Soil pipe stack quotes

GT60

Hi I have asked two companies for replacement soil pipe and a new drain pipe to be installed running from the roof gutter as it dont have one 
One quote is £840 and is by a plumber recommended by a heating engineer company i use  and the other is £300 is a company i know nothing about and messaged me after asking on a local facebook page for quotes.
Advice please and i am in Manchester
Thanks

tacpot12

£840 is a fair price for a recommended tradesperson. This is a job that you want doing properly. A leak under the house could cause all sort of smells and problems. 

victor2

£300 for a stranger on fartbook to do you the job?

plumb1_2

£840 is a bit ott imo, around the £500 mark is a fair price . It’s only a days work
make sure they start off with a drain rodding boss at ground level

Socialworkguy

I'm having having bathroom done. We changed layout to go from joint shower and bath to separate. As they laid the pipes pipes told me they have to change the soil stack (internal in bathroom and downstairs toilet) to ensure proper drainage of the water from shower and bath as the pipes were 35mm drainage and not big enough.

Anyway, they said this costs £750 to replace the stack internal, although although we're already doing my bathroom so seems expensive to me. 

Section62

GT60 said:

Hi I have asked two companies for replacement soil pipe and a new drain pipe to be installed running from the roof gutter as it dont have one 

Just to be clear, you want a separate rainwater downpipe from the gutter?  If so, that will involve some extra work as they will need to do some work on the undergound pipework... but you need to do this anyway as the gutter shouldn't discharge into the stack in the way it currently does.

Also, I'd be suspicious about the material type of the 4" pipe coming out of the wall with a bend (presumably from the toilet) It looks like it has been joined to the sloping pipe with some kind of patent connector - so the bend might not be uPVC and therefore needs extra care to get a leak-free join.

Hopefully they won't be replacing like for like either - the slope on that pipe (and the waste pipe below it) is far too steep and looks really ugly.  This is the kind of job you get when someone 'cheap' does the work, rather than someone who knows and understands the regulations and best working practices.