New Build chimney problems

Hardwood82

We have a new house and got a boiler stove fitted. We've had some problems so far with cracking of the chimneybreast and been assured by the builder but also by someone who we had look at it and I trust that it's nothing to worry about.

Today I noticed that there was a brown mark appearing around where the flue expander attaches into the concrete chimney. Later a funny smell developed and the stain has gotten much larger, I've attached a couple of photos.

I'm worried that the concrete flue has been damaged and that tar is leaking into the sand and lime surrounding the concrete flue.

The chimney construction is concrete surrounded by sand and lime as I stated, I was told there was no need for a flue liner. Unfortunately we had a bad batch of wood which may have been a bit damp, we have had a fire almost every night since mid December and have not had the chimney swept.

Any help would be much appreciated! I'm going to contact our builder tomorrow as the house was only completed in December

DOCARCH

If you are really worried I would suggest getting a specialist company to do a report and camera survey of the chimney...even if just for peace of mind. At least then you would have an independent opinion.

no1murray

A double insulated flue liner from stove to top of chimney would be best practice. Should solve any problems.

Calahonda52

How do u know the chimney liner is concrete?
How do you know the infill is sand and lime?
Could the lner be ceramic?

Anyway the stove flue is not properly fitted and the flue may only have been designed for a gas fire.

If it is concrete liner then the stove gasses will have cracked it.
Get it checked

kennethmoran

What kind of concrete head did the builder install over chimney breat

Hardwood82

Thanks all for the advice, i don't think I know enough about this subject so It looks like I'll have to get it checked and maybe go back to the builder