Patch of hollow plaster, uncovered unknown material... help!

[Petebriz]

Hi all,

Firstly this is my first post so please bear with me.

After removing some horrible shelves in an alcove in preparation to re-paint and spruce up my dining room I've discovered a patch of plaster that sounds very hollow when knocked (the wall around it sounds fine). After painting it white in preparation i noticed a darker patch was showing through so new that further investigation was needed. I cut out a little section to investigate what was underneath, the top layer came off very easily and underneath looks like a sort of cement which is also crumbly (see attached photos).

I was wondering if anyone could identify what this is and the best way to go about fixing it? The total hollow sounding patch i about 30 x 45 cm. Please note that the images are displayed horizontally when they should be vertical.

dining room alcove 1

• Petebriz
• 21 Jun 2012
• 2

dining room alcove close up

• Petebriz
• 21 Jun 2012
• 2

dining room alcove 3

• Petebriz
• 21 Jun 2012
• 2

Many thanks in advance.

Pete

 

[peaps2]

Looks like lime ash to me. How old is the house?

 

[Petebriz]

I think it was built about 1880 to 90

I've had other rooms stripped back and replastered and this wasn't apparent with those rooms.

Any ideas what could have caused the patch to appear and how to go about fixing it?

Thanks,

Pete

 

[Micilin]

Would you say this is a internal, non load bearing wall?

 

[Petebriz]

Nope, this is the far corner of the house.

 

[peaps2]

Inspect your gutters and drain pipes to see if they are ok. Look at the pointing or render on the outside as well. Looks like you have a damp issue as well.

Ash lime was commonly applied to outside walls (gable-ends) to add strength to the wall.

When you have sorted the damp issue out you can hack off the blown plaster and re-do it, I would use lime render and add some the the skim.