Sand/cement render then plastering a damp wall

[PeaPee]

Hi

The sandstone sill of my bay window was allowing water to pass from outside in and causing the internal plaster to be damp/blister/mould.

I stripped it back to brick, PVA'd then rendered with sand/cement 5:1 with added plasticiser.

I now need to apply the finish coat. Are there any tips/precautions I should be aware of when applying the finish coat?

This is my first attempt at plastering so the most basic advice would be great

Thanks in advance

 

[roughcaster]

Hi

The sandstone sill of my bay window was allowing water to pass from outside in and causing the internal plaster to be damp/blister/mould.

I stripped it back to brick, PVA'd then rendered with sand/cement 5:1 with added plasticiser.

I now need to apply the finish coat. Are there any tips/precautions I should be aware of when applying the finish coat?

This is my first attempt at plastering so the most basic advice would be great

Thanks in advance

First of all, you must be "certain" that you have cured the cause of the water/damp coming in from outside. You did the right thing by stripping the wall, back to brick. You then say that you PVA'd and rendered the wall, "with added plasticiser". Was that a combined waterproofer/plasticiser? "It needs" to contain a waterproofer too, especially in the scratch coat. Did you scratch coat the area first, before you put on the top coat? If you did all of these things, then you should have no problem putting on a couple of coats of multi finish onto the finished render. There might be some suction on the dry render, so it might pay you to lightly wet the area first, to make it easier for you, as as beginner, to get the plaster to spread easier. Good luck, and let us know how you get on. If you have any more problems, then get back to the guys on here.

 

[PeaPee]

Thanks for such a quick response. I added Wickes Liquid Waterproofer to the mix as per the instructions on the bottle.

I thought I would dampen the render with diluted Waterproofer (as instructed on the bottle again) before plastering.

Off to Wickes to take back the excess sand I bought and by plaster. I'll post an update when I'm done

 

[roughcaster]

Whenever you're ready!

 

[PeaPee]

Hi

Finished the job this morning and it doesn't look too bad. It passed the first test when my missus didn't make me ring a professional to sort it out!

Unfortunately I didn't cover the laminate floor very well and have now got smear marks all over the floor after half a dozen mops. Any tips on how to get it clean?

 

[1john]

if it is multi finish and you have got the bulk of it up so there is just a thin film of it you can leave it to dry and buff it off.