On Sat, 8 Nov 2008 08:47:25 -0800 (PST), "
wrote:

I'm putting up timber stud partitions, and need to screw several top
plates into the loft joists in a lath and plaster ceiling (working
around various exposed features).

For a bunch of reasons, access from above is not so easy (not
impossible, just awkward).

My stud detector just bleeps everywhere (because of the laths and
nails).

The only thing I can think off is to drill a few test holes with a
fine drill (e.g 3mm) until I hit a loft joist. I reckon I could end up
doing a few of those for each fixing point, as the loft joists are not
very accurately spaced (Victorian building).

Yes thats the way to do it. Just be glad that you have some access
above so you can get an idea of the spacing and direction of the
joists. I once worked on an old building with no access above and
where the joist direction changed midway across the room. It took me
ages to realise what was going on

Its worth putting a skirt around the drill bit so the chuck doesnt get
bunged up with mortar

When you have finished fill the holes with polyfilla

Anna
--
Anna Kettle
Lime plaster repair and conservation
Freehand modelling in lime: overmantels, pargeting etc
Tel: ***(+44) *01359 230642
Mob: * (+44) *07976 649862
Please look at my website for examples of my work at:
www.kettlenet.co.uk *