Gutter downpipe into concrete

[iburnell]

I had a new boiler installed in garage. I wanted the condensate pipe to go into a nearby gutter downpipe but it all froze up last winter so the boiler couldn't discharge. The downpipes are old cast-iron (and have split). The problem is the downpipe goes straight under the path i.e. is concreted in. If there was a drain cover at the base I assume I could just route some polypipe from the boiler condensate to the existing cover. Can the base be converted i.e. could you crack open the concrete and put in a drain cover which I could then add the boiler pipe?. I could then change the gutter downpipe to plastic at the same time. Is it put underground to try to prevent freezing up in winter?

 

[Hugh Jaleak]

If you're happy to dig out the concrete then remove enough to expose the underground drain. Work carefully to avoid any damage to the pipework under the concrete. Should find a 4" drain, would assume it'll be clayware, if iron downpipes are fitted to an older property. Dig out enough to expose the drain and allow room for a gulley and connection.

Use an angle grinder with a stone disc to (carefully) cut through the clay pipe. Fit a suitable connector to join 110mm plastic to the clay, and install a gulley. Make good concrete. Fit new downpipe and condensate drain as required. Condensate is better uprated to 32 or even 40mm waste pipe for the external run, but keep as short as possible outside the building to try and prevent it freezing during colder months.

 

[cotswoldbuilders]

Its not a good idea running the outlet pipe into the gutter down pipe, we were called out not long ago to a flooded house.
The lower pipe blocked up with leaves etc, causing the water to flood back through.

 

[iburnell]

Thanks for the replies - if it doesn't exhaust into the downpipe the only other option is to put into a soakaway in the ground. Looking at the boiler installation guide (Worcester Greenstar) it says there should be " an air break must be installed in the 43mm pipe work, between the boiler condensate outlet and the drainpipe outside the property to avoid flooding during adverse weather conditions"

I rang a builder last night and he suggested not breaking the concrete but cutting the old cast iron pipe presumably at ground level and then attaching a new Upvc downpipe to it - which seems to me like a good idea

 

[Hugh Jaleak]

Be aware, condensate and metal pipework dont mix, routing the condensate into an iron pipe will quickly corrode the iron. For that reason condensate is run in plastic, at least to a suitable point where flow from other discharges will dilute the condensate. If discharging into rainwater drain, there would be no flow during dry weather to dilute the condensate.

 

[iburnell]

Thanks for the tip Hugh - I appreciate it

I see this only as a temporary measure. Eventually the garage will be converted with a downstairs cloakroom added . Hopefully then the condensate can be combined to the toilet waste going straight to the external drainage system