# Identifying old drywall



## artinall (Aug 14, 2007)

Came across a section of old wall (don't know how old) that was subject to water damage and needs replacing.

These are screwed-on sheets, appear to be 1/2" thick but are very hard. Almost looks like brown paper backing. Can't tell on the frontside (no green paper, etc) But this is old. Not knowing the age of the building.

The material does not powder like gypsum. And you really can't break it with your fingers.

- Isn't old drywall much harder than the new drywall sheets?

- Other than that, there was water leaking on it for some time. Could it have hardened it?

- Is there specially formulated drywall that has been hardened more than normal drywall (other than moisture resistant boards/wonderboard, etc) It is not cementitous.

This is on an outer wall where there is block on the outside. My concern is adhesion when taping and bridging to regular drywall (along if there could have been any reason that a "harder" drywall was specified) There are masonry columns that this abutts on both sides and metal studs this has been screwed to. Cannot determine sheet sizes as of yet.


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## Sir Mixalot (Jan 6, 2008)

Sounds like old plaster board. Pre 1962. :thumbsup:


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## boman47k (Oct 13, 2006)

There was a product called plaster board that was not drywall but actual plaster?


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## artinall (Aug 14, 2007)

Thanks for the reponse Sir Mixalot

If it is plasterboard - what type of board/tape/mix would you patch with? When re-securing this existing board should it be pre-drilled?

There are six and eight foot long sections, about two foot high. 

Pics are from the only sample I have. The image on the left is actually formed with a rounded edge on that left hidden border which is the rightside of right image (flipped).


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## TNTRenovate (Aug 19, 2010)

Drywall...


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## Big Shoe (Jun 16, 2008)

How is the existing paint? Sand/degloss and finish with standard materials.

Screw or nail, whichever works best.

On occasion the plants that make drywall botched up the mixing process. Could be that.

Or Plasterboard?

Good Luck.


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## artinall (Aug 14, 2007)

Assuming it is plasterboard, is it okay to simply use standard drywall and bed mesh tape with multi-purpose compound?

EZ sand? 

Should it be something else like durabond?


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## world llc (Dec 9, 2008)

sponge it down and use durabond or ez sand.


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## artinall (Aug 14, 2007)

world llc said:


> sponge it down and use durabond or ez sand.


And what type of board? These are lengthy sections.


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## Rich D. (Oct 14, 2011)

Is plasterboard the stuff that has a layer of paper in the middle of about 2- 3/8" layers of gypsum or plaster or whateever?


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