# Forum Home Renovation Structural Renovation  Trussed roof, gable end, is it a load bearing wall?

## manofaus

Just working out the floor design and wondering if I need to use a joist or bearer that is suitable for a load bearing wall if the roof is made of trusses and the wall is the gable end.

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## OBBob

I would think so but I may be visualising your layout incorrectly. There would either be rafters or small trusses resting on that wall the way I picture it.

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## OBBob

Scrap that... I have hip roofs on my mind! You said gable.

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## METRIX

If your roof is trusses no walls internally are load bearing, only the external walls are.

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## manofaus

So a gable wall is load bearing...? Even though the truss sits on the walls perpendicular to the gable?

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## jimfish

Only the walls the trusses sit on are loadbearing.

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## METRIX

A gable wall will be load bearing if there is no truss is used at this point, this is due to traditional framing methods being used for end of the gables, but saying that, you could use a truss at that point and have the wall open, but this would need to be engineered to suit the situation. 
This part of the building will be subject to lateral forces, so it needs to be built to withstand these forces.

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## manofaus

ah yes. Thanks metrix and others

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## r3nov8or

IME the 'first' truss is placed in line with the inside of the top plate of the gable-end wall (eg just 90mm from the actual outside of the wall framing), and then gable end studs are added to complete the wall, possibly under outriggers etc. I'd build it to load bearing standards just coz, and as Metrix says it needs to be braced adequately, as it doesn't have the inherent bracing of a hip roof design

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## r3nov8or

That is....

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## manofaus

Yes I see. Its not a matter of building the wall to the correct spec but rather the sub floor construction. That pic is great. Thanks

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## r3nov8or

Yeah, understand. In terms of load bearing subfloor, also carefully consider the placement of windows and doors and ensure you have adequate support to the ground.

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## jimfish

On a gable walled job we just double the joists under the end wall. The lateral forces are generally controlled with the gable wall being fixed to the trusses which are braced to prevent any movement.then gable studs are installed and fixed to the truss. There is no roof load on the gable end walls.

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## manofaus

double joist on platform floor still?

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## OBBob

> double joist on platform floor still?

  Yes.

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## manofaus

didn't think it was necessary on a platform floor when the wall is not load bearing.

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## OBBob

> didn't think it was necessary on a platform floor when the wall is not load bearing.

  Wasn't it determined above that it's likely to be loadbearing? If it's not loadbearing then sure, no double joist. I don't know your project but for the cost of an extra joist I'd just be throwing it in.

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