Patching Plaster wall over very old plaster

[aspenglow]

Hi,
I am new here so please forgive me if this question has been asked before. I wish to fix up old plaster walls. The plaster on the walls is the old kind where it has horse hair in it. First of all is it better to pull out this plaster and replace with gyprock sheets or does it patch up OK with normail patching techniques. I am trying to save money like many DIY people. Would appreciate an answer. Thanks!

[rod@plasterbrok]

If it should be replaced or not, would depend on the condition its in and how good you want it to look etc.

Typically, fibrous plaster sheeting can be patched up ok providing the sheets are still solid, in reasonable condition and have not got "baggy". I consider baggy when the sheet can easily be pushed it between studs or ceiling joists. This is not that common but can happen it the wall has been knocked about or has a lot of crazed cracking. Crazed cracking is lookes a bit like a spider web on the wall, small fine cracks going off in alll directions.

If this is the case then replacing is the best choice.

The other problems that occur with fibrous plaster is nail heads showing, joints cracking and picture rail removal. All of these things can be fixed up ok.

The problem fixing cracked joins is over filling, as the joins don't have recessed edges like plasterboard all joins are like plasterboard butt joints. Mostly these joins were face scrimmed by cutting a v in the join and filling the v with sizal and trowling flat. The trouble is not all joins were flat. To tape these joins and get a reasonable finish they should be scraped back as flat as possible first. Not an easy job. I think running over them with a belt sander with coarse grit paper would do the job quickest.

Or else be prepared to trowel the joints very wide to get a good finish.

Where a picture rail is removed the sheet on the bottom will be 10mm thick and the sheet on top 8mm thick therefore you need to trowel wide up toward the ceiling to get a flat looking finish.

Where nail head are showing you need to put a new screw or nail beside it and finish off.

Cracked internal corners can be fixed simply by taping as you would plasterboard.

Cracks around the cornice are best repaired with a good quality paintable sealant. Apply the sealant along the crack and wipe over to smooth it out with a wet sponge.

Hope this helps.

Cheers Rod

[aspenglow]

Thanks so much for your advice. I have see your videos on You tube. Absolutely great!!!!!!

[rod@plasterbrok]

Thanks, good luck with the job.

Cheers

Rod

[seriph1]

WELCOME TO THE FORUM!

:D:D:D

I met with a person the other day whose family hails from Bendigo and have a plaster manufacturing business there. I believe their name is Bynon Industries. I don't know if they could actually help personally, but I feel certain they could steer you in the right direction for some more excellent advice.