Problem with soil stack

kelly1234

Hoping someone may be able to give some advice regarding this problem.....Will warn you that am not very technically minded in relation to pipes/plumbing so will explain as best as I can!
I have a soil stack (that comes directly from upstairs bathroom down into sitting room) that is boxed in. For a while i have noticed that the carpet + furniture in that section of room (near stack) is slightly damp, as is skirting board. Pulled up carpet + investigated as best as could, thought might have leak, used home emergency cover - plumber took boxing cover off, couldnt find leak. He suspected might be condensation - as pipe is boxed in and water frequently going down? Have kept an eye on pipe, hadnt put boxing back until yesterday... put boxing back on (just sheets of thin wood) and noticed this morning that there were water marks at bottom of wood, removed boxing and sure enough there is condensation around the bottom section of pipe and the plastic ring thing that is around the base of the pipe. It smells damp around the area but only damp, not sewage or anything. At a loss as to what to do next or how to solve problem-any ideas or anyone had same experience? Thanks

ormus

not much you can do apart from insulating the whole inside of the boxed in pipework.

Canucklehead

Hi.

Why would you get condensation on an empty pipe? (soil)


Post a photo?

GSR.

bobthedambuilder

Haven't heard of this happening before but it's plausible - you have cold water coming down the soil pipe, and if there's warm moist air in the downstairs room it could condense on the cold pipe. Is there any reason for the air in the sitting room to be particularly moist? e.g. poor ventilation, moisture generating heating (open gas fire, calor gas heater), kept at a high temperature all the time?

As ormus says, you could try insulation - pack the box with rockwool or similar, or wrap the pipe from floor to as high as you can reach with pipe insulation.

keystone

I have seen this before - twice. The first time in a roofspace where an extension had meant extending (in plastic) and angling the old vent over at 45 degrees in order to exiut the roof in a sensible place. The 45 degree element was constantly dripping in winter. Cold air dropping down the vent and warm moist air in the roof condensing on it.

The second occasion was similar to that which the OP describes - is it a 1970s property with an internal soil/vent stack? Same problem - not so much cold water in the pipe when loo(s) were flushed but cold air entering and settling in it. Insulating the pipe may prevent warm moist air getting to it but just might also result in cold and soggy insulation and I'm not sure which is a worse prospect.

OP - can you open up the area around the stack where it passes the level of the floor firstly to to allow any condensation to drop below floor level (assuming its a suspended floor of course) and secondly to ventilate. That would prevent condensation contaminating your carpets etc and if it goes into a void under the floor there will be no harm done.

Alternatively can you put a vent cowl (CLICKY) on top of the vent to allow it to do its job but minimise the amount of cold air dropping straight down it.

Best I can up with without seeing it or a pic as CH requested.

Cheers

kelly1234

thanks for the replies/advice - yes Keystone, it is a 1970's house with internal stack! Its boxed in. Floor is concrete. Have taken photo but not sure how to attach photo to show you? Where would the vent cowl go? Is vent normally in roof?

missprice

Canucklehead wrote: »

Hi.

Why would you get condensation on an empty pipe? (soil)


Post a photo?

GSR.

sorry already answered above and me just repeating same answer oops

keystone

kelly1234 wrote: »

thanks for the replies/advice - yes Keystone, it is a 1970's house with internal stack! Its boxed in. Floor is concrete.

In that case if the cowl doesn't work you'll need a condensation trap but to fit it the stack needs to be cut and a small section removed to take the trap. It will also need a hole through to the outside to drain the trap. It's not a DIY job TBH.

Have taken photo but not sure how to attach photo to show you?

Probably no needed now you've said its concrete.

Where would the vent cowl go? Is vent normally in roof?

Right on the top of the 110mm pipe sticking out of your roof (that would not be your flue if you've got warm air heating). I'll find you a pic.


Cheers.

Canucklehead

Hi.

I'd still like to see a photo.!


GSR

kelly1234

Have got pic ready+waiting but cannot work out how to attach it! do you reckon this would be a plumbing job or builder type job?

keystone

Go to imageshack.

In the browse, select, upload boix hit the browse button.

Navigate to the image concerned on your pc and click on it.

After a while (depending on image size) the image details will appear in the bar.

Then click Upload now. Taskbar will gradually go green whilst you are uploading.

When its finished you'll see a thumbnail of your image plus a number of linking options

RIGHT click on the Forum Code one then coipy and paste that into a post on here.

It'll look a bit like this:

[U R L=h t t p ://imageshack.us/photo/my-images/39/xxxxxx.jpg/]B]I M G[/Bhttp://img39.imageshack.us/img39/5892/xxxxxxx.jpg[/I M G][/U R L]

Notice I've put spaces in between the URL, IMG and http bits where I've bolded it. Thats to make it post as text and you need to post it as text because you don't have a high enough postcount yet to post links.

Someone can then take the spaces out (me prolly if I'm still here) and we can see the image.

Anyone who can clim a ladder can put a cowl on. The condensation trap is a bit more challenging. The builder will only his plumber round to do it who will grumble and think its beneath him and to be fair a labourer with a bit of sense could do it as long as the boss has confidence tht he can make the seals properly twixt the severed stack and the condensation trap. It'll be a two man job too as there will be a fair amount of heaving and swearing going on. You will probably find that the boxing won't survive intact if they are to cut the stack cleanly so there'll be remedial work too. Get a cowl put on first and see what happens would be my advice.

HTH

Cheers