Bricks crumbling

[fm322085]

Hello, I am the most un-knowledgeable person in the world when it comes to any DIY so apologies if I ask over simple questions...

I have got a few damaged bricks on my side wall, they seem to have weathered over the last cold winter... The wall is rendered in some weird way, I think water got behind some of the render and that has caused the damage. The bricks have crumbled about a 3rd through.

I am going to remove any loose parts of the wall and want to build up the damaged bricks to the level of the rest of the rendered wall... What consistency of cement/sand should I use to build this up?

I also have a small patch where some of the mortar has rotted away? What is the ratio for fixing this?

Do I need to do anything else?

I will be grateful for any advice

 

[Deluks]

How are your gutters? Any joints or leaks above the affected areas, also do not quite understand 'wall has been rendered in a wierd way'
Pics would help.

 

[fm322085]

The problem areas are about 2-3 foot above ground... I'll check the guttering but I think it is fine...

Could it be rising damp? if so how would this be fixed on an external wall? In the same way as internal?

The wall has been rendered, just not smoothly, its got a very rough finish, looks lots of little twigs scattered all over it. I'll upload some pictures when I am at home tomorrow.

Its the same in about 3-4 places along the entire wall...

I am presuming the damp will be the meither but is the actual brick repair an easy enough job?