Come back to my car to find an 8" crack running from the bottom of the windscreen up diagonally on the drivers side. No marks before hand, parked up the car, came back 2 hours later and it appeared. No other marks so I have no idea how it happened...

It's not directly in my line of sight.

Insurance (TPF&T with Aviva) doesn't cover windscreens.

A - Do I need to get it replaced for the MOT?

B - How much will a replacement cost? Unfortunately it has a built in section for the rain sensor, so I fear it may be expensive...

C - I assume a repair is not possible?

D - If I don't need to get it fixed... what problems could I have in the future with it?

D - The crack can become longer/bigger due to the chassis flex

Quote from ATHome :

D - The crack can become longer/bigger due to the chassis flex

or weather (rapid temperature changes).

1st: In germany you wouldn't pass MOT (TÜV) with a crack in the screen. IDK about GB but the windscreen is an important part of the car, so I assume you (more your car) won't pass.

2nd: THere are methods to repair punctual chips in the screen, but a crack cannot be repaired, no matter how big.
EDIT: seems very small cracks can nowadays be repaired as well! not 8 inches though I'm afraid..

3rd: Since the screen is made of security glass it might just break even more and fall into millions of pieces at 75 miles during the night in heavy rain.... you get the picture :-) I never saw something like this happen, but it CAN.
Edit: I have seen it... a friend had a very small chip in the rear window of his polo. He was driving along as suddenly he heard a noise and had a hole the size of a fist in the window. Rest was crackling apart.

Depending on the car model you might get a new windscreen from the same car from some scrapyard, then take it to a garage and have it replaced.

greetz

der sorry-for-the-bad-news butz

Quote from Jakg :

Come back to my car to find an 8" crack running from the bottom of the windscreen up diagonally on the drivers side. No marks before hand, parked up the car, came back 2 hours later and it appeared. No other marks so I have no idea how it happened...

It's not directly in my line of sight.

Insurance (TPF&T with Aviva) doesn't cover windscreens.

A - Do I need to get it replaced for the MOT?

B - How much will a replacement cost? Unfortunately it has a built in section for the rain sensor, so I fear it may be expensive...

C - I assume a repair is not possible?

D - If I don't need to get it fixed... what problems could I have in the future with it?

A - Usually yes.

B - Try Autglass for a quote, see if it's cheaper elsewhere.

C - Depends on the size - if it's a small crack, it could be possible, but usually it can't be repaired unless its small or a chip. Once again, try Autoglass.

D - Over time, it will get bigger. Best to get it seen to now just in case you could get it repaired before it cracks into something unrepairable.

I'd replace it. Safety glass is weird, all sorts of innocuous bumps can shatter it, you don't want that happening at speed.

That said, I rented a car with a crack about that size in the windscreen in France a couple of years back, drove it for two weeks (mostly on rural French roads so it got the shit kicked out of it) and it didn't get any worse.

Quote from Jakg :

A - Do I need to get it replaced for the MOT?

If the damage is larger than 40mm in the sweep area of the wipers then yes it will fail the mot

Ouch, I would have thought it will fail its MOT.

Autoglass have this quick internative thing on their website that gives you an idea of what can be done.

Can't believe you got that car, spent all that cash then skimp on insurance, TPF&T :biggrinfl oh dear.

Quote from garph :

Can't believe you got that car, spent all that cash then skimp on insurance, TPF&T :biggrinfl oh dear.

Fully Comp was a grand extra, couldn't really justify at the time.

Just called Autoglass - they want £615 for one, or £434 with my special insurance discount, which might of made me panic just a little... Auto Windscreens want £248 for it which isn't quite so bad.

2 front tyres + car tax + this = an expensive month

D Couldn't you go somewhere else for an answer to your question?

Quote from G!NhO :

D Couldn't you go somewhere else for an answer to your question?

Yes, yes I could. And I did. But cross posting on different forums gets much more information than posting on one.

Thanks for the input

Calling carglass or whatever wasn't an option?

Quote from G!NhO :

Calling carglass or whatever wasn't an option?

I never trust anyone who is trying to sell me a product or service to give me 100% correct information.

