Thread: How long for render to dry?

Originally Posted by Tubby2

Gday all,
I have had my front brick retaining wall cement rendered about 6 or so weeks ago and the renderer told me to leave it for over 4 weeks before I paint it so the render can fully cure. He told me to give it a little spry with water every now and then to help stop it drying too quickly and prevent cracks. He told me that rain would also help it.

Ive never seen a builder doing that.. standing around with a spray bottle..
Sounds like one of those, "if you dont do that, and it cracks, its your fault" things..

Originally Posted by Tubby2

My problem is at the moment that it wont stop friggin raining so I can get a coat of paint on it, which I want to do so I can fill the garden bed behind it and put all my plants in before summer ends.

My question is how long after it rains does it take for render to dry out enough to paint.
I'm assuming that the water hasnt gone too deeep into the render but what time frame should I be looking at?

Cheers

Is the paint water based?

It was the renderer that told me to spray it with water and I think he said to use a hose.
From memory he said that keeping the outside wet allows the inside to dry better and avoid cracks.

The Paint is Taubmans all weather acrylic.

I bit the bullet and since we had a hot sunny day on saturday and a hot sunny day sunday I decided to put my first coat on and within 10mins of me starting I heard the rumbling of thunder in the distance. I had just finished the first coat and about 20 mins later we got hit with a massive thunder storm and hail. The one that was on the news that hit western Sydney with golf ball sized hail stones.

The paint held up quite well with the exception of the last metre or so that had a couple of run marks but the rest must have dried enough.

Maybe I should go and paint a wall out west and break the drought.

Originally Posted by Tubby2

It was the renderer that told me to spray it with water and I think he said to use a hose.
From memory he said that keeping the outside wet allows the inside to dry better and avoid cracks.

Mortar has initial set at in 45 minutes and final set at 10 hours, I dont think it will move after that unless the bricks it is stuck onto move in some way.

Minor shrinkage cracks do happen in mortar but its usually due to the clay in the sand shrinking as it sets.

Renders use washed sand so I dont see how it could crack..

Tubby, if you are backfilling with soil behind the wall make sure that you waterproof first with Ormonoid or equivalent. Otherwise the outside face of the wall will always be damp and may end up getting a lot of algae growing etc.