Should our stack vent pipe have an open section

[Caapro]

Hello - i wonder if someone can help answer this question for me please.

Ive been looking into our extention attic space recently regards its ventilation, with the hot weather upon us once again. I soon came to the conclusion that it had good clean soffit vents all the way around but no vents inside the actual loft space. There is a small opening from the loft space to the garage area so that is something also there is a small extractor fan in the downstairs small toilet that would help somewhat. But then i noticed this on the waste water stack vent pipe - pictures below. Now from my common sense prespective and reading on what the purpose of a stack vent does, this would be quiet the cowboy job? Like i said before i think its there as to help vent the attic space - or am i totally off the ball on this one. Not sure i very happy with the fact sewage gas has been permeating thou out our home for a very long time.

Pipe to the left is upstairs loo outlet the smaller white one is the upstairs sink and bath outlet, the big one going up is obv the stack vent part that travels about another 2 or 3 meters out of the roof and the bottom one leads to the downstairs loo and everything else then the sewer. That thing hacked onto the stack vent i do not know about, what is it?

http://www.flickr.com/photos/caapro/sets/72157634572844909/ link to 4 photos

Thanks
Craig

 

[Charnwood]

At some point a strap boss was fitted to accept a waste pipe. Subsequently the pipe was removed, but the boss left open. Plugging it should be OK.

Remove the white bit as it's incomplete, then plug the (looks like) ring-seal grey joint.

 

[Bosswhite]

Its a Solvent Weld Pipe boss, should be connected to a waste pipe, looks to me as though whoever fitted it changed their mind and left it open.
Get a Solvent Weld Screw on Socket plug for it,

I dont think its a bodged up job posing as an Air Admittance Valve

 

[Charnwood]

Looks more like a push-fit ring seal joint to me. It is not flat as solvent bosses normally are, it has a bump (seal housing).

.

Push-fit waste plug:

 

[Caapro]

Ahh thanks alot for the replies and help

until i can get a proper plug ive used some think plastic and a cable tie

would covering this have any effect on the system? positive or negative apart from the air quality i mentioned before

Thanks
Craig

 

[Madrab]

Nope, surplus to requirements - does the white piece of pipe come out of the grey boss as it looks like a solvent adapter that pushed into the boss, take that out then use the push fit plug that Charnwood has kindly pictured