Blocked fire up - black liquid appeared

almeida24

I had an old gas fire in my house which I had taken out about 6 months ago. There was a little amount of soot at the bottom and I have recently had the hole in the chimney breast blocked up (just using plasterboard) and plastered over about 2 weeks ago.

I have just been up to the house (i'm not currently living in it yet as I am still doing it up) and noticed there looks like a leak from where the hole has been blocked up. Initially it looked like rain and because of all the rain in my area lately this is what I thought it was. However, when I put my finger in it, it was really black and looked like oil. I'm guessing there has been condensation built up which has soaked the soot and produced this black liquid, or could it be something else?

Should I have done something before I blocked it up to prevent condensation occurring? Any ideas what I should do now?

KateLiana27

You need an air vent fitted. Otherwise the difference in temperature between the cold chimney and warm room will cause condensation to form within the chimney inner walls, and turn into nasty black liquid as it washes off old soot. Damp problems are very likely in blocked-up chimneys with no air vents so I'd get it sorted now. It's a simple job that I'm sure you could DIY, just don't ask me how

almeida24

KateLiana27 wrote: »

You need an air vent fitted. Otherwise the difference in temperature between the cold chimney and warm room will cause condensation to form within the chimney inner walls, and turn into nasty black liquid as it washes off old soot. Damp problems are very likely in blocked-up chimneys with no air vents so I'd get it sorted now.

Thanks for your help. Do I need to get someone out to fit the vent or can they be fitted myself? Also, would I have to remove the plasterboard and re-plaster?

erdd2

OP What did "it" smell of?

KateLiana, where should the vents you suggest be placed. I have had old back boiler removed with chimney swept and blocked and have had no condensation /black liquid problems (2 years now)...but your advice has me wondering if I should be doing something else. Thanks

almeida24

erdd2 wrote: »

OP What did "it" smell of?

KateLiana, where should the vents you suggest be placed. I have had old back boiler removed with chimney swept and blocked and have had no condensation /black liquid problems (2 years now)...but your advice has me wondering if I should be doing something else. Thanks

I didn't notice any smell to be honest.

martinthebandit

Put a vent in from outside, fairly simple and straightforward job

almeida24

martinthebandit wrote: »

Put a vent in from outside, fairly simple and straightforward job

The chimney is in the middle of the house so how would I do this? Or can I put the vent at the top of the chimney rather than at the bottom?

martinthebandit

almeida24 wrote: »

The chimney is in the middle of the house so how would I do this?

OK maybe from outside is not the best idea then, looks like you will have to put one in internally, have a look on screwfix or similar for air vents