Need help creating T&G

Hi, I hope I’m posting this in the right place. I have to create a T&G roof along the sloping wall / dormer wall. Is there an easy way to do this? One by one is gonna take forever and drive me mad.

There is no trim around the edge so the connection between the panels has to be clean.

Doing it this way doesn’t look too great and takes too long. I’d appreciate any help, if possible.

Thank you

PS: I’d put an example of what I’m doing but I’m only being able to post just one image.

It would be more simple to help you with a model instead of many images.

Sorry, what would be the best way to upload the skb file?

Select the file you want to upload by clicking on the up arrow in the reply box. It’s the 7th icon from the left and you shoulld select skp files and not skb files if possible…

After you click the up arrow, just follow the on screen prompts to finish the process.

Also, upload the .SKP file (the .skb file is the backup - the version previous to your most current save).

If the file is too large to upload directly here (there is a limit), you can put it on the Extension Warehouse and post the link here.

Materials are generally not modeled in SU. Instead, image-based textures are used. Using textures is preferrable for several reasons: it’s faster and easier; it looks more realistic; it results in a more compact, responsive model. I’m sure you could come up with (find or make) a texture that would give you the look you’re after. Further, it seems to me that the tongue and groove, unseen internal features, don’t really enter into it–that’s more the province of a specification than a model.

The only logical class of exceptions to the general practice of using image-based materials, I think, is when the thing you’re designing is e.g., the tongue and groove panel itself, in which case the geometry of the material is not only relevant, but the whole point.

Could you elaborate on why you wish to model the T&G panels rather than simulate their appearance?


They want to see how the connection of the panels between the dormer wall and the sloping ceiling wall connects. It’s more of a technical detail thing rather than just the overall look.

Help_Dormers T&G.skp (1.3 MB)

Here’s the file. Thanks in advance

How about making a separate detail view instead of trying to show it in the larger model?

When you say “roof” I presume you mean “ceiling,” right? When you say “T&G,” are you talking about individual tongue and groove boards or T&G paneling?

What is the actual problem you are encountering?


Yeah, the ceiling. I mean each individual panel that would have to match and connect between walls. It’s not exactly a problem. I can do it, it’s just taking very, very long. I was wondering if there was an easier, faster way to do it. Maybe some technique I don’t know that I could use.

When i have modeled T&G in the past, I created a component that was JUST a 4x8 rectangle extruded to the proper length. Then I placed the first piece at the appropriate start point, and used the Move tool to copy the width of the piece and then the “X#” command to create an array of sheets. Then I copied the array, and placed the end staggered from the first piece. Once I did this a couple times, I had a bunch of sheets covering the roof. only then did I edit the component and create the tongue and groove geometry. After that, I selected the pieces that needed to be cut to align to the roof, made them unique and modified their geometry as needed.

Hope that made sense…

Unfortunately you cannot do want you want without having individually manufactured t&g planks for use in the curved dormer ceiling.
Assuming all of the main slopes are the same they can all use the same width boards.
But if you want the joints to align as they go into the dormer their thickness must vary to accommodate the curving surface. Some must be narrower, some must be wider.
Also they need to be bend around the curved form too - it’s not impossible, e.g. by kerfing the backs with saw cuts, but in the real-world making it would be a real pain.
I think you really need to use a trim around the dormer’s edges and accept that the boards’ joints will not line up

I made this lash-up using a large grouped face place on the floor, then array-copied at 4" vertical centers [I know it’s not the actual size on the slope, but it’s just for illustrative purposes!], then I selected the ceiling faces and intersected them with the grouped faces.
Note how the dormer’s ceiling needs ever wider planks as it rises and they are all curved too…
I suggest that t&g is not the appropriate material for this ceiling.
Try plaster !

Woah! It’s early… I posted before seeing your attached file. You could still sheath the flat surfaces with components, then cut as needed… the curve would be rough with T&G. Is this something that you have done before? I think I’m with Tig on this one, it might be tough to get the material around that tight of a curve…

Wow! Thanks a lot. Super helpful. I brought it up to them. It’s hard to imagine without visualizing it. We’re probably gonna go with a trim so we don’t have to worry about the connections matching. Thanks so much

That shape is going to be impractical to apply T&G since the semi-circle you’ve based it on is smaller to one end than the other - each slat will have to be shaped.

A simple change in the geometry would make it much more practical; see attached.

@gadget2020’s method looks something like this…

Note with the simplified ‘constant-cross-section’ dormer and with its equal sized planks, their joints will NOT align with those in the flat slopes.

So you need to introduce a ‘trim’ around the junction to mask it… which is another issue altogether…

my 2 planks are slightly different sizes, i.e. a quick lash up…

but as Tig points out they can never lineup due to the angle of intersection…

heres the skp I made with texture…

dormer.skp (181.7 KB)


Thanks so much for the replies, everyone. Truly helpful.