I had no idea what would or would not fail an MOT crack wise, and couldn't find anything when I searched, nor could I find any sort of information on what could or could not be repaired.

These all seem stupid questions... once you've been through it before.

Quote from der butz :

...

3rd: Since the screen is made of security glass it might just break even more and fall into millions of pieces at 75 miles during the night in heavy rain.... you get the picture :-) I never saw something like this happen, but it CAN.
Edit: I have seen it... a friend had a very small chip in the rear window of his polo. He was driving along as suddenly he heard a noise and had a hole the size of a fist in the window. Rest was crackling apart.
...

Windshields are made of laminated glass so they don't break into millions of pieces when damaged. Usually all the other windows on a car are made of simple tempered glass so they shatter easily.

Yup, all windscreens since about 1960 have been laminated (possibly by law?), so it's VERY hard to break them and puncture them. Bricks can and do hit screens, shattering the screen, but stopping the brick coming into the car. Even animals are repelled by the abilities of the laminate. Up to a point!

The crack will get worse. It might let it moisture. In the winter, freeze-thaw will almost certainly break it.

Repairing it is a cover up - the crack will still be there even if it is 'filled'. But it would get you through an MoT (although it still might pass if it isn't in the prescribed line of view (which might not be the same as the area you actually use)).

I've had a crack on my screen for 4 months now. It's gradually grown, though seems to have stopped now. I don't want to replace it because a) I don't want to spend the £50 excess on my car and b) I'm after a new car anyway (via a loan) and the old one isn't worth bothering with...

Worth getting a quote from Autoglass or similar for a replacement - mention the sensor. Often they'll come to your place of work, or home, and replace it for you whilst you're not present, so it's not much of a hassle (except in monetary terms).

Quote from Jakg :

2 front tyres + car tax + this = an expensive month

I'll pay for yours if you'll pay for mine. I blew the differential on my car, you don't even wanna know what that is going to cost.

Going from memory, if any crack or stone chip measures larger than 1/2" (13mm) accross and is within the sweep of the window wipers then it is an instant fail, even if it is directly behind the rear view mirror so it cannot be seen when sat in the drivers seat (as happened to me once) unless of course they dont notice it, which is doubtful.

Well, after Autoglasses initial £615 megaquote, i've now got it down to £223.25 with Auto Windscreens, booked up for the week after next... Now if only I knew why it just spontaneously broke

Quote from Jakg :

Well, after Autoglasses initial £615 megaquote, i've now got it down to £223.25 with Auto Windscreens, booked up for the week after next... Now if only I knew why it just spontaneously broke

A small stone flying off the tyre of the car driving by? Happens quite often here. Although small stone might not be enough, I once saw a small truck with double rear tyres which had a half of a brick(!) stuck inbetween. It was making quite a loud noise with every revolution of the tyre when it was hitting the road. Was scary as hell driving behind it

I also came to the car to see a small crack some time ago. But its tiny, doesn't grow, so I don't bother...

this is always a good place to start for MOT queries

http://www.motuk.co.uk/manual/contents.htm

oh and not MOT related but on a lot of modern cars the manufacturers regard any bonded glass as a structural member when they're doing their design so any substantial crack could in theory put extra load on other areas, unlikely to cause any problems but before i sold the garage we did have a customer who's rear bonded windscreen had been broken (by a thrown brick ) and he drove it like that for a few days till he hit a sharp bump and his front windscreen went as well.

Quote from Jakg :

Well, after Autoglasses initial £615 megaquote, i've now got it down to £223.25 with Auto Windscreens, booked up for the week after next... Now if only I knew why it just spontaneously broke

How did you get the price down so much?

Quote from Jakg :

Well, after Autoglasses initial £615 megaquote, i've now got it down to £223.25 with Auto Windscreens, booked up for the week after next... Now if only I knew why it just spontaneously broke

Silly question - For that much less, does it include your fancy sensor?

Quote from piggy501 :

Silly question - For that much less, does it include your fancy sensor?

Yes it does. I've been offered an Auto Windscreens screen with rain sensor at trade price which is less than 10% of the original Autoglass quote so i'm going to see it I can find someone to fit it and (hopefully) save even more...

You must know people or have superior haggling skills - that's extremely cheap.