so-very-very-tired

so-very-very-tired t1_je18n3h wrote

It's not about the weight of an individual...it's what the truss system is rated for in terms of live loads.

They're usually not rated for live loads above/beyond storing your xmas decorations and maybe some boxes of old clothes and the like.

A residential floor it typically rated for 40lb live load. I believe (but don't quote me) roof truss floors are only required to be rated for 20lb live load if only used as attic storage space. And builders tend to use roof trusses for being cheaper to build/install and rarely over-build.

Granted, you can certainly get trusses that are rated much higher, and perhaps that was done here.

For example, there are things called 'attic trusses' which are designed to usually handle 30lb live loads on the floor. The other main advantage is that they are designe to leave a larger open space in the middle (vs your standard roof trusses which use all of the diagonal members as in the OPs photo). These are great when used but they're rarely used by default simple due to them costing a lot more.

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so-very-very-tired t1_je110j3 wrote

No. Trusses are engineered for the exact specifications of their use. There is no modifying them (short of hiring another engineer to completely re-engineer it all for you).

Also...is that a bed? Is someone living up there? Most roof floor/truss systems aren't designed for actual live loads of people living in the space.

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so-very-very-tired t1_jdrovi6 wrote

The pergola post footings aren’t connected to the house so…no, no issue with the house foundation.

You definitely don’t want a patio sloping towards the house but that’s easy to deal with at install time by properly preparing the base layer (and grading it away from the house accordingly)

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