raking ceiling & cornice?

[Eastie]

This one has me baffled to say the least.

I've a raking ceiling with about a 6 degree pitch from 2.7m down to 2.4m.
Having a look at the makita crown moulding cut tables for cove cornice, is there any way in which I can factor this 6 degrees into the bevel and mitre settings to achieve such cuts on a compound mitre saw?

Alternatively, given the raking ceiling would it simply be easier to install the wall-to-wall lengths on the two level sides and scribe the ends of the shorter raking sides to match their profile?

:confused:

[silentC]

I've yet to see a plasterer cut compound angles on cornice! They cut them at straight 45 degrees and bog them up with finishing compound. Job's right mate!! ;)

[kiwigeo]

Eastie..if you can sell your house and buy a new one with flat ceilings do it!! Joining cornices on raked ceilings is a P in the A and if youve got a curved ceiling as well like on my place its even more of a challenge.

I ended up using one of those profile jigs you use for fitting mouldings together...its not perfect but you'll get close.

Other option is just to do a trial and error job...I started with the profile jig method but gave up and just did it by trial and error with a bit of plaster to bog the gaps afterwards.

Good luck!!

[Ashore]

For cutting compound mitre cuts I usually build a quick slide that holds the job at the desired angle , in this case 6 deg , then cut at 45 deg

http://www.woodworkforums.ubeaut.com.au/showthread.php?t=18826&highlight=angle

Have a look here at my post on the 30th and follow the links


The trouble with life is there's no background music.



Russell

[silentC]

It's pointless trying to get too accurate with it. The top and bottom runs are going to be out of whack with the side ones anyway because the angle between the wall and the ceiling is > or < 90 degrees, unless you are going to try and install them on the rake too, but I wouldn't recommend that because it will look strange. It's only plaster!!

[ausdesign]

Fit the cornice on the rake first as normal with a 45 cut and then fit the lower cornice by 'kicking' out the bottom. Leaves around a 5mm gap to be filled against the wall but the noticable part - cornice to ceiling - will look right.
With the top cornice you've got little choice but to fill to the ceiling to keep the bottom edges in line.
An alternative is to cut a compund 45 & have around a 5mm step in the bottom edges of the cornice. (but you've still got to fill)
Which ever way you go a right angle cornice into a raked ceiling doesn't go.

[Eastie]

Thanks all for the responses. It looks like a case of trial and error........ oh what fun this will be http://www.ubeaut.biz/toothless.gif

[ausdesign]

& if you got in a professional, 9 out of 10 would possibly say the same thing.

[Auspiciousdna]

The Perpendicular heights is not the same as you can see so it's impossible to make them marry into each other, unless you get some made up!

[Skew ChiDAMN!!]

I've done this at home. The results are passable, but not what I would've liked...

The top cornice, instead of mounting it perpendicular to the wall I raked it to be perpendicular to the ceiling although the bottom cornice was installed in the normal manner. The top edge of the bottom cornice didn't quite meet the ceiling 'cos of the rake but the bead of plaster on the top edge (that's used as adhesive) took up the gap alright. Minimal dressing was needed.

I did not bother trying to mitre these... they were simply left squared right up to the wall.

The two side pieces were installed in the normal manner, except I used an offcut to profile the ends and a small coping saw to cut 'em to fit. Much like I do kickboards! :D Of course, I forgot to rake the profile the first time I tried to cut the lower end, but plaster fills holes nicely. http://members.optusnet.com.au/%7Eamcardle60/Smilies/innocent.gif

There was a small step at the bottom of the lower joints, where the sides hung lower than the bottom cornice but I cheated and "planed" the lower 3' of the side cornices until they met up properly. :o I've since been told by a pro that I should've tacked a stud or similar along the bottom as form-work and plastered in an extended bottom, leaving it to dry and removing the stud later. Somehow I doubt I'd manage any sort of finish that way without running through my entire vocabulary several dozen times...

[seriph1]

Wow - interesting thread, especially with the insights folks have on this issue ......

A lovely pair of box columns that the cornice can run into would win me every time ....... so long as I lived in Athens. But seriously, I imagine this would be a nightmare to the novice or even handy weekend-plasterer. I am pretty certain I have seen it done well, but just where alludes me. I guess if it meant that much to me, I would make up a section that looked like the corner and would practice with scrap (unfortunately there'd be plenty of it!) cornice until I found a method that I found acceptable.

BTW for standard mitres I use one of those $35 mitre saw things...... and that's when I own a table saw, ELU Compound Mitre and a few other bits N pieces. I just never seem to be able to get it right first time with anything other than that little cheapie - I have no doubt it is all to do with my technique.

have fun! I will enjoy watching how it turns out - pics would be great.

FInally, I think this is my thousandth posting - thanks everyone for your tolerance of me and for the brilliant forum. It really makes a diffeRence!