How to identify load bearing wall

[Panda]

Hi All,
Thanks for the responses. I was not intending on doing any work without an engineer etc (and I certainly wouldn't go and knock out a wall based on a forum comment).

I was more interested in just being able to identify if it was load bearing. If its not I would consider it something that I could potentially consider if it is I would more than likely consider it not an option at all. Either way it needs to add value beyond the cost.


Ill also check out the other links.

Thank you all.

 

[A Jeremy]

While trusses are generally designed to bear load only on external walls, they can also be designed to utilise internal load bearing walls. This comes into play when engineering the trusses and the manufacturer may be able to use smaller members - profile(timber) or gauge(steel) - in the construction of the trusses if internal walls can bear load, decreasing the spanning requirements of the truss.

 

[dev2ret]

So without the availability of existing plans how is an engineer actually going to determine if a wall is load bearing. Would they not do a visual inspection. I know I would.

 

[dex]

Dev, yes an inspection is required but you don't need an engineer. Any builder or carpenter should be easily able to determine if a particular wall is load bearing or not by sticking their head into the roof space and seeing if the wall is supporting the roof.

 

[A Jeremy]

Intermediary walls that run under trusses, but don't bear load, are supposed to be a minimum of 10mm below the underside of truss however if this requirement weren't met, I can't see a certifier telling the builder to lift the trusses 10mm or somehow reduce the height of a block wall by that much.

It's the difference between certainly and likelihood.

 

[Scott_Snap]

Just a note on trusses--- Wall debate aside

Picking Load Bearing walls can be next to impossible. I have made and engineered trusses for 20 years and consult to the industry.

There is a function to design the trusses supporting off all or some of the internal walls with or without an internal member in the truss directly over the wall or Inter-panel support point. This is the main method in NZ and other places where they build all walls the same height so I am told. I haven't seen it first hand but that was the reason for the function according to Mitek (Gang-Nail) but can happen here in Australia. If a designer specifies a low max deflection limit like in Adjoining units and fire walls it is quite common. So unless its parallel assume it is supporting.

Without the manufactures computations you would need Mitek or one of the nail plate suppliers to certify it for you before its assumed not to be. To tell which brand of plate it will be embossed in it or there is paint on the plate.
Blue Mitek Red Pryda Green Muti-Nail. An engineer can attempt too, but without the plate capacities from the manufacturer I fail to see how they can and the nail plate suppliers don't give away there IP lightly.

The biter is the profile of the truss probably will not change! it will be the timber grade that alters and the grade is what determines the plates size and thickness. You can not go by eye.


Cheers