Can't Join Roofs

[adeuley]

I am trying to Join 2 roofs. The large one has a 6/12 pitch while the small one has a 14/12 pitch. I have tried creating opening, I've tried creating the smaller one as extrusion instead of by footprint. I've changed the rafter cut even. nothing seems to get these two roofs to join. Any help is appreciated.

[cliff collins]

Not quite sure what the question is, but I'll try to solve this one:

Are you trying to "join" the two major roofs, and expecting to see the gable "infilled"
by joining them?

If so, that will not work--you will need a Wall at the gable end sitting on the sloped roof--then "attach" it to the gabled roof and it will then "fill in the gable end" .

cheers............

[adeuley]

Yes i want the wall to fill in the small gable but i can't join the roofs. That is the real problem i am having.

[Henry D]

Yes i want the wall to fill in the small gable but i can't join the roofs. That is the real problem i am having.

If you are trying to get the brick wall to infill the gable you have to cut out the portion of the main house roof you don't want and then attach the wall to the gable roof...do the following:


-Join the Geometry of the two roofs (this will make the valley line show up clearly)
-go to top view in 3D
-select the main house roof and then select vertical opening
-pick the valley lines and the edge of the roof (you will get a triangle) ..finish the sketch... the portion of the main house roof under the gable will have been cut out
-select the wall under the gable and attach it to the gable roof

[adeuley]

The problem is I can't join the geometry of the two roofs. I have tried everything I can think of so I feel I must be missing something. I don't think it would have anything to do with the roof having two different pitches but that is the only thing I can think of. You can see from the pdf that there is no valley line between the two roofs. so there is no line to pick when i try and join them so I tried creating a vertical opening in the shape of the smaller roof and tried to join the roofs then all i get is an error message saying the roofs can not be joined. I just don't get it.

[Craig_L]

have you checked that they are the same material?
you can not join 2 different material types (for a stark comparative example one is metal the other concrete) these will never join

[ws]

I normally would make the smaller roof as an extrusion and leave the end short of the apex of the larger roof so that you can use the Join Roof tool to indicate the end of the extruded roof and then the main roof.

If Revit says it will not join and it turns orange then possibly the apex of the smaller roof is slightly above the main roof apex or the bottom edges of the small roof are too close to the edge of the main roof.

I sometimes have this trouble but it can usually be resolved by tweaking the small roof.

To cut out the main roof to allow the wall to join the small roof I tend to use a site plan view set to wireframe which will show the joins to pick the lines for the cutout.

This guide to dormer roofs might help you with the basics of this:
http://www.cadalyst.com/aec/avatech-tricks-creating-dormer-roofs-revit-building-5405

[Joef]

Things I would try:

Make the roof in one piece.
Move the roof toward the middle of the other roof to see if it will join.
Move the roof up and see if it will join.
Roofs are tricky. If the eaves don't line up exactly the join will fail, and with two different pitches, it is likely that the eaves are not lining up.

[Joef]

I'm not sure if you got this roof to join but here are a couple tricks to try.

If you make the dormer roof with a very slightly bigger overhang than the main roof it will then join to the main roof. It can be as little as 1/128".
You can also create the dormer with a two cut plumb and the fascia depth set to zero so that the dormer has a flat bottom. Then line the bottom of the dormer up with the top edge of the main roof fascia.
The roof can also be made in one piece if you split the footprint and use slope arrows.

Hope this helps

[dlpdi5b]

This is one thing I really like about Revit. When you try to create "unbuildable" configurations, it makes you stop and think about how it would really be created by the carpenters. In this case you have two roofs with different slopes with plumb (vertical) cut fascia and that means that each plumb cut has a different height and therefore will not join cleanly to each other. see image below.

You need to think carefully about which roof will be dominant and how the fascia of each will intersect and terminate.

I found that a dormer roof will not join to a main roof if there is not at least a short section of the side dormer fascia that is level. This can be very short, just an inch or two. Another way to explain this is that in a plan view, the left and right edges of the dormer have to have a short length where they are parallel to each other; you can't have a dormer that is two triangles in plan. Or at least I haven't figured out how to do that yet.

The other tricky issue is where you have two pieces of sloped fascia coming together at the corner. They will not join in real life that way without a short level section. Again, think of the plumb cut heights; they are different if the roof slopes are different. You need to create a short level section to allow the transition.

Hope this helps.

[river0013]

I just dealt with a similar situation....had been working around similar situations for a while, but I figured out the answer while I was looking at this posts.

First I set up my smaller gable roof so that it extended well into the main roof and so it completly intersects the main roof. Then I join the roofs using the Join Geometry tool (NOT the Join/Unjoin Roofs too)- this will show the valley line in the roof plan. Go to your roof plan and edit the smaller gable roof that lays on top of the primary roof. Edit the footprint so that the footprint follows the valley lines. That worked for me.

[Richard - CSG]

Alternatively, you could set your smaller roof fascia at the same level as the main roof. Also, check to make sure they are both plumb-cut, or square-cut.

[river0013]

Alternatively, you could set your smaller roof fascia at the same level as the main roof. Also, check to make sure they are both plumb-cut, or square-cut.

In adeuley's case that might work, but my method will work if the roofs have different fascia levels also. Not sure what his design intent was. In my case I have a gable roof that is set back 1ft from the fascia on the main roof, If I wanted the same fascia/eave height I would just set it up as one roof- the key to making a roof with multiple roof pitches is the align eaves tool. make sure every eave is aligned or it won't work.

[patricks]

I personally don't like to sketch a roof footprint manually to follow valley lines. For one thing, there are just too many things that can change throughout the course of design that can break the roof intersection, where it either cuts into the main roof again, or doesn't touch it at all. Then you have to keep adjusting the dormer roof over and over. Also you end up with vertical fascia edges along the "valley" edges of the dormer roof, which are not desirable in section. The edges don't follow the slope of the main roof.

In my experience, the roof join tool usually works better if you can start with a piece of the dormer roof that does not touch the main roof at all. Just a little sliver, as was mentioned above, when the short edges on each end being the slope-defining lines. Then use the roof join tool to stretch the sliver back to the face of the main roof.

[LuckyLasVegaz]

Thank you for that explanation, it makes perfect sense!

[NAOMI BRYDEN]

Hi All,

I have read this thread looking for an answer to my problem of joining roofs together.
I have tried several methods of re-drawing including - an entire new roof, using the dormer tool, using the slope tool in sketch outline mode and creating a slither of roof and joining using the roof join tool.

I have given up!

I attach a pdf for an image of the roof in question. As you can see I have successfully drawn 1 dormer. There should be another identical dormer along the same elevation.
The plan image indicates the partially successful method used. Namely;
1.drawing the outline in sketch mode
2.giving the relevant pitches to the relevant edges
3.using the define slope tool to create a dormer pitch within the main roof
4 using the join walls tool to fill in the wall element of the dormer.

As you would expect I then tried to repeat this and I just cannot get another dormer in this roof! Any/All suggestions welcomed and thank you for your time!
105743

[PijPiwo]

Can you upload your roof? I cannot recreate your issue here, all working good on my end.