How to make cornice corner joints with a raked wall?

[ironbark]

Hi, I’m about to install 75mm Gyprock Cove Cornice. I will have to make quite a few internal and a couple of external corners.I have sloping ceilings,ie raked walls. All the ceilings have a 4 degree slope. 
Any ideas as to how to make good joints would be very welcome. Do I have to make up some jig with a mitre slot for my saw or is there an easier way?  It’s been a long Christmas break and my head is hurting thinking about it. I do like challenges 😊.

Many thanks

[Jewelleryrescue]

Hi  @ironbark 

Hi  @ironbark 

I feel your  pain I hope I can help.

All the corners still 45 degrees cut as per normal.  The top edge of the cornace edge length might need chamfering at 4% to match roof angle.  

Why cant you simply fill any gap  or lip at the top  join?  I know you must have your reasons not seeing you  problem  first hand I know you will forgive me.

[ironbark]

Thank you for that. I think I’m going to  cut off a couple of short lengths and play around. I do have a very large number of corners and so need to work out a quick repeatable cut; I don’t want to be fluffing around filling each joint. I was toying with the idea of making up a jig/mitre board with a build in 4degree slope so I’m able to cut both ends of the sloped edge. I haven’t got my head around it yet still plastering at the moment!

cheers Jan 😊

[Jewelleryrescue]

Hi @ironbark 

can you take a picture of the profile (the end of a cornace piece)  So I can try understand  better  thanks  Not giving up on you yet

[ironbark]

Hi Jewelleryrescue,

Thank you for your maintained interest 😊🙏.

It is a very uncomplicated cornice as you’ll see. It’s basically semi circular with a very small flattened section on the back; this flattened bit obviously isn’t really relevant. Hopefully when it comes to the practice my concerns will feel misplaced! Thank you again.

 

 

 

[MitchellMc]

Hi @ironbark,

I don't believe the 4-degree slope of the roof will necessarily change the angle of the mitre substantially. I'm a very visual person and would cut two pieces at the standard angle and place them against the ceiling. If they don't mate up correctly, make small adjustments to each to get everything lined up perfectly. Take those pieces and use them as a template to make your jig. Replicate the cut on the other pieces with the jig.

Even without the slope of the roof, filling the joint between the cornices is typical for a perfect fitment. Walls are not 100% square to each other, so some amount of filling is always required.

Please let me know if you have questions.

Mitchell

[ironbark]

Thank you Jewelleryrescue & Mitchell, 

I’m thinking it’ll work out OK 😊. Always looking ahead at jobs yet to be tackled in case I need to resolve any issues. I agree now, I think my concerns were unwarranted!

Thank you both for your contributions.

Jan 😊

[ironbark]

Hi Jewelleryrescue,

The above project with the cornice and the raked ceiling had to be postponed but was tackled yesterday and today.  You were correct in your first response; my initial concerns (over thinking it 😁) were unfounded and the reality was that with a little tinkering with the coving adhesive those gaps created by the four degree raking were easily resolved!

I’ve done plenty of DIY and landscaping in the past and have always just resolved issues in a practical sense when they popped up! Now much older, I’m tending to overthink issues 😆.

Thanks again for your interest.

[Jewelleryrescue]

Your  welcome  @ironbark 

You have done well overcoming another little DIY  glitch we all face. 

 Now your older and wiser   thinking is what will help you grow faster.  It will save you time, money and help you not make  mistakes to often this knowledge will aid you in further  projects/  Your thinking  will  over come glitches speed up as your experiance builds on top of  each project. Next time you are faced  with similar issue you will have it nailed