Should I use weed killer before turfing ?

KL

I am going to turf the sloped area in the below picture but notice there are a lot of weeds so presume it’s best to get rid of these first to save them growing through the new turf. Is it ok to use weed killer or would this have an effect on the turf once laid , ie would it contaminate the soil. 

punkdoc

You can use weedkiller without problems.
I think you may struggle to grow grass on that slope, due to shade from tree and shed and the very dry soil you will have from the tree roots.

Hostafan1

IMHO  grass on that slope will be nothing but agro for you, too many edges, trees, fences . It'll just be a mowing obstacle course

KL

Ah ok, I didn’t realise that, this area has annoyed me for years so wanted to get it tidied up. Any suggestions?

K67

Look for ground cover plants for dry shade, bound to be a hardy geranium that will suit.
But do keep anything you plant well watered until they are established 

Suesyn

Ground cover plants that don't mind dry shade, bugle is one that springs to mind, comes in purple or green leaved varieties, seems to grow in any soil and even tolerates being walked on occasionally. 

Fire

woodruff and heucheras

KL

I will go and have a look at the ground cover plants as I agree the grass would be difficult to maintain but i have got to the stage now that I just want the area covered as it’s an eyesore and I’m home for a few weeks so time to do something with it. I also felt that If I grassed the area it would make the garden look a bit bigger. 

Are these plants Mentioned hardy And how should I space them ? 

Bijdezee

A Wildflower mix? 

KL

Bijdezee said:

A Wildflower mix? 

I looked at wild flower turf but it was over 3 x the price of standard Turf. Do you mean seeds ? 

Fairygirl

All those plants mentioned are hardy and easy, and will only require minimal maintenance once established. You can add spring bulbs into the mix as they will be fine, assuming there's enough light there - it looks like the big tree has  high enough canopy even if it's evergreen. You would plant them along with the other plants wherever possible, but it's easy enough to push some in at a later date.
Spacing depends on the eventual size of each plant, so it's a case of doing a little research. The general conditions you have will dictate though - some will grow slightly less, and some may grow slightly more. 

Another common, but excellent ground cover plant is Cotoneaster. On a  slope, it knits the ground together too, although that isn't particularly steep.