Replacing water damaged plasterboard

[richards1978]

Hi everyone,

We've had a leak around the seal of our shower upstairs (silicone failure), which has then resulted in water pouring onto the ceiling in the kitchen to the point where the kitchen plasterboard has now bowed and started disintegrating.
I've now re-siliconed the shower, and pulled down the disintegrating plasterboard and it looks like all leaks are now fixed.

However, I have a question on replacing the plasterboard in the kitchen. It is a fairly small piece of plasterboard in the corner of the room, and measures about 1.2m by 0.8m with supports already in place around the edge.

If I fit a new board in its place do I need to do anything special where the new board butts up against the old/existing board - should I chip away some of the existing skim on the old board and try and remove the old scrim tape, so fresh scrim tape can be used to join the new and old board or is this not necessary?

Thanks
Rich

 

[Wayners]

I do scratch back the old tape and plaster with chisel or tungsten scraper.
I like to put it the new tape below the surface with nothing on the existing surface if that makes sense.
No visible bump then.
Seal the new plasterboard and the old plasterboard edges with PVA. Wood glue will do. Stop the filler shrinking.
You can cut scrim with scissors to make narrower if you want and a box of toupret powder filler will do it

 

[richards1978]

Thanks for the quick reply - something like you are suggesting was along the lines of what I was thinking.
Sounds like it's worth a go, and I'll give it a try with a wood chisel.

 

[Ollyfp]

Wayners knows. Also, maybe rethink your shower seal setup. Silicone is used far too much if you ask me... which you didn't. Lol