possible screw in soil pipe running inside house

beolight

hi all

looks like im in trouble

the waste pipe from upstairs shower runs inside house down to kitchen

i had plasters in a couple of months ago and used this opportunity to open up the wall to add some rockwool to muffle the noise a bit, i slabbed it once using screws going battens and gun o prene in the middle and then left to come back and find plaster adding another slab of plaster and screwing into battens at sides and middle.

i jokingly said to him i hope he hasnt screwed into the soil pipe, i do recall a water spill at the time of plastering but this was promptly mopped up

i should add that this floor was covered with junckers flooring so i am very careful with water spillage

after a while this area was basically used for storage and some boxes were stacked up against the wall, i finally cleared out this area to create space and to my horror i noticed a deep black water stain on junckers floor , it was just in one area near the external corner, initially i thought damm the water wasnt mopped up properly and because no skirting boards were fixed it must of pooled around the concrete hole where waste pipe was buried and gradually seeped into the floorboard

i removed the skirting and cut a bit of the plasterboard away to get my hand under to check for dampness and sure enough it was damp, i used some rags to mop it up and then used hairdryer to dry the area.

problem solved so i thought i went about trying to remove the water stain but i think it is permanent now

the next day i checked the area again this time the wood batten was damp/slimy again, the ground area felt a little damp, a film of black covering my fingers, this area was bone dry the day previous having used the hair dryer on it for over an hour

so now im thinking damm a screw must of penetrated the pipe somewhere and water is seeping out of the pipe close to the wooden batten and travelling all the way down to the floor

i am going to open up the wall tomorrow to investigate further, i dont want to contact plaster ontill im sure its his problem

if as i suspect it is screw damage,how can i repair it?

i should add the house is semi detached and this waste pipe may also be neighbours waste pipe

should i remove screw and cut out section of pipe and replace it or simply try patch it with mastic or is there some other solution

as always any advise suggestions most appreciated

spidy

if you go to any good builders providers/plumbing merchent tell them the size of the pipe and ask for a bracket called a 'boss' for it. this wraps around the pipe and seals the hole. it should only cost a couple of euro.

beolight

thanks for reply

just finished opening up, some brown type mushrooms etc found

i dont think its a screw penetrating it, as all joints on waste pipe till it straigthens are dry

looks like where pipe is coming up from ground and joined up to waste with bend joint the seal is gone or broke as dampness is evident here

dried everything up with hair dryer and left shower running for a good while(must apologise to neighbours/ power shower) and dampness back again

hopefully cutting through the bend will allow me to remove the joint

anybody got any thoughts before i cut???

RicardoSmith

If the dampness is near the joint I'd suspect the joint. Perhaps a rubber seal was twisted when fitted. Sometimes these move slightly and thats all it takes to break the seal. Feel for you though. Water leaks, and drains can be a right pain.

rooferPete

Hi,

I am finding this hard to picture in my mind, you have checked and there is no screw driven into the pipe and you are happy there is no water coming down from above ?

When water especially from showers and hand basins run into a soil stack the water runs down around the pipe, so if you are sure there is nothing on the soil stack it is possible that a lazy plumber or labourer did not use a ring in the joint where the stack meets the bend to take the water out to the drain.

The chances are the water is backing up to the concrete floor from the joint, which means there would be no benefit in cutting the pipe, try and expose the pipe as it goes into the floor, take care because if you damage the pipe you will have a serious problem of not being able to use the bathroom at all.

.

beolight

thanks to everyone your replies have been most helpful

"If the dampness is near the joint I'd suspect the joint. Perhaps a rubber seal was twisted when fitted. Sometimes these move slightly and thats all it takes to break the seal. Feel for you though. Water leaks, and drains can be a right pain."

i suspect/hope this is the scenario, i left shower running for half an hour and dampness only felt at the bottom joint where pipe comes up from concrete. my doubt is that after turning shower off the dampness continued which may indicate a damaged pipe under the floor.

there is a new baby due in the next few weeks and this is the last thing i need

I am finding this hard to picture in my mind, you have checked and there is no screw driven into the pipe and you are happy there is no water coming down from above ?

pipe bone dry as is the rock wool wrapped around it, only possible area screw could of penetrated was down at bottom anywhere else the pipe was too far back in the wall for any length of screw to reach

The chances are the water is backing up to the concrete floor from the joint, which means there would be no benefit in cutting the pipe, try and expose the pipe as it goes into the floor, take care because if you damage the pipe you will have a serious problem of not being able to use the bathroom at all.

i dont get this, if joint is faulty it will need replacing i presume, i cant see any other way of doing this other than cutting above the 2 bend joints and refitting 2 new ones

i have exposed the pipe as much as possible, there is a small crater around the pipe as it comes up from floor now, the backs of my hands are red raw from scraping against concrete blocks

rooferPete

Hi,

I'll PM you a possible fix.

.

beolight

thanks all

problem solved now hopefully

we cut into pipe and replaced both bends using a collar

looks like the builder knew there was a problem as he had applied some mastic to the underside of the bend

same builders also managed to shoot a couple of nails into my gas pipe feed with their nail gun when putting on wainscoat wood panels on the stairs

i wonder what other surprises lay in store for me