adding trellis onto top of block wall to extend height

[FEvans]

I have a block wall in my garden and want to add around 40cm height to it with some trellis just to get a bit of privacy. Just wondering the best way to do this.

Ie should i lay a piece of 2x1 batten across top of wall and attach baton to this ( i assume thats not going to be very string however)

2nd option is to fix some vertical lengths of batten to wall ie 40cm below and 40cm above and fix trellis to that.

or is there some other option I should consider.

 

[conny]

I would go for option 2 but extend the wall length to about 80cm below to give it a bit more strength.

 

[FEvans]

Cheers what size screws I need to attach a 4.5 cm square batton to brickwork

 

[conny]

4.5cm =45mm so screw/bolt would need to be around 70mm to give a reasonable grip into the block work. Depending on how thick the block work is I may be tempted to go to 80mm or even 90mm