To tape or not to tap hairline plaster cracks?

[RicodJour]

None of the above.

Plaster shouldn't be painted for about a month, so don't using plaster patching compounds unless they specify a much shorter time for finishing. Better yet, don't use plaster patching compounds at all.

Digging out hairline cracks is a waste of time. You want that hairline to disappear, making it larger is a strange way to go about doing it. That advice comes from years gone by and is for larger cracks.

The best stuff to use is called Krack-Kote. It's fast to apply and dries quickly, hardly _any_ buildup at all so there's no hump in the wall like regular drywall tape and compound would give you, it's available in regular paint stores and you can paint over it almost immediately.

I suggest you keep the door closed while you're working, emerge periodically to yell and curse about what a _bitch_ fixing those cracks is, leave stuff all over the room, and milk it for all it's worth. Don't make it look too easy. ;)

R

[Fred]

If its only hairline cracks you could skip the patching process and use Kelly-Moore elastomer paint. I'm sure other companies make it too. This paint dries like a sheet of rubber and does not crack. I've used it on exterior sun damaged wood with thousands of cracks and splits, no patching required - 10 years now and still looks good.

[blueman]

Our 100+ yr old plaster lathe walls from time to time develop hairline cracks.

Googline, I see that some DIY articles recommend taping and others say that for hairline cracks it is sufficient to dig it out and fill with drywall or plaster patch.

Since taping takes more time and coats to feather out nicely, I would like to know when (if ever) is it sufficient to just dig out the crack and patch it without tape? (assuming that I want the crack not to open up again)

Also, is it better to use plaster patching compound or drywall compound? (the plaster patching compound drys much harder but is therefore also harder to sand down)

Thanks

[Amun]

Those DIY articles are meant for one or two cracks in an otherwise solid wall.

100+ year old plaster can be simply deteriorating, and many hairline "spiderwebs" through a wall usually indicates the plaster has broken away from the supporting lath.

Wallpapering can buy you a few years.

Like everything else. there comes a point where patching just does not work, and total restoration is the only real fix.

You just remove all the old plaster, and re-plaster, or drywall.

But only you can see if the wall is bad enough to need that.

AMUN

[Norminn]

clipped

Plaster lath can be re-fastened, I believe, if not in bad shape. I would try screwing a couple of laths back onto the studs long before I papered or replaced it. I like old stuff :o) If the hairline cracks are only that, and you don't have a lot, any wide cracks or bulges, I would just smoosh in some paintable caulk, wipe with damp cloth, dry, paint. If cracks reappear soon, or there is a pattern suggesting a whole wall or section is failing, I would think about more serious measures. The point is to cover the fine cracks with something flexible so they don't come through the paint, esp. at corners.

[blueman]

Luckily, the plaster is otherwise in pretty good shape -- a bit bumpy in areas where others have patched previously or maybe where paint has accumulated over the years, but the walls themselves seem pretty firm with the plaster well-adhered to the lath.

Not too many hairline cracks, mostly in understandable areas like in corner or near windows.