Flat roof problem

[trevthesparky]

We have a bay window with a flat roof in our bedroom, it has sprung a leak. A roofer was next door today so I asked him to take a look, he said it was only part felted by the rip off merchants who did it originally(surprisingly enough they have gone bust so they will not be coming back to rectify it) He said he could put it right for £80 and pulled out a can of paint from his van.
Now, because I don't like paying people for stuff I can do myself and that this paint must be easily available I did a bit of digging on tintenet and found a liquid DPM from wickes for £11 a tin. So my question is, is this stuff really appropriate for exterior use and will it give a lasting repair?
Hopefully a kindly roofer out there will offer me his/her advice

 

[dilly]

ACRYPOL.should last between 5 to 10 years

 

[^woody^]

because I don't like paying people for stuff I can do myself

But you are happy for someone to spend their time going up there and diagnosing a problem

I think that there is the small issue of actually confirming what the problem is before brushing anything on - as a liquid coating may not be the correct option

Anyway, Acrypol is about £40 a tin, , so plus time, clearing the surface, a brush rag and turps, then £80 does not seem too bad

 

[trevthesparky]

The guy was up there for less than 1 minute, add to that the fact that he was already working next door and it hardly means I caused him some huge inconvenience does it

 

[freddiemercurystwin]

Bet you didn't tell him you only wanted his advice though did you?

 

[trevthesparky]

Incorrect. That's precisely what I asked him for.