster. I also got a couple of rare earth strong magnets and they'd stick in the right places too.

I can tell you a few carpenters I saw onsite during the build swore off the steel frame. They're obviously used to timber, and soft timber too when the frames are new. So screwing anything in and cutting holes through is trivial, and it's also an easier material to modify on site. The steel frames are tougher, it's a pro and a con. The frames have pre-punched holes for cabling and plumbing to run through, which helps trades a lot - you wouldn't want to be drilling a lot of holes through a steel frame, it'll take a while.

I spoke to the guys putting up the Gyprock linings on our place and the steel didn't bother them any.


We modified a few smaller elements during our build, including adding a sliding cavity door where there wasn't one on the plan and the frame was modified as required. They can be cut. The frames are an assembled component and can be unscrewed and rejoined. Timber is easier to work with like that, no doubt.

I think there's a bit of truth and fud out there on steel. Yes, they do "ping" but in our experience it takes a pretty quick temperature change outside for that to happen. It was the roof trusses that'd ping on our place - there is a little bit of movement in some components. I'd say one issue with steel frames that doesn't get enough attention is the thermal transfer. If you've got a Colorbond steel roof screwed down to steel battons screwed onto steel trusses the outside temperature transfers through that combination. That's the setup we had and I wouldn't say our walls were warm but the few times I was in the roof space on a hot day, the steel trusses were hot to touch and that's all going somewhere. I had two whirlybirds on that roof and vents in the eaves too.

For that reason I like the hybrid frames that builders like Clarendon are going with, where it's a steel house frame with timber roof trusses on top. I think the primary reason they do that is for supporting roof tiles, but I like the thermal barrier the timber provides too.

We didn't get any cracks in walls and the Coral staff who did the 6 month visit after handover to fix other things said that was interesting to see, because they regularly get cracking with timber framed houses as the timber dries and hardens. I don't know what to make of the concept that steel is rigid so the Gyprock will crack as the "house moves". To my thinking a rigid steel frame is a good thing and the entire point of using steel - these houses are meant to stay where they're built, yes? So any moving in that concept might be the slab moving (settling?) on the ground. That sounds like a different problem to me.

Would I build with steel again? Absolutely. We're currently in the council D.A process now for a steel framed house with Mojo. I'm interested to see if if it's same steel frame as their parent McDonald Jones uses - surely it will be. I do know it's a hybrid with the timber trusses on top and I'm happy about that. We'll be using a Hebel Powerfloor (concrete) 1st floor so hopefully we'll completely avoid any floor noise/movement issues like that reported on Instagram, but it'll still be yellow tongue under the wet areas... so, I'll be keeping an eye on that.

Agree, and it's a good thing they're mandatory under a steel roof. At least in NSW that I know of.

But I wonder how efficient the roof blankets are, or how much efficiency is lost, if the steel roofing is screwed through them? I understand the primary point of the AntiCon blanket is to stop condensation forming on the inside of metal roofing.

I am horrified at the noisy floors that were posted on instgram by sapphire5727. I would like to know if this was rectified in the end, and I would also like to know if the owner raised the ongoing disputes with Fair Trading NSW, and did they help?


Thermal breaks in steel framed homes

I am building in QLD, and I may be opting to go with a steel frame. With regard to thermal breaks, I did some research into the NCC 2019, which was amended to include thermal break requirements. Whilst the amendments to the code have been released, I read somewhere that adherence to the latest amendments are not mandatory until sometime in middle of 2020.

With this in mind, I figure that if I was to commence building right now, I would need to explicitly ask the builder to ensure that thermal break will be installed, and have this explicitly written as an inclusion in the building contract. I took most of the wording from the NCC 2019, and I would intend to ask for the following wording to be included in the building contract.

By the way, anyone can register an account at the ABCB website, and from there the NCC 2019 is free to download.

Thermal break requirements (for steel frame home only):

Requirement 1: The roof must have a thermal break, consisting of a material with an R-Value of greater than or equal to 0.2, installed between the metal sheet roofing and its supporting metal purlins, metal rafters, or metal battens.

Note 1: A thermal break may be provided by materials such as timber, expanded polystyrene strips or plywood. The material used as a thermal break must separate the metal purlins or metal battens from the metal deck roofing and achieve the specified R-Value.

Note 2: The client insists that compressed bulk insulation (alone) is not an acceptable thermal break.

Note 3: The purpose of the thermal break is to ensure that the thermal performance of this form of roof construction is comparable to that of a similar roof with timber purlins or timber battens.

Requirement 2: Lightweight external cladding walls, such as weatherboards, fibre-cement or metal sheeting fixed to a metal frame, must have a thermal break consisting of a material with an R-Value greater than or equal to 0.2.

Note 1: Because of the high thermal conductance of metal, a thermal break is needed when a metal framing member directly connects the external cladding to the internal lining or the internal environment. The purpose of the thermal break is to ensure that the thermal performance of the metal framed wall is comparable to that of a similarly clad timber-framed wall.

Note 2: A thermal break may be provided by materials such as timber battens, plastic strips or polystyrene insulation sheeting. The material used as a thermal break must separate the metal frame from the cladding and achieve the specified R-Value.

Note 3: Expanded polystyrene strips greater than or equal to 12 mm thickness and timber greater than or equal to 20 mm thickness are deemed to achieve an R-Value greater than or equal to 0.2.

Note 4: The thermal break must be installed at all points of contact between the external cladding and the metal frame.


I think this should take care of thermal transfer via the roof, and via any external cladding walls.

Since my chosen builder and design has a combination of brick veneer, and cladding, I guess the only other vulnerable point in terms of unwanted thermal heat transfer from the brick veneer wall (when the bricks get hot in summer under direct sunlight) into the steel frame, via the steel brick ties. Note, the brick ties connect the brick wall to the steel frame to give the brick wall more structural integrity. Bearing in mind, there is a 40mm gap between the brick wall and the steel frame, but brick ties are made from steel, so they would be highly conductive of heat transfer.

I would appreciate any opinions and feedback.

Mrs, out of curiosity, have you compared the sound with other steel framed homes? I mean, has anyone on this forum built with a steel frame in a 2-story home that can provide their opinion about this? If so, what did they say about the noise in their home?

Yes the sound is horrible, I agree. Irrespective of whether it was built using a timber or steel frame, it shouldn't make that sound.

The floor joists make up part of the overall frame. So, if the frame is timber then the joists will be timber, and if the frame is steel, then the joists will be steel. I was wondering if anyone else has experienced this kind of noise in a 2-story steel framed home.

Thattime, thanks for sharing your findings and experience about building with a steel framed home. Can you clarify, was this a single story or 2-story home?