Doug_N

2 x 6 ceiling joists may be able to support a floor, depending on the span of the joists. Typically, ceiling joists are joined over a wall which may not be a actual load bearing wall because of support from the structure of the first floor. I would recommend that you contact a structural engineer to review the loads that will be imposed by your proposed attic room. That may be the best money that you spend on this project. The cost shouldn't be prohibitive for a short meeting. You should also see if a building permit would be required for the contemplated construction. If one is required, and you don't apply for one, and a neighbor complains, it could get very expensive quickly.

One more hint, if you have a second floor with a roof that ignores the upper floor, make sure that the floor area has a room height definition that makes sense, and that a flat ceiling is part of the room DBX. Also make sure that the open to below area stairwell has the same ceiling height as the rest of the room.

Hi Mackenzie, I sorted out some of the problems that you listed in your post and adjusted the stairs a bit. The pictures posted here were not my final version of the plan file (also attached) but it may help you get to the goal that you are trying to achieve. I have suggested a 7' ceiling to get the widest flat ceiling practical using the 12:12 pitch that you mentioned. It is not possible to see what the ceiling joists are for the first floor, but you should make sure they are sufficient to support a typical residential floor load. Attic Walls.zip

CA is a great tool for doing interior design. I often sell my projects based on a few interior renderings.

This was just a very quick concept edit to see if this is in the direction that you were looking for. There is more work to be done if you would like this to be a gull wing roof, working on the design with auto roof builds turned off. sample.zip Untitled 1.zip

Post your plan file so that the error can be analyzed.

Hi Mackenzie. First question is are you sure about the slope of the roof. What is the actual pitch of the roof, and do the rafters sit on the ceiling plate of the exterior walls? Using the model that you posted there isn't anywhere in the attic that would give you enough ceiling height for what you are talking about. Here is a cross section of the highest part of the attic. I changed the floor thickness to 2 x 8 floor joists (probably what was used for the ceiling joists) but that is just a guess. I also reconfigured the stairs to have 10" run and about a 7" rise. You can set your desired attic ceiling height to, say 7', and set the roof default to ignore the upper floor. Now you can create walls that will fit between either the bottom surface of the roof or the ceiling height of 7', whichever is lower. But first you need to make sure the model of the shell of the house is correct, including the roof pitch. I suspect the pitch is more like 16:12 or so. If you want to do new floor joists, and leave the ceiling joists undisturbed, they you just the method that Eric suggested, setting the ceiling height of the second floor to 1 inch or so, and then create a 3rd floor. That would also slightly raise the roof, but then you can lower the roof by the same amount that it got raised by adding the new floor. Do a before and after cross section printout to determine the amount that the roof got raised to figure out how much to lower it. Hope this helps. Attic.plan

Here is the code for winders in stairs in Canada (using the Ontario Building Code version). Here is what the code says about the narrow end of tapered stairs (as in winders). Ontario Building Code - Volume 1, O. Reg. 332/12, Article 9.8.4.3. of Division B 9.8.4.3. Dimensions for Tapered Treads (1) Except as provided in Sentence (2) and Articles 9.8.4.5. and 9.8.4.5A., tapered treads shall have a run that, (a) is not less than 150 mm (5-7/8") at the narrow end of the tread, and (b) complies with the dimensions for rectangular treads specified in Table 9.8.4.1. when measured at a point 300 mm (11-13/16") from the centre line of the inside handrail. (2) Tapered treads in required exit stairs shall conform to the requirements in Article 3.4.6.9. (3) The depth of a tapered tread shall be not less than its run at any point and not more than its run at any point plus 25 mm . Ontario Building Code - Volume 1, O. Reg. 332/12, Article 9.8.4.5. of Division B 9.8.4.5. Winders A-9.8.4.5. Winders. (1) Stairs within dwelling units are permitted to contain winders that converge to a centre point provided, (a) the winders turn through an angle of not more than 90°, (b) individual treads turn through an angle of not less than 30° or not more than 45°, and (c) adjacent winders turn through the same angle. (2) Where more than one set of winders described in Sentence (1) is provided in a single stairway between adjacent floor levels, such winders shall be separated in plan by at least 1 200 mm (47 -1/4").

It would be really important to talk to a code expert about the winders doing 180 degrees. Most authorities only allow 90 degrees.

Steve beat me to it, but my post has nice pictures!

Ok so your problem with the garage curb wall is that the 6" width starts at the exterior edge of the slab. Take away the brick ledge and you are left with just a sliver of curb to support the framework.

In regards to what Eric said, the layout file does not contain a copy of the plan file, just a link to it that is a relative link. The link only works while on your system. When posting files, the minimum post for CA is the plan file.

Managed to get it done. This was really tough to do though .

Steve, great video, thanks for that!

I know how frustrating this can be when a dormer works in one location but not in another. There are probably lots of things that the automatic dormer tool checks for, such as interference with other building elements that are not apparent to the user. Fine tuning the parts is a bit of an art, and that is why this user group and some of the magicians here are such a great resource.

Yes, I forgot that setting. Good catch Brett, That helps a lot with this.

Here is a bit of fiddling with your design (Going to be a great house by the way) 221-Linwood-EC-COPY2.zip

That is what I was fearing. That makes the creation of construction documents soooo much harder.

In your survey you only asked if the user was a licensed architect or not. There are also (for houses) other licenses that allow for designers to design small buildings. My license is like a very limited architect's license. I am limited to 6,400 sq ft footprint and not more than 3 storeys. That leaves a very large market for me to practice in. I have tried to use Revit for house design, but it is really difficult to do, and really time consuming. While it is more flexible than CA, that flexibility comes at a very high price with the time to be proficient and the time to build a library that is useful in this field. At least in my opinion.

I am trying to make a mansard roof entrance with the barrel arch as illustrated, but I can't seem to make the curve eave edge. Anyone have a method for doing this?

Is this what you had in mind, or is the roof all on the same plane?

Well, using Revit to do a garage? Kind of filling a hand basin with a fire hose!

Do you mean that the flat roofs have different heights as well? Could you post a copy of the plan file?

None of the winders in the examples could be used in my jurisdiction, or, I suspect, anywhere in Canada. Wok-cz example doesn't count because they are not winders, and would be allowed. Here is the code for winders in stairs in Canada (using the Ontario Building Code version). Here is what the code says about the narrow end of tapered stairs (as in winders). Ontario Building Code - Volume 1, O. Reg. 332/12, Article 9.8.4.3. of Division B 9.8.4.3. Dimensions for Tapered Treads (1) Except as provided in Sentence (2) and Articles 9.8.4.5. and 9.8.4.5A., tapered treads shall have a run that, (a) is not less than 150 mm (5-7/8") at the narrow end of the tread, and (b) complies with the dimensions for rectangular treads specified in Table 9.8.4.1. when measured at a point 300 mm (11-13/16") from the centre line of the inside handrail. (2) Tapered treads in required exit stairs shall conform to the requirements in Article 3.4.6.9. (3) The depth of a tapered tread shall be not less than its run at any point and not more than its run at any point plus 25 mm . Ontario Building Code - Volume 1, O. Reg. 332/12, Article 9.8.4.5. of Division B 9.8.4.5. Winders A-9.8.4.5. Winders. (1) Stairs within dwelling units are permitted to contain winders that converge to a centre point provided, (a) the winders turn through an angle of not more than 90°, (b) individual treads turn through an angle of not less than 30° or not more than 45°, and (c) adjacent winders turn through the same angle. (2) Where more than one set of winders described in Sentence (1) is provided in a single stairway between adjacent floor levels, such winders shall be separated in plan by at least 1 200 mm (47 -1/4").