Sloping coreslab roof

[mjl]

I have a sloping core slab roof to put on block walls. It slopes 8" front to back over 32ft. What is the best way to go about this?

[Scott D Davis]

create the roof using the Pick Walls tool, set the roof at the 32 FT level (hopefully a level you have set up called Roof at 32') Draw a roof Slope Arrow while still in sketch mode from the side that needs to stay at 32', to the opposite side where it needs to be 8" lower. Right click on the slope arrow. Height at Tail should be set to "32 ft roof" or what ever you've called it, and height at head should be the same with a negative 8 inch offset. finish the sketch, and you are done.

[mjl]

Thanks,
The 32ft is the length of the roof not the height.
I have one problem still. When I look at it in section the head is 8" thick and the tail tapers to a point. I need to maintain the 8" throughout. Is this to do with the family I used. Can you suggest which one I should use to modify to a coreslab.

[Scott D Davis]

If you used the roof tool, it wont taper. it will be 8" throughout...32 FT length, I just read that more carefully. When you say it tapers, are you looking at it in section or elevation. In elevation, part of the roof could be inside the walls, thus appearing to taper. Drop a section line across the roof and look at it. You may need to lower the whole roof to fall inside the walls, to form a parapet.

[mjl]

I have it in section view. Does it have anything to do with plumb cut ect. or the fact I based it on a rafter family.
I changed to floor and put a floor slab for the roof and it appears to look fine. Is this o.k. to do?

[Scott D Davis]

Yes, you used a roof family, but set it to rafter plumb cut, and probably have a fascia depth set, so it cuts the rafter bottoms to that depth. You can use the floor as a roof, but walls wont attach as you expect. Go back to the roof, and change the settings to rafter>plumb cut>fascia depth = 12" see if that does it.