External render maintanance and painting/sealing

[RodgerTheBodger]

I had the house rendered 4 years ago and left it for about a year before painting it with a single coat of Dulux Wethershield. I'm now working out that this wasn't enough!
There are a few cracks and plenty of algae and looking at other threads for help, I'm thinking of scraping at the cracks before filling and removing the algae with fungicide, then adding a coat (or two?) of paint. Someone told me that the water based paints do not act as a sealant and therefore water soaks into the brickwork and finds it's way inside the house.
Question 1 - Is it true? I'd like to prevent this.
Question 2 - Are my preparation measures for a new coat of paint enough?
Question 3 - Which paint (or sealant) should I use to waterproof the house?

Cheers!

 

[joe-90]

How many houses are there out there without any render and without any problems? Unless you live on a windswept coat where the rain comes sideways it isn't any use whatsoever.

 

[RodgerTheBodger]

Joe 90, the render was applied for the aesthetic quality rather than for protection.