Plaster coving installation?

Cut a piece of ply 84mm wide by say 300mm long, use this as a template to run around the ceiling with a pencil as you go, there you are now the 84mm depth is marked out, forget levels as this is now the same as the ceiling, stick it up with a fairly stiff Artex mix. The corners will not be perfect as the room will not be 100% square but you should be able to cut in quite close using a cove jig and fill any gaps with the Artex. Rather than use the odd plasterboard nail here and there support the cove with 50 x 75 x 9mm ply blocks pined to the pre marked line about every metre or so.
Others will have differing techniques but this way works for me putting up 3m length on my own.

 

laser level & ply blocks here.

 

Surely KIAB using a laser level would have problems as you would be perfectly level and not allowing for the ceiling to be this way or that?

 

I do use block & scribe,depends on ceiling, here I skimmed the ceilings, scribed the four corners in 3 rooms,set up laser in each & laser lined up with all 4 marks. either it was pure luck, or my plastering is getting better.

 

The 84mm line is constant all the way around the ceiling and is only a guide line whichever way you mark it out.

 

What type of coving are you fitting and how much does your ceiling fluctuate ?

Plaster coving if fairly unforgiving if you flex it too much. Some of the synthetic (never use polystyrene ) is a bit more forgiving

 

At 84mm drop he's using 127mm cove.
I'm saying go with the pencil line.
If you have already done the living room what's the problem!

 

Use 3mt coving lengths, that will give you less joins

Easier to fit with 2 people but can be done by yourself, as explained above

Joins should be cut at 45 degrees as it's easier to fill and achieve an invisible join - I don't fully understand why but I've coved many rooms and believe me it works better than butt joining

Corners can be a bit hit and miss as rooms are never really square, are you using a profile tool to cut corners or a mitre box

Whilst your fixing up the coving, use the same adhesive, either artex or coving adhesive to fill any gaps as you go. Really pack in the adhesive to fill the gap, scrape excess with a wallpaper scraper and finish with a damp cloth to get a neat line. Don't get too much water on the paper face or it will go soggy and tear

Fill your corners as your working as well. Get as near perfect profile before adhesive sets as then you have less sanding to do. Let the filler partially set and when firming up, easier to shape with a damp blade. Keep working it every 5/10inutes before obviously sets and look at it from floor level as well to get the right profile.

The more coving you fit the better the joins and corners will be

When you say the ceiling is out 15mm in places , is that along a length of coving or you have dips of 15 mm

 

Most ceilings are out by a few mm here and there. That's why I said fill gaps as you go with the cove adhesive

There is a very sm amount of flex with plaster cove, too much and the plaster will crack and cause the paper to ripple. You may be able to flex the cove a little to fit, hold in place with panel pins into wall until adhesive has set. The risk is that your coving is gonna then look wonky

Better to run straight along pencil line on wall and fill gaps to ceiling. Cove and ceiling usually painted white so uneveness blends in

If you have gaps of 15mm though in places, then I don't know what to suggest other than have the ceiling skimmed and levelled before coving

 

No, I recommend getting in a professional, 3 hours work at most.

 

If it's a gradual 'dip' in the ceiling, I'd say push tight there, and gradual push up at the ends(but not fully).

If it's a sharp dip, small distance, I'd hack away a bit of plaster in that part of the ceiling.

Either way loads of adhesive to squash out, scrape off and wipe along.

As for joints, test for fit, then loads of adhesive/joint filler on the joint and fit together, scrape and wipe.

Pre-nail lengths to depth ready to be tacked to ceiling and wall. Remove nails and fill holes once set.

Mr. HandyAndy - Really