Air pressure test Scotland

[Pm1987]

I need to perform a final pressure test for the council to witness and sign off. This is the last item required for completion but I’m at my wits end with it. 
 

Bunged  off the last connection before septic tank and the two vents. Using the hand bulb I’m getting no increase of pressure on gauge. 
 

I have tested the bulb and pump on a spare bit of pipe with no issues. 
 

I have filled the line under the house with water and timed it with no leaks. 
 

the plumbing has been operational for around a year with no water leaks and no smells. 
 

am I missing something here ? 
 

any ideas from anyone would be greatly appreciated. 

[Barryscotland]

Surely each press of your hand primer will just be blowing bubbles through your traps? Council just wanted to see  an air test on our underground waste pipes before they where buried nothing after that

[jamieled]

Had the same problem for our test. Are you testing everything inside the house or just between manholes (couldn't figure out from your description). Do you have an mvhr system with condensate drain? Presumably no external high level vent pipe?

 

Get someone in the bathrooms/near sinks while you try to raise the pressure and see if it's bubbling up through a trap. The shower trap and drain is often the problem as it is often the shallowest trap. I had to seal down our shower drain and even then the pressure would only get to about 40mm before it bubbled up through the trap. Fine for BC sign off though .

[ProDave]

You will have a stack pipe (vent pipe) somewhere. You will need to get up on the roof and plug that.

 

Some councils are very hot on this, certainly Highland council in the Inverness area are. They WILL insist on seeing a drain pressure test, they first tested all underground drainage at foundation time, before the pipes were even covered in their trenches.  Later they tested the internal drainage, but because not all appliances were connected, they insisted on another drain test for completion.

 

Top tip, BUY your own drain pressure test kit, and test every bit of drainage as you connect it.  The very last thing you want is a hidden leak that will have you ripping your house apart to find it.

 

You should be able to pump the drains up to about 70mm only then will it start blowing bubbles through the traps.

[Pm1987]

The drains were tested before being back filled but the council insist on a test for the full system. The problem is I leak tested the system not pressure tested it before plaster boarding etc. 
 

The vent stacks have been bunged off with my bought test kit. 
 

I will try blocking off the shower / bath traps. 
 

How long does it normally take to pump the system by hand ? 

[jamieled]

I guess it depends on the size of your system, but for me in the order of 10-20s!

[ProDave]

Check your shower traps.  Mine are the sort you service from above with a lift out "bucket" that forms the trap.  I found on first pump up the pressure went and it would not pump up.  The pressure had lifted the "bucket" up from the trap and it no longer sealed.  I had to improvise a sliver of wood to slide in to hold the bucket down for the pressure test.  Lousy design if you ask me.

 

I do hope you get it sorted, but that's why i say do a proper pressure test before anything is covered.

[Hastings]

@ProDave I have only just learnt that a drains test needs to be submitted with our completion application and wondered exactly what the paperwork is that BC required for your sign-off and who can perform the test?

 

The drains were installed and covered 2 years ago. Annoying they didn't mention it as part of our agreed inspection plan in which they just require photos of main structural stages instead of inspection visits.

[ProDave]

1 hour ago, Hastings said:

@ProDave I have only just learnt that a drains test needs to be submitted with our completion application and wondered exactly what the paperwork is that BC required for your sign-off and who can perform the test?

 

The drains were installed and covered 2 years ago. Annoying they didn't mention it as part of our agreed inspection plan in which they just require photos of main structural stages instead of inspection visits.

BC inspector just visited and I did the pressure test while he watched.  I bought a drain test kit when we built the first house 19 years ago.  The one I have came with 3 drain bungs, a manometer and a hand pump to pressurise the drains.

 

They might sign off with a drain test by someone else and not witnessed by them but I would not know who that might be.

[jamieled]

There are certain plumbers who are on an approved persons list who can certificate a drains test in Scotland without BC supervision. They appear to be few and far between though and I suspect for most it is not worth the hasle. There is a list somewhere on a Scottish government building regs related website which I found a while back but I can't remember where. Something like 'list of approved verifiers of construction'.

 

If you can I would consider doing it yourself and get BC to observe. If there are any problems I can see the approved persons route being expensive.

 

 

 

[ProDave]

9 minutes ago, jamieled said:

If you can I would consider doing it yourself and get BC to observe. If there are any problems I can see the approved persons route being expensive.

 

My advice is test as you go.  You don't want to be finding out right at the end there is a leak somewhere, but you don't have the faintest idea where.  So each time I added a bit more to the drainage piping, I would test it again to ensure the new bit does not have a leak.

 

BC witnessed 3 tests on mine, one for all the outside underground drain runs, one for the bulk of the in house pipes, but before most of the bathrooms were fitted (blanked off ends pipe runs) and one on completion with everything connected.