Want to paint rendering but there's moss on it

TomsMom

The rendering on our porch (which has never been painted before and is a dirty grey/brown colour) was very damp and there's a lot of moss growing on it where the sand has lodged between the little stones (we live at the seaside).

I've killed the moss and it's now turned brown. The cause of the damp has been remedied and the rendering has now dried out nicely. I now want to paint the porch with Weathershield to match the rest of the house which we recently painted.

I've brushed the rendering, lots of loose dirt/sand is coming off but the dead moss is stuck. Do I need to remove all the dead moss? Or can I paint over it?

I've been scraping some of it out with a plastic scraper but a lot of the stones are coming out too.

Atelier

You need to get the old moss out otherwise your paint is not going to adhere properly.

Have you thought about a jetwasher to blow all the moss away?

TomsMom wrote: »

The rendering on our porch (which has never been painted before and is a dirty grey/brown colour) was very damp and there's a lot of moss growing on it where the sand has lodged between the little stones (we live at the seaside).

I've killed the moss and it's now turned brown. The cause of the damp has been remedied and the rendering has now dried out nicely. I now want to paint the porch with Weathershield to match the rest of the house which we recently painted.

I've brushed the rendering, lots of loose dirt/sand is coming off but the dead moss is stuck. Do I need to remove all the dead moss? Or can I paint over it?

I've been scraping some of it out with a plastic scraper but a lot of the stones are coming out too.

Lorian

Yes you need to remove it as suggested. Then make good the surface (I'd recommend the self-mix exterior powder, B&Q own brand or Polyfiller) and then paint with a paint with anti fungal/moss properties. Dulux do one, and other brands like Machphearsons marbletex/powerkote.

Antispam

You need to remove all moss completely

If its on the rendering polyfiilla do a waterproof exterior filler its its in the mortar you can get ready mixed mortar from B&Q for around a couple of £ and mix with water and fill in and let it dry for a few days

If the surface is unstable you may need stabilizing solution before painting

jockster211

Hi

Try some soapy water & a stiff scrubbing brush? Or as someone already posted maybe a pressure washer?

TomsMom

Thanks everyone.

I brushed and scraped, brushed and scraped and it looked as though it had all gone.

Have done 2 undercoats and one top coat of Weathershield and it looks as though I might have got 90% of it off, a few little hairy bits showed up when I painted it. I did my best so fingers crossed those few bits wont be a problem.

Lorian

TomsMom wrote: »

Thanks everyone.

I brushed and scraped, brushed and scraped and it looked as though it had all gone.

Have done 2 undercoats and one top coat of Weathershield and it looks as though I might have got 90% of it off, a few little hairy bits showed up when I painted it. I did my best so fingers crossed those few bits wont be a problem.

Touch up time next year :rolleyes:

TomsMom

Lorian wrote: »

Touch up time next year :rolleyes:

Well, so be it. We'll wait and see. I did what I could and I thought I'd got it all off, just so happens I didn't quite manage it. Pobody's nerfect!