Best way to build attic storage room in a house with roof trusses?

[Tammlen]

 

(new user of HD 2021)

 

Hi, got another question. This old house we are renovating on our farm has a simple one story structure.  It is basically a box, with a gable roof at a 6 to 12 pitch with howe-type roof trusses set 24" oc.  This 80+ house has survived at least two moves from where it was originally built, and still holding together remarkably well (all 2x4 and 2x6, 24" o.c., construction).  Inside we have removed all the old drywall and insulation.  It's down to bare bones. We will be DIY renovating it, plus building on two additions.  

 

So far, I have managed to replicate it's basic one story structure and truss system in HD.  But I want to have a third of the trussed roof space to be an attic for storage and to set an ERV.  The other two thirds of the roof will be left open in a poor man's version of a vaulted ceiling with trusses.

 

I can't just define this attic space with a ceiling from the floor below, as it will not be able to hold any real weight.  And we don't want to change anything with the existing roof trusses or put any additional weight on them.  The building inspector would have a fit and we don't want to have to hire a structural engineer.  Best to just leave them alone and let them do their job, which is holding up the roof.

 

So my idea is to build a strong self-supported attic floor, with its I-joists set in between the existing trusses and slightly below. The ceiling for the rooms below, and the flooring for the attic, would be attached to these I-joists, not the trusses.  The old trusses would basically "float" inside the new floor with nothing touching them.

 

 I have been trying to build this floor by creating a second floor, whose height is basically "zero".  But still struggling a bit with the elevations.

 

What I am trying to do is create a "loft", except it will be walled off and have trusses sticking out, and only used for storage.

 

Is there a better way than what I am doing?  Or a video that might help me?

 

Would appreciate any suggestions.  Thanks!

 

 

[solver]

13 minutes ago, Tammlen said:

I can't just define this attic space with a ceiling from the floor below,

 

Why not?

 

You can define the ceiling structure to be what you need, I believe.

[Tammlen]

If all I wanted was to create a pretty picture of a ceiling and a floor, you are correct.  But I'm not interested in pretty pictures.  What I need is to plan out framing construction for a specific storage load capability, along with electrical, ductwork,  etc., that will be needed in the attic space.  And I found out you can't do this in HD, unless this space is set up as a room on a second floor.

 

But I did locate some instructional videos on trusses and lofts since posting this.  And If anyone is interested.... I was able to create what I needed in basically a three step process...

 

1) First build just a one story structure, with the walls, floor, roof, etc., exactly as needed (that's important, since if you change things later on, the roof trusses don't auto-change to match.)

 

2) Use object editor and delete the auto-generated framing for the roof, ceiling, walls, floor (which also turns off auto-framing).  Then use framing tool to draw the roof trusses (be sure to turn on roof truss display in 3D object list so you can see the trusses).  Once you have trusses exactly how you want them, then rebuild the framing for the roof, ceiling, walls, floor (again, be sure to get the trusses exactly how you need them before step 3, because any changes later on will be a real pain to fix).

 

3) Then finally, when everything looks good, create a second floor.  I found the height of the second floor doesn't matter.  The roof plane will automatically snap to the top of the trusses.  So even though your home is now a "two story" structure in HD, it will basically look the same as the one story rendering.  But now you will be able to work with the attic space like any other room.  Can modify the floor framing and place engineered floor joists or floor trusses as needed for a strong attic floor, and place other objects as needed, which will now show up in material lists.

 

Anyway, that's how I did it.  There might be a better way, but this worked for what I needed.

[carlmega]

I think you are on the right track. I checked through YouTube while I was reconstructing my attic space and I found some really useful videos. You can also do same.

If you, however, need pull down stairs for your attic, you may want to check https://theconsistent.com/best-pull-down-attic-stairs/. They have top quality pull down stairs for use