Dreaded drains test

[Bop]

The final hurdle of the house build and the drain test will just not work! Drains hold water fine but not air! My question is has any one had this problem and were building control happy to accept a water test instead of an air test?

 

[stevetheplumber]

normally a water test on drain and air test on soils

 

[Spanner2k7]

When you do the air test, does the stack pressurise or does the water level go completly down straight away.

 

[Bop]

Drops straight away!

 

[Spanner2k7]

have you put a bung in the top of the stack??

 

[gaspastemania]

House bash sites i have worked on building control just flush toilet to see if it holds for a few seconds they stare at it , if it drops tho then missing something somewhere .

 

[justlead1]

Hi. As has bean said, a bung in vent and at base, then flushing a cistern will result in the pan water level holding above the norm. (the hose from the water gauge can be passed through the pan trap and used) However is the system is large putting a bag in at access point allow the testing of smaller areas of the system. Which allow one to identify the problem area. Soapy water brushed on joints will show leaks when the system is under pressure.

 

[Garyjohn]

Hi in the past i've found pan connectors hold water tight but not air tight could be the problem.

 

[Bop]

There's a bung in stack. Got one bathroom to test but the other 2 wont!All drains r under 4 inch of concrete so proving difficult! What I don't get it how they hold water fr hours but when air test them the gauge plumets, doesn't hold at anything so surely that would suggest quite a big leak? But we no it can't be a big leak cos they hold water?

 

[jtsplumbing]

Make sure that the test hose has-not got a pin hole ! try another pice of hose.

 

[Bop]

Th hose must be ok cos parts of the house are holding fine.

 

[Bernie2]

If the drains are fireclay try a smoke bomb. But do not use on plastic.

 

[mcniven]

just turn upstairs tap on a dribble and do the test down stairs takes u a few attempts to get it right

 

[justlead1]

Now there is a proper answer. Along with putty up the hose end. But when test is finished and all parties are happy, make sure you disconnect from U tube whilst the establishment are present. On occasions the small canister type blow lamps have been used (so i have heard)to assist (not alight) but dangling by string within the sealed stack, opened just enough to maintain stability of the u gauge. However this requires at least a NVQ level 111. Good Luck

 

[Spanner2k7]

If it is holding on a water test, but not and air test, then that would say a major leak above the branch.

Does the stack vent to atomsphere or is there an AAV fitted to the stack??