# Concrete wall?



## Gary in WA (Mar 11, 2009)

Hi,Greg. *Welcome* to the forum! It appears to be lath and plaster with the final(veneer) coat coming off. The irregular crack and surface spalling can be fixed fairly easily with paper tape and ready mix mud: http://www.plaster-wall-ceiling-solutions.com/old-plaster-questions.html
I'm guessing a 1900-'20 house? Look on your County's web site for your tax/parcel number- lots of personal house info there. 
Be safe, Gary


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## Maintenance 6 (Feb 26, 2008)

Looks like standard plaster. Not all plaster was installed on wood lath. Some is on wire lath and also rock lath, which is like 3/8" thick drywall in 16x48 sheets. Regardless of the lath, the finish is basically the same. Fix it like Gary said. This, however, looks like it has suffered from a moisture problem. You need to resolve that before you repair the plaster, unless it was resolved previously and the paneling was a cheap(?) cover up.


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## c00rdb (Oct 7, 2009)

*Thank you*

Thanks so much for the advice. Just two questions though. The coat is still easily crumbling around the crack. Should I remove all of the crumbling coat first? It might make the hole pretty large. Also the surface on the bottom is very messed up as you can see. If I remove the loose plaster there (comes off very easily), there will be nothing to tape to below it since that will be the very bottom of the wall. What should I do in that situation?

It looks like the moisture problem is from long ago and it was in fact a cheap cover up. Nothing is even damp, just very brittle.

-Greg


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## stuart45 (Jun 20, 2009)

I would remove all the defective plaster first. It's always temping to remove as little plaster as possible when you are not used to doing it, but if it's blown it will come away in time anyway.


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## Gary in WA (Mar 11, 2009)

Enlarge the crack with a hand bottle opener, the pointy end, making the bottom sides of the crack wider than the front. A key of sorts to hold the new material in. As brought out in the article I listed.

Here is some history on plaster with the different backers: http://www.nps.gov/history/hps/tps/briefs/brief21.htm

The crack above to the left of the water damage suggests lath underneath due to the nature of the crack. When lath board under, the crack is different in design. The window trim dates it as mentioned to lath at that time. BUT, I may be wrong, either way, the fix is similar. If a deep area, the article mentions using a bonding agent for the fast, quick-set mud, but not absolutely necessary, just wet with water. After removing *all *the *loose *plaster. The final coat should be with regular drywall premixed mud. 
Be safe, Gary


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