Laminate on rock lath plaster ceiling

I bought a post-war story-and-a-half about a year ago. It had some minor water damage, due to ice-dam roof leaks that are so typical of the design. A new roof was put on, about five years ago, and when I bought it the inspector said the interior was bone-dry. But the plaster ceilings have a few cracks and some sloppy patches, made more obvious by a poorly applied textured ceiling.
I "fixed" one bedroom by scraping the popcorn, fixing the cracks with chisel, tape, and compound, sanding, priming, and painting. I'm not really happy with the result.
I've been looking at the second bedroom, and considering my options. I'm leaning towards laminating with 1/4 drywall.
The existing ceiling is built on rock lath, and it's solidly attached. I don't see reason why it should need to come down. The problems are only cosmetic. Beyond that, it's level and flat. I skimmed a laser-level over the surface, and aside from a bit of protrusion where the patch was done, it seems to be at least as straight as I could manage to get with firring strips.
It seems to me that that the drywall would cover a multitude of sins, but that that lumpiness is the one it could not cover. Cracks and depressions would not force the drywall sheets from lying in plane, but a lump would. Not just force the drywall out of plane, but tend to pull the edge of the board so as to make an uneven joint.
So I plan on sanding the patch down until it's in-plane again, and then rent a drywall lift and screw the panels into place. I'm anything but a fast worker, but I think I can manage to get eight panels in place on a single day's rental. Jointing I can take my time at.
I have three main questions.
1: Is this a reasonable way of dealing with the problem? The existing plaster is firmly in place, it seems absurd to go through the work of tearing it out simply to replace it with a lower quality substitute like drywall.
2: What fasteners should I use? Drywall screws? Drywall nails? Something else? Through the plaster into the joists, of course, but how far apart? Should I add additional fasteners along the edges between the joists? In the interior of each panel, not along the joists?
3: How do I treat the corners? Run joint tape and compound along the valley?
Help would be appreciated.
--
Crime is not only a complete disavowal of the social contract, but also
a commandeering of the victim\'s person and liberty. If the individual\'s
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Jeff Dege wrote:

Given your situation, I would call a competent plastering contractor and get an estimate for redoing previous patch work to a better standard. For the inexperienced DIY person, ceiling work is the worst possible introduction to the craft. Sure it will cost some $$ more, but you will be far happier with the results. Remember that butt-end drywall joints always protrude, and plastered surfaces do not, so your preference for the better appearance needs to be taken into account. If you get rid of all the popcorn and texture, the pro repairs could be cheaper. HTH
Joe
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wed, 09 May 2007 11:30:17 -0700, Joe wrote:

Hiring a contractor is out of the question. The choice is between trying to patch, trying to plaster myself, laminating, or leaving it as-is.
--
We can found no scientific discipline, nor a healthy profession on the
technical mistakes of the Department of Defense and IBM.
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
<snip>

Taking the long term view, you have a cosmetic problem in a house that you've lived in only 18 mounths. Might be prudent to ignore it for a while, put away some $$ to go for professional restoration later and during the interim get to know more about your local plastering firms. Your friends and neighbors may have useful information about who is priced right, who does quality work, and so on. Old houses have a habit of developing more urgent non cosmetic problems and working oin these ahead of the cosmetic matters makes good sense. HTH
Joe
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.