What's happened to my new lawn?

Hello all,
I am hoping someone can advise, i have had new turf laid about 8-10 weeks ago, i have done all the right things:
Kept the lawn moist, not too wet or too dry, i have cut it using sharp blade, and started with height, lowering the mower gradually. But it looks my lawn is not looking healthy as it did after the first 2 or 3 cuts... it is becoming thin and seeing lots of dead grass building up or light patchy spots...
By looking at the pictures attached, can you suggest what might be the problem and what I can do about it please? I haven't fertilized it, I didn't think it needed to be, this early?

 

It looks like its been cut to short to me and scorched by the sun ?.

 

I never checked underneath as it didn't lift with ease and therefore i never forced it...

We had good amount of rain this Saturday in London, so it's had a good soak over the weekend.
Previously, I have had the sprinkler on for 1 and a half hours, twice a week during the last 2 weeks. In the weeks we had high temperture, 3 times a week. Is that enough?

I have a Bosh mower, i have kept it at '5' during the last 2 cuts.

Is the lawn in bad condition for 8-10 weeks?

 

How does lawn get scorched by the sun? i always cut it at 4pm onward. Wondering if 5 setting on the mover is too low?

 

I can only presume cutting short exposes the new shoots that are not tough enough for strong sunlight, ive just cut my new turf on setting number three this setting is quite high on my mower i like to keep my lawn at this height as it looks like your when ive cut it shorter,

Please note i am no expert far from it this is my own observations over the last three years take them with a pinch of salt ,

This is no 3 setting on my mower.

 

Thanks guys, appreciate the help. I will water it more (especially seeing that good weather is expected this week) and raise the blades to say 6.

Have i done lasting damage? or can this be repaired?

 

Gardenflop, I would raise the cutting height and give the lawn a feed. I would use a liquid nitrogen feed for now.

No, you've not caused lasting damage.

 

Sorry pal, I just cannot be calling you gardenflop ...so, um Sid, Derek, John or Peter - what is underneath that turf? Are you on a new build site maybe - where there is a fair bit of builders rubble?

 

if You feed the lawn make sure you check the label for iron/fe.
If the product contains this you need to avoid those nice slabs or else they will be stained.

 

As you seem to have been struggling with your lawn since 2013 (reading back) I think the answer is probably in the underlying soil quality.

 

Yeah... lol, i have been having issues since 2013, hence the username.
We just got our home refurbished along with the garden hence the new lawn. We took out the old lawn, put new top soil and laid fresh lawn, the landscaper actually commented how good the soil was, so i think its me :-(

2013, it certainly was me as i put too much fertiliser and now it seems i may have cut it to short?
I am so P'd off with myself, its just a lawn... how can i not look after a lawn..arhhhhh

Anyway, this is the plan.. I will water profusely this week and i will raise the height of the mover on the next cut... I am very apprehensive about using fertiliser just yet. If anyone can mess this up it will be me.

 

Raise the cut and feed.....liquid feed; you will not damage the lawn by overdosing. Then give us feedback gardenflop

 

ha ha, you guys have managed to put a smile on my face... OK deal... IF i can fix the lawn, i will change my profile name.

I have been Google'íng what liquid feed to use, any advise? i had my eye on the Scotts lawn builder but that's not liquid and i'm following your advice for the liquid feed.