If I dont paint an exterior cement render wall will it eventually leak?

[bbabythai]

I had a window removed and put brickworks in and they did cement rendering inside and outside. 

 

I will obviously soon be painting the inside. But if I dont get around to doing the outside will the cement render break down eventually and cause dampness/ leaking 

 

thanks

[bankruatsteve]

It will break down.  Maybe not cause any leaks but it will look like cr@p.

 

[ThaiFelix]

Dampness will creep through.  We have 2 meter boundary walls surrounding our house.  Both sides are rendered, our side is painted with a good quality paint but the neighbours side is not.  After the rainy season bubbles the size of 10 baht coins appear under the paint on our side...it is a build up of dampness that has crept through the wall in more porous spots.

[ravip]

A coat of waterproofing before painting would help.

[lopburi3]

3 minutes ago, ThaiFelix said:

Dampness will creep through.  We have 2 meter boundary walls surrounding our house.  Both sides are rendered, our side is painted with a good quality paint but the neighbours side is not.  After the rainy season bubbles the size of 10 baht coins appear under the paint on our side...it is a build up of dampness that has crept through the wall in more porous spots.

Are you sure that is not rising damp from underground?  Or both?  For OP would make sure to paint it and if not smooth make sure paint can penetrate to fill any voids.  We had workers use very poor paint on an outside wall once and over time in can into the room and destroyed inside paint.  Unless they used waterproof cement or white cement for render it will leak over time.   

[RJRS1301]

Do not use house paint, use concrete paint, wash the surface, remove all dust particles, a concrete sealer / undercoat then two two top coats for good result

Using ordinary house paint is a waste of time and money

 

Edited July 29, 2020 by RJRS1301

[ThaiFelix]

On 7/29/2020 at 4:46 PM, lopburi3 said:

Are you sure that is not rising damp from underground?  Or both?  For OP would make sure to paint it and if not smooth make sure paint can penetrate to fill any voids.  We had workers use very poor paint on an outside wall once and over time in can into the room and destroyed inside paint.  Unless they used waterproof cement or white cement for render it will leak over time.   

No I doubt its rising damp as all of the bubbles are high up on the walls.  There is no bubbles/blisters at all in the lower part.  I also have very large ground beams and being solid concrete I would imagine would be difficult for dampness to travel through.  That wall also faces the south west where we get the worst of our weather from.

 

If in doubt with anything like this I usually tend to add a lanko product mixed with the render or even in the paint.  I cant remember the number but it is a latex similar to Bondcrete we use in Australia.  It can also be used to join/cover old cement/concrete with new with great success.

[ThaiFelix]

On 7/29/2020 at 4:50 PM, RJRS1301 said:

Do not use house paint, use concrete paint, wash the surface, remove all dust particles, a concrete sealer / undercoat then two two top coats for good result

Using ordinary house paint is a waste of time and money

 

I used Dulux Weathershield for all my outside and boundary walls and highly recommend it as it still looks like new after 7 years.

[Beardog]

I used Dulux Weathershield for all my outside and boundary walls and highly recommend it as it still looks like new after 7 years.

 

Choice of Champions!

[473geo]

First use concrete primer, we put two coats, then two coats of exterior paint, still looks good a few years later